libwebp: Sync with upstream 1.2.1

Changes: https://chromium.googlesource.com/webm/libwebp/+/1.2.1/NEWS

70 files changed, 1649 insertions, 1139 deletions

diff --git a/thirdparty/README.md b/thirdparty/README.md
index 25d2e1cfe3..a6ab5a8cd1 100644
--- a/thirdparty/README.md
+++ b/thirdparty/README.md
@@ -292,13 +292,13 @@ Files extracted from upstream source:
 ## libwebp
 
 - Upstream: https://chromium.googlesource.com/webm/libwebp/
-- Version: 1.1.0 (d7844e9762b61c9638c263657bd49e1690184832, 2020)
+- Version: 1.2.1 (9ce5843dbabcfd3f7c39ec7ceba9cbeb213cbfdf, 2021)
 - License: BSD-3-Clause
 
 Files extracted from upstream source:
 
-- `src/*` except from: .am, .rc and .in files
-- AUTHORS, COPYING, PATENTS
+- `src/*` except from: `.am`, `.rc` and `.in` files
+- `AUTHORS`, `COPYING`, `PATENTS`
 
 Important: The files `utils/bit_reader_utils.{c,h}` have Godot-made
 changes to ensure they build for Javascript/HTML5. Those
diff --git a/thirdparty/libwebp/AUTHORS b/thirdparty/libwebp/AUTHORS
index 0d70b7fb2a..30abde0326 100644
--- a/thirdparty/libwebp/AUTHORS
+++ b/thirdparty/libwebp/AUTHORS
@@ -1,9 +1,15 @@
 Contributors:
+- Aidan O'Loan (aidanol at gmail dot com)
 - Alan Browning (browning at google dot com)
 - Charles Munger (clm at google dot com)
+- Cheng Yi (cyi at google dot com)
 - Christian Duvivier (cduvivier at google dot com)
+- Christopher Degawa (ccom at randomderp dot com)
+- Clement Courbet (courbet at google dot com)
 - Djordje Pesut (djordje dot pesut at imgtec dot com)
 - Hui Su (huisu at google dot com)
+- Ilya Kurdyukov (jpegqs at gmail dot com)
+- Ingvar Stepanyan (rreverser at google dot com)
 - James Zern (jzern at google dot com)
 - Jan Engelhardt (jengelh at medozas dot de)
 - Jehan (jehan at girinstud dot io)
@@ -20,6 +26,7 @@ Contributors:
 - Mislav Bradac (mislavm at google dot com)
 - Nico Weber (thakis at chromium dot org)
 - Noel Chromium (noel at chromium dot org)
+- Oliver Wolff (oliver dot wolff at qt dot io)
 - Owen Rodley (orodley at google dot com)
 - Parag Salasakar (img dot mips1 at gmail dot com)
 - Pascal Massimino (pascal dot massimino at gmail dot com)
@@ -38,5 +45,7 @@ Contributors:
 - Vikas Arora (vikasa at google dot com)
 - Vincent Rabaud (vrabaud at google dot com)
 - Vlad Tsyrklevich (vtsyrklevich at chromium dot org)
+- Wan-Teh Chang (wtc at google dot com)
 - Yang Zhang (yang dot zhang at arm dot com)
 - Yannis Guyon (yguyon at google dot com)
+- Zhi An Ng (zhin at chromium dot org)
diff --git a/thirdparty/libwebp/src/dec/alpha_dec.c b/thirdparty/libwebp/src/dec/alpha_dec.c
index bce735bfc2..0b93a30b32 100644
--- a/thirdparty/libwebp/src/dec/alpha_dec.c
+++ b/thirdparty/libwebp/src/dec/alpha_dec.c
@@ -183,7 +183,7 @@ const uint8_t* VP8DecompressAlphaRows(VP8Decoder* const dec,
   assert(dec != NULL && io != NULL);
 
   if (row < 0 || num_rows <= 0 || row + num_rows > height) {
-    return NULL;    // sanity check.
+    return NULL;
   }
 
   if (!dec->is_alpha_decoded_) {
diff --git a/thirdparty/libwebp/src/dec/buffer_dec.c b/thirdparty/libwebp/src/dec/buffer_dec.c
index 3cd94eb4d9..4786cf0ddb 100644
--- a/thirdparty/libwebp/src/dec/buffer_dec.c
+++ b/thirdparty/libwebp/src/dec/buffer_dec.c
@@ -102,7 +102,7 @@ static VP8StatusCode AllocateBuffer(WebPDecBuffer* const buffer) {
     int stride;
     uint64_t size;
 
-    if ((uint64_t)w * kModeBpp[mode] >= (1ull << 32)) {
+    if ((uint64_t)w * kModeBpp[mode] >= (1ull << 31)) {
       return VP8_STATUS_INVALID_PARAM;
     }
     stride = w * kModeBpp[mode];
@@ -117,7 +117,6 @@ static VP8StatusCode AllocateBuffer(WebPDecBuffer* const buffer) {
     }
     total_size = size + 2 * uv_size + a_size;
 
-    // Security/sanity checks
     output = (uint8_t*)WebPSafeMalloc(total_size, sizeof(*output));
     if (output == NULL) {
       return VP8_STATUS_OUT_OF_MEMORY;
@@ -156,11 +155,11 @@ VP8StatusCode WebPFlipBuffer(WebPDecBuffer* const buffer) {
   }
   if (WebPIsRGBMode(buffer->colorspace)) {
     WebPRGBABuffer* const buf = &buffer->u.RGBA;
-    buf->rgba += (buffer->height - 1) * buf->stride;
+    buf->rgba += (int64_t)(buffer->height - 1) * buf->stride;
     buf->stride = -buf->stride;
   } else {
     WebPYUVABuffer* const buf = &buffer->u.YUVA;
-    const int H = buffer->height;
+    const int64_t H = buffer->height;
     buf->y += (H - 1) * buf->y_stride;
     buf->y_stride = -buf->y_stride;
     buf->u += ((H - 1) >> 1) * buf->u_stride;
@@ -188,8 +187,7 @@ VP8StatusCode WebPAllocateDecBuffer(int width, int height,
       const int ch = options->crop_height;
       const int x = options->crop_left & ~1;
       const int y = options->crop_top & ~1;
-      if (x < 0 || y < 0 || cw <= 0 || ch <= 0 ||
-          x + cw > width || y + ch > height) {
+      if (!WebPCheckCropDimensions(width, height, x, y, cw, ch)) {
         return VP8_STATUS_INVALID_PARAM;   // out of frame boundary.
       }
       width = cw;
diff --git a/thirdparty/libwebp/src/dec/frame_dec.c b/thirdparty/libwebp/src/dec/frame_dec.c
index 04609a8e56..91ca1f8609 100644
--- a/thirdparty/libwebp/src/dec/frame_dec.c
+++ b/thirdparty/libwebp/src/dec/frame_dec.c
@@ -705,7 +705,7 @@ static int AllocateMemory(VP8Decoder* const dec) {
                         + cache_size + alpha_size + WEBP_ALIGN_CST;
   uint8_t* mem;
 
-  if (needed != (size_t)needed) return 0;  // check for overflow
+  if (!CheckSizeOverflow(needed)) return 0;  // check for overflow
   if (needed > dec->mem_size_) {
     WebPSafeFree(dec->mem_);
     dec->mem_size_ = 0;
diff --git a/thirdparty/libwebp/src/dec/io_dec.c b/thirdparty/libwebp/src/dec/io_dec.c
index e603f19c98..5ef6298886 100644
--- a/thirdparty/libwebp/src/dec/io_dec.c
+++ b/thirdparty/libwebp/src/dec/io_dec.c
@@ -25,21 +25,16 @@
 static int EmitYUV(const VP8Io* const io, WebPDecParams* const p) {
   WebPDecBuffer* output = p->output;
   const WebPYUVABuffer* const buf = &output->u.YUVA;
-  uint8_t* const y_dst = buf->y + io->mb_y * buf->y_stride;
-  uint8_t* const u_dst = buf->u + (io->mb_y >> 1) * buf->u_stride;
-  uint8_t* const v_dst = buf->v + (io->mb_y >> 1) * buf->v_stride;
+  uint8_t* const y_dst = buf->y + (size_t)io->mb_y * buf->y_stride;
+  uint8_t* const u_dst = buf->u + (size_t)(io->mb_y >> 1) * buf->u_stride;
+  uint8_t* const v_dst = buf->v + (size_t)(io->mb_y >> 1) * buf->v_stride;
   const int mb_w = io->mb_w;
   const int mb_h = io->mb_h;
   const int uv_w = (mb_w + 1) / 2;
   const int uv_h = (mb_h + 1) / 2;
-  int j;
-  for (j = 0; j < mb_h; ++j) {
-    memcpy(y_dst + j * buf->y_stride, io->y + j * io->y_stride, mb_w);
-  }
-  for (j = 0; j < uv_h; ++j) {
-    memcpy(u_dst + j * buf->u_stride, io->u + j * io->uv_stride, uv_w);
-    memcpy(v_dst + j * buf->v_stride, io->v + j * io->uv_stride, uv_w);
-  }
+  WebPCopyPlane(io->y, io->y_stride, y_dst, buf->y_stride, mb_w, mb_h);
+  WebPCopyPlane(io->u, io->uv_stride, u_dst, buf->u_stride, uv_w, uv_h);
+  WebPCopyPlane(io->v, io->uv_stride, v_dst, buf->v_stride, uv_w, uv_h);
   return io->mb_h;
 }
 
@@ -47,7 +42,7 @@ static int EmitYUV(const VP8Io* const io, WebPDecParams* const p) {
 static int EmitSampledRGB(const VP8Io* const io, WebPDecParams* const p) {
   WebPDecBuffer* const output = p->output;
   WebPRGBABuffer* const buf = &output->u.RGBA;
-  uint8_t* const dst = buf->rgba + io->mb_y * buf->stride;
+  uint8_t* const dst = buf->rgba + (size_t)io->mb_y * buf->stride;
   WebPSamplerProcessPlane(io->y, io->y_stride,
                           io->u, io->v, io->uv_stride,
                           dst, buf->stride, io->mb_w, io->mb_h,
@@ -62,7 +57,7 @@ static int EmitSampledRGB(const VP8Io* const io, WebPDecParams* const p) {
 static int EmitFancyRGB(const VP8Io* const io, WebPDecParams* const p) {
   int num_lines_out = io->mb_h;   // a priori guess
   const WebPRGBABuffer* const buf = &p->output->u.RGBA;
-  uint8_t* dst = buf->rgba + io->mb_y * buf->stride;
+  uint8_t* dst = buf->rgba + (size_t)io->mb_y * buf->stride;
   WebPUpsampleLinePairFunc upsample = WebPUpsamplers[p->output->colorspace];
   const uint8_t* cur_y = io->y;
   const uint8_t* cur_u = io->u;
@@ -133,7 +128,7 @@ static int EmitAlphaYUV(const VP8Io* const io, WebPDecParams* const p,
   const WebPYUVABuffer* const buf = &p->output->u.YUVA;
   const int mb_w = io->mb_w;
   const int mb_h = io->mb_h;
-  uint8_t* dst = buf->a + io->mb_y * buf->a_stride;
+  uint8_t* dst = buf->a + (size_t)io->mb_y * buf->a_stride;
   int j;
   (void)expected_num_lines_out;
   assert(expected_num_lines_out == mb_h);
@@ -186,7 +181,7 @@ static int EmitAlphaRGB(const VP8Io* const io, WebPDecParams* const p,
         (colorspace == MODE_ARGB || colorspace == MODE_Argb);
     const WebPRGBABuffer* const buf = &p->output->u.RGBA;
     int num_rows;
-    const int start_y = GetAlphaSourceRow(io, &alpha, &num_rows);
+    const size_t start_y = GetAlphaSourceRow(io, &alpha, &num_rows);
     uint8_t* const base_rgba = buf->rgba + start_y * buf->stride;
     uint8_t* const dst = base_rgba + (alpha_first ? 0 : 3);
     const int has_alpha = WebPDispatchAlpha(alpha, io->width, mb_w,
@@ -210,7 +205,7 @@ static int EmitAlphaRGBA4444(const VP8Io* const io, WebPDecParams* const p,
     const WEBP_CSP_MODE colorspace = p->output->colorspace;
     const WebPRGBABuffer* const buf = &p->output->u.RGBA;
     int num_rows;
-    const int start_y = GetAlphaSourceRow(io, &alpha, &num_rows);
+    const size_t start_y = GetAlphaSourceRow(io, &alpha, &num_rows);
     uint8_t* const base_rgba = buf->rgba + start_y * buf->stride;
 #if (WEBP_SWAP_16BIT_CSP == 1)
     uint8_t* alpha_dst = base_rgba;
@@ -276,9 +271,9 @@ static int EmitRescaledYUV(const VP8Io* const io, WebPDecParams* const p) {
 static int EmitRescaledAlphaYUV(const VP8Io* const io, WebPDecParams* const p,
                                 int expected_num_lines_out) {
   const WebPYUVABuffer* const buf = &p->output->u.YUVA;
-  uint8_t* const dst_a = buf->a + p->last_y * buf->a_stride;
+  uint8_t* const dst_a = buf->a + (size_t)p->last_y * buf->a_stride;
   if (io->a != NULL) {
-    uint8_t* const dst_y = buf->y + p->last_y * buf->y_stride;
+    uint8_t* const dst_y = buf->y + (size_t)p->last_y * buf->y_stride;
     const int num_lines_out = Rescale(io->a, io->width, io->mb_h, p->scaler_a);
     assert(expected_num_lines_out == num_lines_out);
     if (num_lines_out > 0) {   // unmultiply the Y
@@ -303,46 +298,57 @@ static int InitYUVRescaler(const VP8Io* const io, WebPDecParams* const p) {
   const int uv_out_height = (out_height + 1) >> 1;
   const int uv_in_width  = (io->mb_w + 1) >> 1;
   const int uv_in_height = (io->mb_h + 1) >> 1;
-  const size_t work_size = 2 * out_width;   // scratch memory for luma rescaler
+  // scratch memory for luma rescaler
+  const size_t work_size = 2 * (size_t)out_width;
   const size_t uv_work_size = 2 * uv_out_width;  // and for each u/v ones
-  size_t tmp_size, rescaler_size;
+  uint64_t total_size;
+  size_t rescaler_size;
   rescaler_t* work;
   WebPRescaler* scalers;
   const int num_rescalers = has_alpha ? 4 : 3;
 
-  tmp_size = (work_size + 2 * uv_work_size) * sizeof(*work);
+  total_size = ((uint64_t)work_size + 2 * uv_work_size) * sizeof(*work);
   if (has_alpha) {
-    tmp_size += work_size * sizeof(*work);
+    total_size += (uint64_t)work_size * sizeof(*work);
   }
   rescaler_size = num_rescalers * sizeof(*p->scaler_y) + WEBP_ALIGN_CST;
+  total_size += rescaler_size;
+  if (!CheckSizeOverflow(total_size)) {
+    return 0;
+  }
 
-  p->memory = WebPSafeMalloc(1ULL, tmp_size + rescaler_size);
+  p->memory = WebPSafeMalloc(1ULL, (size_t)total_size);
   if (p->memory == NULL) {
     return 0;   // memory error
   }
   work = (rescaler_t*)p->memory;
 
-  scalers = (WebPRescaler*)WEBP_ALIGN((const uint8_t*)work + tmp_size);
+  scalers = (WebPRescaler*)WEBP_ALIGN(
+      (const uint8_t*)work + total_size - rescaler_size);
   p->scaler_y = &scalers[0];
   p->scaler_u = &scalers[1];
   p->scaler_v = &scalers[2];
   p->scaler_a = has_alpha ? &scalers[3] : NULL;
 
-  WebPRescalerInit(p->scaler_y, io->mb_w, io->mb_h,
-                   buf->y, out_width, out_height, buf->y_stride, 1,
-                   work);
-  WebPRescalerInit(p->scaler_u, uv_in_width, uv_in_height,
-                   buf->u, uv_out_width, uv_out_height, buf->u_stride, 1,
-                   work + work_size);
-  WebPRescalerInit(p->scaler_v, uv_in_width, uv_in_height,
-                   buf->v, uv_out_width, uv_out_height, buf->v_stride, 1,
-                   work + work_size + uv_work_size);
+  if (!WebPRescalerInit(p->scaler_y, io->mb_w, io->mb_h,
+                        buf->y, out_width, out_height, buf->y_stride, 1,
+                        work) ||
+      !WebPRescalerInit(p->scaler_u, uv_in_width, uv_in_height,
+                        buf->u, uv_out_width, uv_out_height, buf->u_stride, 1,
+                        work + work_size) ||
+      !WebPRescalerInit(p->scaler_v, uv_in_width, uv_in_height,
+                        buf->v, uv_out_width, uv_out_height, buf->v_stride, 1,
+                        work + work_size + uv_work_size)) {
+    return 0;
+  }
   p->emit = EmitRescaledYUV;
 
   if (has_alpha) {
-    WebPRescalerInit(p->scaler_a, io->mb_w, io->mb_h,
-                     buf->a, out_width, out_height, buf->a_stride, 1,
-                     work + work_size + 2 * uv_work_size);
+    if (!WebPRescalerInit(p->scaler_a, io->mb_w, io->mb_h,
+                          buf->a, out_width, out_height, buf->a_stride, 1,
+                          work + work_size + 2 * uv_work_size)) {
+      return 0;
+    }
     p->emit_alpha = EmitRescaledAlphaYUV;
     WebPInitAlphaProcessing();
   }
@@ -356,7 +362,7 @@ static int ExportRGB(WebPDecParams* const p, int y_pos) {
   const WebPYUV444Converter convert =
       WebPYUV444Converters[p->output->colorspace];
   const WebPRGBABuffer* const buf = &p->output->u.RGBA;
-  uint8_t* dst = buf->rgba + y_pos * buf->stride;
+  uint8_t* dst = buf->rgba + (size_t)y_pos * buf->stride;
   int num_lines_out = 0;
   // For RGB rescaling, because of the YUV420, current scan position
   // U/V can be +1/-1 line from the Y one.  Hence the double test.
@@ -383,15 +389,15 @@ static int EmitRescaledRGB(const VP8Io* const io, WebPDecParams* const p) {
   while (j < mb_h) {
     const int y_lines_in =
         WebPRescalerImport(p->scaler_y, mb_h - j,
-                           io->y + j * io->y_stride, io->y_stride);
+                           io->y + (size_t)j * io->y_stride, io->y_stride);
     j += y_lines_in;
     if (WebPRescaleNeededLines(p->scaler_u, uv_mb_h - uv_j)) {
-      const int u_lines_in =
-          WebPRescalerImport(p->scaler_u, uv_mb_h - uv_j,
-                             io->u + uv_j * io->uv_stride, io->uv_stride);
-      const int v_lines_in =
-          WebPRescalerImport(p->scaler_v, uv_mb_h - uv_j,
-                             io->v + uv_j * io->uv_stride, io->uv_stride);
+      const int u_lines_in = WebPRescalerImport(
+          p->scaler_u, uv_mb_h - uv_j, io->u + (size_t)uv_j * io->uv_stride,
+          io->uv_stride);
+      const int v_lines_in = WebPRescalerImport(
+          p->scaler_v, uv_mb_h - uv_j, io->v + (size_t)uv_j * io->uv_stride,
+          io->uv_stride);
       (void)v_lines_in;   // remove a gcc warning
       assert(u_lines_in == v_lines_in);
       uv_j += u_lines_in;
@@ -403,7 +409,7 @@ static int EmitRescaledRGB(const VP8Io* const io, WebPDecParams* const p) {
 
 static int ExportAlpha(WebPDecParams* const p, int y_pos, int max_lines_out) {
   const WebPRGBABuffer* const buf = &p->output->u.RGBA;
-  uint8_t* const base_rgba = buf->rgba + y_pos * buf->stride;
+  uint8_t* const base_rgba = buf->rgba + (size_t)y_pos * buf->stride;
   const WEBP_CSP_MODE colorspace = p->output->colorspace;
   const int alpha_first =
       (colorspace == MODE_ARGB || colorspace == MODE_Argb);
@@ -431,7 +437,7 @@ static int ExportAlpha(WebPDecParams* const p, int y_pos, int max_lines_out) {
 static int ExportAlphaRGBA4444(WebPDecParams* const p, int y_pos,
                                int max_lines_out) {
   const WebPRGBABuffer* const buf = &p->output->u.RGBA;
-  uint8_t* const base_rgba = buf->rgba + y_pos * buf->stride;
+  uint8_t* const base_rgba = buf->rgba + (size_t)y_pos * buf->stride;
 #if (WEBP_SWAP_16BIT_CSP == 1)
   uint8_t* alpha_dst = base_rgba;
 #else
@@ -470,7 +476,7 @@ static int EmitRescaledAlphaRGB(const VP8Io* const io, WebPDecParams* const p,
     int lines_left = expected_num_out_lines;
     const int y_end = p->last_y + lines_left;
     while (lines_left > 0) {
-      const int row_offset = scaler->src_y - io->mb_y;
+      const int64_t row_offset = (int64_t)scaler->src_y - io->mb_y;
       WebPRescalerImport(scaler, io->mb_h + io->mb_y - scaler->src_y,
                          io->a + row_offset * io->width, io->width);
       lines_left -= p->emit_alpha_row(p, y_end - lines_left, lines_left);
@@ -485,51 +491,58 @@ static int InitRGBRescaler(const VP8Io* const io, WebPDecParams* const p) {
   const int out_height = io->scaled_height;
   const int uv_in_width  = (io->mb_w + 1) >> 1;
   const int uv_in_height = (io->mb_h + 1) >> 1;
-  const size_t work_size = 2 * out_width;   // scratch memory for one rescaler
+  // scratch memory for one rescaler
+  const size_t work_size = 2 * (size_t)out_width;
   rescaler_t* work;  // rescalers work area
   uint8_t* tmp;   // tmp storage for scaled YUV444 samples before RGB conversion
-  size_t tmp_size1, tmp_size2, total_size, rescaler_size;
+  uint64_t tmp_size1, tmp_size2, total_size;
+  size_t rescaler_size;
   WebPRescaler* scalers;
   const int num_rescalers = has_alpha ? 4 : 3;
 
-  tmp_size1 = 3 * work_size;
-  tmp_size2 = 3 * out_width;
-  if (has_alpha) {
-    tmp_size1 += work_size;
-    tmp_size2 += out_width;
-  }
+  tmp_size1 = (uint64_t)num_rescalers * work_size;
+  tmp_size2 = (uint64_t)num_rescalers * out_width;
   total_size = tmp_size1 * sizeof(*work) + tmp_size2 * sizeof(*tmp);
   rescaler_size = num_rescalers * sizeof(*p->scaler_y) + WEBP_ALIGN_CST;
+  total_size += rescaler_size;
+  if (!CheckSizeOverflow(total_size)) {
+    return 0;
+  }
 
-  p->memory = WebPSafeMalloc(1ULL, total_size + rescaler_size);
+  p->memory = WebPSafeMalloc(1ULL, (size_t)total_size);
   if (p->memory == NULL) {
     return 0;   // memory error
   }
   work = (rescaler_t*)p->memory;
   tmp = (uint8_t*)(work + tmp_size1);
 
-  scalers = (WebPRescaler*)WEBP_ALIGN((const uint8_t*)work + total_size);
+  scalers = (WebPRescaler*)WEBP_ALIGN(
+      (const uint8_t*)work + total_size - rescaler_size);
   p->scaler_y = &scalers[0];
   p->scaler_u = &scalers[1];
   p->scaler_v = &scalers[2];
   p->scaler_a = has_alpha ? &scalers[3] : NULL;
 
-  WebPRescalerInit(p->scaler_y, io->mb_w, io->mb_h,
-                   tmp + 0 * out_width, out_width, out_height, 0, 1,
-                   work + 0 * work_size);
-  WebPRescalerInit(p->scaler_u, uv_in_width, uv_in_height,
-                   tmp + 1 * out_width, out_width, out_height, 0, 1,
-                   work + 1 * work_size);
-  WebPRescalerInit(p->scaler_v, uv_in_width, uv_in_height,
-                   tmp + 2 * out_width, out_width, out_height, 0, 1,
-                   work + 2 * work_size);
+  if (!WebPRescalerInit(p->scaler_y, io->mb_w, io->mb_h,
+                        tmp + 0 * out_width, out_width, out_height, 0, 1,
+                        work + 0 * work_size) ||
+      !WebPRescalerInit(p->scaler_u, uv_in_width, uv_in_height,
+                        tmp + 1 * out_width, out_width, out_height, 0, 1,
+                        work + 1 * work_size) ||
+      !WebPRescalerInit(p->scaler_v, uv_in_width, uv_in_height,
+                        tmp + 2 * out_width, out_width, out_height, 0, 1,
+                        work + 2 * work_size)) {
+    return 0;
+  }
   p->emit = EmitRescaledRGB;
   WebPInitYUV444Converters();
 
   if (has_alpha) {
-    WebPRescalerInit(p->scaler_a, io->mb_w, io->mb_h,
-                     tmp + 3 * out_width, out_width, out_height, 0, 1,
-                     work + 3 * work_size);
+    if (!WebPRescalerInit(p->scaler_a, io->mb_w, io->mb_h,
+                          tmp + 3 * out_width, out_width, out_height, 0, 1,
+                          work + 3 * work_size)) {
+      return 0;
+    }
     p->emit_alpha = EmitRescaledAlphaRGB;
     if (p->output->colorspace == MODE_RGBA_4444 ||
         p->output->colorspace == MODE_rgbA_4444) {
diff --git a/thirdparty/libwebp/src/dec/vp8_dec.c b/thirdparty/libwebp/src/dec/vp8_dec.c
index 57efb69041..5f405e4c2a 100644
--- a/thirdparty/libwebp/src/dec/vp8_dec.c
+++ b/thirdparty/libwebp/src/dec/vp8_dec.c
@@ -335,7 +335,7 @@ int VP8GetHeaders(VP8Decoder* const dec, VP8Io* const io) {
     io->scaled_width = io->width;
     io->scaled_height = io->height;
 
-    io->mb_w = io->width;   // sanity check
+    io->mb_w = io->width;   // for soundness
     io->mb_h = io->height;  // ditto
 
     VP8ResetProba(&dec->proba_);
@@ -494,13 +494,11 @@ static int GetCoeffsAlt(VP8BitReader* const br,
   return 16;
 }
 
-static WEBP_TSAN_IGNORE_FUNCTION void InitGetCoeffs(void) {
-  if (GetCoeffs == NULL) {
-    if (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kSlowSSSE3)) {
-      GetCoeffs = GetCoeffsAlt;
-    } else {
-      GetCoeffs = GetCoeffsFast;
-    }
+WEBP_DSP_INIT_FUNC(InitGetCoeffs) {
+  if (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kSlowSSSE3)) {
+    GetCoeffs = GetCoeffsAlt;
+  } else {
+    GetCoeffs = GetCoeffsFast;
   }
 }
 
diff --git a/thirdparty/libwebp/src/dec/vp8i_dec.h b/thirdparty/libwebp/src/dec/vp8i_dec.h
index 600a684410..20526a87c4 100644
--- a/thirdparty/libwebp/src/dec/vp8i_dec.h
+++ b/thirdparty/libwebp/src/dec/vp8i_dec.h
@@ -31,8 +31,8 @@ extern "C" {
 
 // version numbers
 #define DEC_MAJ_VERSION 1
-#define DEC_MIN_VERSION 1
-#define DEC_REV_VERSION 0
+#define DEC_MIN_VERSION 2
+#define DEC_REV_VERSION 1
 
 // YUV-cache parameters. Cache is 32-bytes wide (= one cacheline).
 // Constraints are: We need to store one 16x16 block of luma samples (y),
diff --git a/thirdparty/libwebp/src/dec/vp8l_dec.c b/thirdparty/libwebp/src/dec/vp8l_dec.c
index 93615d4ed2..73c3b54fff 100644
--- a/thirdparty/libwebp/src/dec/vp8l_dec.c
+++ b/thirdparty/libwebp/src/dec/vp8l_dec.c
@@ -559,8 +559,11 @@ static int AllocateAndInitRescaler(VP8LDecoder* const dec, VP8Io* const io) {
   memory += work_size * sizeof(*work);
   scaled_data = (uint32_t*)memory;
 
-  WebPRescalerInit(dec->rescaler, in_width, in_height, (uint8_t*)scaled_data,
-                   out_width, out_height, 0, num_channels, work);
+  if (!WebPRescalerInit(dec->rescaler, in_width, in_height,
+                        (uint8_t*)scaled_data, out_width, out_height,
+                        0, num_channels, work)) {
+    return 0;
+  }
   return 1;
 }
 #endif   // WEBP_REDUCE_SIZE
@@ -574,13 +577,14 @@ static int AllocateAndInitRescaler(VP8LDecoder* const dec, VP8Io* const io) {
 static int Export(WebPRescaler* const rescaler, WEBP_CSP_MODE colorspace,
                   int rgba_stride, uint8_t* const rgba) {
   uint32_t* const src = (uint32_t*)rescaler->dst;
+  uint8_t* dst = rgba;
   const int dst_width = rescaler->dst_width;
   int num_lines_out = 0;
   while (WebPRescalerHasPendingOutput(rescaler)) {
-    uint8_t* const dst = rgba + num_lines_out * rgba_stride;
     WebPRescalerExportRow(rescaler);
     WebPMultARGBRow(src, dst_width, 1);
     VP8LConvertFromBGRA(src, dst_width, colorspace, dst);
+    dst += rgba_stride;
     ++num_lines_out;
   }
   return num_lines_out;
@@ -594,8 +598,8 @@ static int EmitRescaledRowsRGBA(const VP8LDecoder* const dec,
   int num_lines_in = 0;
   int num_lines_out = 0;
   while (num_lines_in < mb_h) {
-    uint8_t* const row_in = in + num_lines_in * in_stride;
-    uint8_t* const row_out = out + num_lines_out * out_stride;
+    uint8_t* const row_in = in + (uint64_t)num_lines_in * in_stride;
+    uint8_t* const row_out = out + (uint64_t)num_lines_out * out_stride;
     const int lines_left = mb_h - num_lines_in;
     const int needed_lines = WebPRescaleNeededLines(dec->rescaler, lines_left);
     int lines_imported;
@@ -796,7 +800,8 @@ static void ProcessRows(VP8LDecoder* const dec, int row) {
       const WebPDecBuffer* const output = dec->output_;
       if (WebPIsRGBMode(output->colorspace)) {  // convert to RGBA
         const WebPRGBABuffer* const buf = &output->u.RGBA;
-        uint8_t* const rgba = buf->rgba + dec->last_out_row_ * buf->stride;
+        uint8_t* const rgba =
+            buf->rgba + (int64_t)dec->last_out_row_ * buf->stride;
         const int num_rows_out =
 #if !defined(WEBP_REDUCE_SIZE)
          io->use_scaling ?
@@ -947,7 +952,6 @@ static WEBP_INLINE void CopyBlock8b(uint8_t* const dst, int dist, int length) {
         break;
       default:
         goto Copy;
-        break;
     }
     CopySmallPattern8b(src, dst, length, pattern);
     return;
@@ -1515,7 +1519,7 @@ static int AllocateInternalBuffers32b(VP8LDecoder* const dec, int final_width) {
   assert(dec->width_ <= final_width);
   dec->pixels_ = (uint32_t*)WebPSafeMalloc(total_num_pixels, sizeof(uint32_t));
   if (dec->pixels_ == NULL) {
-    dec->argb_cache_ = NULL;    // for sanity check
+    dec->argb_cache_ = NULL;    // for soundness
     dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
     return 0;
   }
@@ -1525,7 +1529,7 @@ static int AllocateInternalBuffers32b(VP8LDecoder* const dec, int final_width) {
 
 static int AllocateInternalBuffers8b(VP8LDecoder* const dec) {
   const uint64_t total_num_pixels = (uint64_t)dec->width_ * dec->height_;
-  dec->argb_cache_ = NULL;    // for sanity check
+  dec->argb_cache_ = NULL;    // for soundness
   dec->pixels_ = (uint32_t*)WebPSafeMalloc(total_num_pixels, sizeof(uint8_t));
   if (dec->pixels_ == NULL) {
     dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
@@ -1667,7 +1671,6 @@ int VP8LDecodeImage(VP8LDecoder* const dec) {
   VP8Io* io = NULL;
   WebPDecParams* params = NULL;
 
-  // Sanity checks.
   if (dec == NULL) return 0;
 
   assert(dec->hdr_.huffman_tables_ != NULL);
diff --git a/thirdparty/libwebp/src/dec/webp_dec.c b/thirdparty/libwebp/src/dec/webp_dec.c
index 42d098874d..77a54c55d2 100644
--- a/thirdparty/libwebp/src/dec/webp_dec.c
+++ b/thirdparty/libwebp/src/dec/webp_dec.c
@@ -785,6 +785,13 @@ VP8StatusCode WebPDecode(const uint8_t* data, size_t data_size,
 //------------------------------------------------------------------------------
 // Cropping and rescaling.
 
+int WebPCheckCropDimensions(int image_width, int image_height,
+                            int x, int y, int w, int h) {
+  return !(x < 0 || y < 0 || w <= 0 || h <= 0 ||
+           x >= image_width || w > image_width || w > image_width - x ||
+           y >= image_height || h > image_height || h > image_height - y);
+}
+
 int WebPIoInitFromOptions(const WebPDecoderOptions* const options,
                           VP8Io* const io, WEBP_CSP_MODE src_colorspace) {
   const int W = io->width;
@@ -792,7 +799,7 @@ int WebPIoInitFromOptions(const WebPDecoderOptions* const options,
   int x = 0, y = 0, w = W, h = H;
 
   // Cropping
-  io->use_cropping = (options != NULL) && (options->use_cropping > 0);
+  io->use_cropping = (options != NULL) && options->use_cropping;
   if (io->use_cropping) {
     w = options->crop_width;
     h = options->crop_height;
@@ -802,7 +809,7 @@ int WebPIoInitFromOptions(const WebPDecoderOptions* const options,
       x &= ~1;
       y &= ~1;
     }
-    if (x < 0 || y < 0 || w <= 0 || h <= 0 || x + w > W || y + h > H) {
+    if (!WebPCheckCropDimensions(W, H, x, y, w, h)) {
       return 0;  // out of frame boundary error
     }
   }
@@ -814,7 +821,7 @@ int WebPIoInitFromOptions(const WebPDecoderOptions* const options,
   io->mb_h = h;
 
   // Scaling
-  io->use_scaling = (options != NULL) && (options->use_scaling > 0);
+  io->use_scaling = (options != NULL) && options->use_scaling;
   if (io->use_scaling) {
     int scaled_width = options->scaled_width;
     int scaled_height = options->scaled_height;
@@ -835,8 +842,8 @@ int WebPIoInitFromOptions(const WebPDecoderOptions* const options,
 
   if (io->use_scaling) {
     // disable filter (only for large downscaling ratio).
-    io->bypass_filtering = (io->scaled_width < W * 3 / 4) &&
-                           (io->scaled_height < H * 3 / 4);
+    io->bypass_filtering |= (io->scaled_width < W * 3 / 4) &&
+                            (io->scaled_height < H * 3 / 4);
     io->fancy_upsampling = 0;
   }
   return 1;
diff --git a/thirdparty/libwebp/src/dec/webpi_dec.h b/thirdparty/libwebp/src/dec/webpi_dec.h
index 24baff5d27..3b97388c71 100644
--- a/thirdparty/libwebp/src/dec/webpi_dec.h
+++ b/thirdparty/libwebp/src/dec/webpi_dec.h
@@ -77,6 +77,10 @@ VP8StatusCode WebPParseHeaders(WebPHeaderStructure* const headers);
 //------------------------------------------------------------------------------
 // Misc utils
 
+// Returns true if crop dimensions are within image bounds.
+int WebPCheckCropDimensions(int image_width, int image_height,
+                            int x, int y, int w, int h);
+
 // Initializes VP8Io with custom setup, io and teardown functions. The default
 // hooks will use the supplied 'params' as io->opaque handle.
 void WebPInitCustomIo(WebPDecParams* const params, VP8Io* const io);
diff --git a/thirdparty/libwebp/src/demux/anim_decode.c b/thirdparty/libwebp/src/demux/anim_decode.c
index 05dd707371..2bf4dcffe0 100644
--- a/thirdparty/libwebp/src/demux/anim_decode.c
+++ b/thirdparty/libwebp/src/demux/anim_decode.c
@@ -87,11 +87,19 @@ WebPAnimDecoder* WebPAnimDecoderNewInternal(
     int abi_version) {
   WebPAnimDecoderOptions options;
   WebPAnimDecoder* dec = NULL;
+  WebPBitstreamFeatures features;
   if (webp_data == NULL ||
       WEBP_ABI_IS_INCOMPATIBLE(abi_version, WEBP_DEMUX_ABI_VERSION)) {
     return NULL;
   }
 
+  // Validate the bitstream before doing expensive allocations. The demuxer may
+  // be more tolerant than the decoder.
+  if (WebPGetFeatures(webp_data->bytes, webp_data->size, &features) !=
+      VP8_STATUS_OK) {
+    return NULL;
+  }
+
   // Note: calloc() so that the pointer members are initialized to NULL.
   dec = (WebPAnimDecoder*)WebPSafeCalloc(1ULL, sizeof(*dec));
   if (dec == NULL) goto Error;
@@ -145,7 +153,7 @@ static int ZeroFillCanvas(uint8_t* buf, uint32_t canvas_width,
                           uint32_t canvas_height) {
   const uint64_t size =
       (uint64_t)canvas_width * canvas_height * NUM_CHANNELS * sizeof(*buf);
-  if (size != (size_t)size) return 0;
+  if (!CheckSizeOverflow(size)) return 0;
   memset(buf, 0, (size_t)size);
   return 1;
 }
@@ -166,7 +174,7 @@ static void ZeroFillFrameRect(uint8_t* buf, int buf_stride, int x_offset,
 static int CopyCanvas(const uint8_t* src, uint8_t* dst,
                       uint32_t width, uint32_t height) {
   const uint64_t size = (uint64_t)width * height * NUM_CHANNELS;
-  if (size != (size_t)size) return 0;
+  if (!CheckSizeOverflow(size)) return 0;
   assert(src != NULL && dst != NULL);
   memcpy(dst, src, (size_t)size);
   return 1;
@@ -346,12 +354,15 @@ int WebPAnimDecoderGetNext(WebPAnimDecoder* dec,
   {
     const uint8_t* in = iter.fragment.bytes;
     const size_t in_size = iter.fragment.size;
-    const size_t out_offset =
-        (iter.y_offset * width + iter.x_offset) * NUM_CHANNELS;
+    const uint32_t stride = width * NUM_CHANNELS;  // at most 25 + 2 bits
+    const uint64_t out_offset = (uint64_t)iter.y_offset * stride +
+                                (uint64_t)iter.x_offset * NUM_CHANNELS;  // 53b
+    const uint64_t size = (uint64_t)iter.height * stride;  // at most 25 + 27b
     WebPDecoderConfig* const config = &dec->config_;
     WebPRGBABuffer* const buf = &config->output.u.RGBA;
-    buf->stride = NUM_CHANNELS * width;
-    buf->size = buf->stride * iter.height;
+    if ((size_t)size != size) goto Error;
+    buf->stride = (int)stride;
+    buf->size = (size_t)size;
     buf->rgba = dec->curr_frame_ + out_offset;
 
     if (WebPDecode(in, in_size, config) != VP8_STATUS_OK) {
diff --git a/thirdparty/libwebp/src/demux/demux.c b/thirdparty/libwebp/src/demux/demux.c
index 1b3cc2e0a8..547a7725de 100644
--- a/thirdparty/libwebp/src/demux/demux.c
+++ b/thirdparty/libwebp/src/demux/demux.c
@@ -24,8 +24,8 @@
 #include "src/webp/format_constants.h"
 
 #define DMUX_MAJ_VERSION 1
-#define DMUX_MIN_VERSION 1
-#define DMUX_REV_VERSION 0
+#define DMUX_MIN_VERSION 2
+#define DMUX_REV_VERSION 1
 
 typedef struct {
   size_t start_;        // start location of the data
@@ -221,12 +221,16 @@ static ParseStatus StoreFrame(int frame_num, uint32_t min_size,
     const size_t chunk_start_offset = mem->start_;
     const uint32_t fourcc = ReadLE32(mem);
     const uint32_t payload_size = ReadLE32(mem);
-    const uint32_t payload_size_padded = payload_size + (payload_size & 1);
-    const size_t payload_available = (payload_size_padded > MemDataSize(mem))
-                                   ? MemDataSize(mem) : payload_size_padded;
-    const size_t chunk_size = CHUNK_HEADER_SIZE + payload_available;
+    uint32_t payload_size_padded;
+    size_t payload_available;
+    size_t chunk_size;
 
     if (payload_size > MAX_CHUNK_PAYLOAD) return PARSE_ERROR;
+
+    payload_size_padded = payload_size + (payload_size & 1);
+    payload_available = (payload_size_padded > MemDataSize(mem))
+                      ? MemDataSize(mem) : payload_size_padded;
+    chunk_size = CHUNK_HEADER_SIZE + payload_available;
     if (SizeIsInvalid(mem, payload_size_padded)) return PARSE_ERROR;
     if (payload_size_padded > MemDataSize(mem)) status = PARSE_NEED_MORE_DATA;
 
@@ -312,6 +316,7 @@ static ParseStatus ParseAnimationFrame(
   int bits;
   MemBuffer* const mem = &dmux->mem_;
   Frame* frame;
+  size_t start_offset;
   ParseStatus status =
       NewFrame(mem, ANMF_CHUNK_SIZE, frame_chunk_size, &frame);
   if (status != PARSE_OK) return status;
@@ -332,7 +337,11 @@ static ParseStatus ParseAnimationFrame(
 
   // Store a frame only if the animation flag is set there is some data for
   // this frame is available.
+  start_offset = mem->start_;
   status = StoreFrame(dmux->num_frames_ + 1, anmf_payload_size, mem, frame);
+  if (status != PARSE_ERROR && mem->start_ - start_offset > anmf_payload_size) {
+    status = PARSE_ERROR;
+  }
   if (status != PARSE_ERROR && is_animation && frame->frame_num_ > 0) {
     added_frame = AddFrame(dmux, frame);
     if (added_frame) {
@@ -446,9 +455,11 @@ static ParseStatus ParseVP8XChunks(WebPDemuxer* const dmux) {
     const size_t chunk_start_offset = mem->start_;
     const uint32_t fourcc = ReadLE32(mem);
     const uint32_t chunk_size = ReadLE32(mem);
-    const uint32_t chunk_size_padded = chunk_size + (chunk_size & 1);
+    uint32_t chunk_size_padded;
 
     if (chunk_size > MAX_CHUNK_PAYLOAD) return PARSE_ERROR;
+
+    chunk_size_padded = chunk_size + (chunk_size & 1);
     if (SizeIsInvalid(mem, chunk_size_padded)) return PARSE_ERROR;
 
     switch (fourcc) {
diff --git a/thirdparty/libwebp/src/dsp/alpha_processing.c b/thirdparty/libwebp/src/dsp/alpha_processing.c
index 819d1391f2..1892929a43 100644
--- a/thirdparty/libwebp/src/dsp/alpha_processing.c
+++ b/thirdparty/libwebp/src/dsp/alpha_processing.c
@@ -157,7 +157,8 @@ void WebPMultARGBRow_C(uint32_t* const ptr, int width, int inverse) {
   }
 }
 
-void WebPMultRow_C(uint8_t* const ptr, const uint8_t* const alpha,
+void WebPMultRow_C(uint8_t* WEBP_RESTRICT const ptr,
+                   const uint8_t* WEBP_RESTRICT const alpha,
                    int width, int inverse) {
   int x;
   for (x = 0; x < width; ++x) {
@@ -178,7 +179,8 @@ void WebPMultRow_C(uint8_t* const ptr, const uint8_t* const alpha,
 #undef MFIX
 
 void (*WebPMultARGBRow)(uint32_t* const ptr, int width, int inverse);
-void (*WebPMultRow)(uint8_t* const ptr, const uint8_t* const alpha,
+void (*WebPMultRow)(uint8_t* WEBP_RESTRICT const ptr,
+                    const uint8_t* WEBP_RESTRICT const alpha,
                     int width, int inverse);
 
 //------------------------------------------------------------------------------
@@ -193,8 +195,8 @@ void WebPMultARGBRows(uint8_t* ptr, int stride, int width, int num_rows,
   }
 }
 
-void WebPMultRows(uint8_t* ptr, int stride,
-                  const uint8_t* alpha, int alpha_stride,
+void WebPMultRows(uint8_t* WEBP_RESTRICT ptr, int stride,
+                  const uint8_t* WEBP_RESTRICT alpha, int alpha_stride,
                   int width, int num_rows, int inverse) {
   int n;
   for (n = 0; n < num_rows; ++n) {
@@ -290,9 +292,9 @@ static void ApplyAlphaMultiply_16b_C(uint8_t* rgba4444,
 }
 
 #if !WEBP_NEON_OMIT_C_CODE
-static int DispatchAlpha_C(const uint8_t* alpha, int alpha_stride,
+static int DispatchAlpha_C(const uint8_t* WEBP_RESTRICT alpha, int alpha_stride,
                            int width, int height,
-                           uint8_t* dst, int dst_stride) {
+                           uint8_t* WEBP_RESTRICT dst, int dst_stride) {
   uint32_t alpha_mask = 0xff;
   int i, j;
 
@@ -309,9 +311,10 @@ static int DispatchAlpha_C(const uint8_t* alpha, int alpha_stride,
   return (alpha_mask != 0xff);
 }
 
-static void DispatchAlphaToGreen_C(const uint8_t* alpha, int alpha_stride,
-                                   int width, int height,
-                                   uint32_t* dst, int dst_stride) {
+static void DispatchAlphaToGreen_C(const uint8_t* WEBP_RESTRICT alpha,
+                                   int alpha_stride, int width, int height,
+                                   uint32_t* WEBP_RESTRICT dst,
+                                   int dst_stride) {
   int i, j;
   for (j = 0; j < height; ++j) {
     for (i = 0; i < width; ++i) {
@@ -322,9 +325,9 @@ static void DispatchAlphaToGreen_C(const uint8_t* alpha, int alpha_stride,
   }
 }
 
-static int ExtractAlpha_C(const uint8_t* argb, int argb_stride,
+static int ExtractAlpha_C(const uint8_t* WEBP_RESTRICT argb, int argb_stride,
                           int width, int height,
-                          uint8_t* alpha, int alpha_stride) {
+                          uint8_t* WEBP_RESTRICT alpha, int alpha_stride) {
   uint8_t alpha_mask = 0xff;
   int i, j;
 
@@ -340,7 +343,8 @@ static int ExtractAlpha_C(const uint8_t* argb, int argb_stride,
   return (alpha_mask == 0xff);
 }
 
-static void ExtractGreen_C(const uint32_t* argb, uint8_t* alpha, int size) {
+static void ExtractGreen_C(const uint32_t* WEBP_RESTRICT argb,
+                           uint8_t* WEBP_RESTRICT alpha, int size) {
   int i;
   for (i = 0; i < size; ++i) alpha[i] = argb[i] >> 8;
 }
@@ -359,6 +363,11 @@ static int HasAlpha32b_C(const uint8_t* src, int length) {
   return 0;
 }
 
+static void AlphaReplace_C(uint32_t* src, int length, uint32_t color) {
+  int x;
+  for (x = 0; x < length; ++x) if ((src[x] >> 24) == 0) src[x] = color;
+}
+
 //------------------------------------------------------------------------------
 // Simple channel manipulations.
 
@@ -367,8 +376,11 @@ static WEBP_INLINE uint32_t MakeARGB32(int a, int r, int g, int b) {
 }
 
 #ifdef WORDS_BIGENDIAN
-static void PackARGB_C(const uint8_t* a, const uint8_t* r, const uint8_t* g,
-                       const uint8_t* b, int len, uint32_t* out) {
+static void PackARGB_C(const uint8_t* WEBP_RESTRICT a,
+                       const uint8_t* WEBP_RESTRICT r,
+                       const uint8_t* WEBP_RESTRICT g,
+                       const uint8_t* WEBP_RESTRICT b,
+                       int len, uint32_t* WEBP_RESTRICT out) {
   int i;
   for (i = 0; i < len; ++i) {
     out[i] = MakeARGB32(a[4 * i], r[4 * i], g[4 * i], b[4 * i]);
@@ -376,8 +388,10 @@ static void PackARGB_C(const uint8_t* a, const uint8_t* r, const uint8_t* g,
 }
 #endif
 
-static void PackRGB_C(const uint8_t* r, const uint8_t* g, const uint8_t* b,
-                      int len, int step, uint32_t* out) {
+static void PackRGB_C(const uint8_t* WEBP_RESTRICT r,
+                      const uint8_t* WEBP_RESTRICT g,
+                      const uint8_t* WEBP_RESTRICT b,
+                      int len, int step, uint32_t* WEBP_RESTRICT out) {
   int i, offset = 0;
   for (i = 0; i < len; ++i) {
     out[i] = MakeARGB32(0xff, r[offset], g[offset], b[offset]);
@@ -387,19 +401,26 @@ static void PackRGB_C(const uint8_t* r, const uint8_t* g, const uint8_t* b,
 
 void (*WebPApplyAlphaMultiply)(uint8_t*, int, int, int, int);
 void (*WebPApplyAlphaMultiply4444)(uint8_t*, int, int, int);
-int (*WebPDispatchAlpha)(const uint8_t*, int, int, int, uint8_t*, int);
-void (*WebPDispatchAlphaToGreen)(const uint8_t*, int, int, int, uint32_t*, int);
-int (*WebPExtractAlpha)(const uint8_t*, int, int, int, uint8_t*, int);
-void (*WebPExtractGreen)(const uint32_t* argb, uint8_t* alpha, int size);
+int (*WebPDispatchAlpha)(const uint8_t* WEBP_RESTRICT, int, int, int,
+                         uint8_t* WEBP_RESTRICT, int);
+void (*WebPDispatchAlphaToGreen)(const uint8_t* WEBP_RESTRICT, int, int, int,
+                                 uint32_t* WEBP_RESTRICT, int);
+int (*WebPExtractAlpha)(const uint8_t* WEBP_RESTRICT, int, int, int,
+                        uint8_t* WEBP_RESTRICT, int);
+void (*WebPExtractGreen)(const uint32_t* WEBP_RESTRICT argb,
+                         uint8_t* WEBP_RESTRICT alpha, int size);
 #ifdef WORDS_BIGENDIAN
 void (*WebPPackARGB)(const uint8_t* a, const uint8_t* r, const uint8_t* g,
                      const uint8_t* b, int, uint32_t*);
 #endif
-void (*WebPPackRGB)(const uint8_t* r, const uint8_t* g, const uint8_t* b,
-                    int len, int step, uint32_t* out);
+void (*WebPPackRGB)(const uint8_t* WEBP_RESTRICT r,
+                    const uint8_t* WEBP_RESTRICT g,
+                    const uint8_t* WEBP_RESTRICT b,
+                    int len, int step, uint32_t* WEBP_RESTRICT out);
 
 int (*WebPHasAlpha8b)(const uint8_t* src, int length);
 int (*WebPHasAlpha32b)(const uint8_t* src, int length);
+void (*WebPAlphaReplace)(uint32_t* src, int length, uint32_t color);
 
 //------------------------------------------------------------------------------
 // Init function
@@ -428,13 +449,14 @@ WEBP_DSP_INIT_FUNC(WebPInitAlphaProcessing) {
 
   WebPHasAlpha8b = HasAlpha8b_C;
   WebPHasAlpha32b = HasAlpha32b_C;
+  WebPAlphaReplace = AlphaReplace_C;
 
   // If defined, use CPUInfo() to overwrite some pointers with faster versions.
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       WebPInitAlphaProcessingSSE2();
-#if defined(WEBP_USE_SSE41)
+#if defined(WEBP_HAVE_SSE41)
       if (VP8GetCPUInfo(kSSE4_1)) {
         WebPInitAlphaProcessingSSE41();
       }
@@ -448,7 +470,7 @@ WEBP_DSP_INIT_FUNC(WebPInitAlphaProcessing) {
 #endif
   }
 
-#if defined(WEBP_USE_NEON)
+#if defined(WEBP_HAVE_NEON)
   if (WEBP_NEON_OMIT_C_CODE ||
       (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) {
     WebPInitAlphaProcessingNEON();
@@ -469,4 +491,5 @@ WEBP_DSP_INIT_FUNC(WebPInitAlphaProcessing) {
   assert(WebPPackRGB != NULL);
   assert(WebPHasAlpha8b != NULL);
   assert(WebPHasAlpha32b != NULL);
+  assert(WebPAlphaReplace != NULL);
 }
diff --git a/thirdparty/libwebp/src/dsp/alpha_processing_neon.c b/thirdparty/libwebp/src/dsp/alpha_processing_neon.c
index 9d55421704..9e0ace9421 100644
--- a/thirdparty/libwebp/src/dsp/alpha_processing_neon.c
+++ b/thirdparty/libwebp/src/dsp/alpha_processing_neon.c
@@ -80,9 +80,9 @@ static void ApplyAlphaMultiply_NEON(uint8_t* rgba, int alpha_first,
 
 //------------------------------------------------------------------------------
 
-static int DispatchAlpha_NEON(const uint8_t* alpha, int alpha_stride,
-                              int width, int height,
-                              uint8_t* dst, int dst_stride) {
+static int DispatchAlpha_NEON(const uint8_t* WEBP_RESTRICT alpha,
+                              int alpha_stride, int width, int height,
+                              uint8_t* WEBP_RESTRICT dst, int dst_stride) {
   uint32_t alpha_mask = 0xffffffffu;
   uint8x8_t mask8 = vdup_n_u8(0xff);
   uint32_t tmp[2];
@@ -112,9 +112,10 @@ static int DispatchAlpha_NEON(const uint8_t* alpha, int alpha_stride,
   return (alpha_mask != 0xffffffffu);
 }
 
-static void DispatchAlphaToGreen_NEON(const uint8_t* alpha, int alpha_stride,
-                                      int width, int height,
-                                      uint32_t* dst, int dst_stride) {
+static void DispatchAlphaToGreen_NEON(const uint8_t* WEBP_RESTRICT alpha,
+                                      int alpha_stride, int width, int height,
+                                      uint32_t* WEBP_RESTRICT dst,
+                                      int dst_stride) {
   int i, j;
   uint8x8x4_t greens;   // leave A/R/B channels zero'd.
   greens.val[0] = vdup_n_u8(0);
@@ -131,9 +132,9 @@ static void DispatchAlphaToGreen_NEON(const uint8_t* alpha, int alpha_stride,
   }
 }
 
-static int ExtractAlpha_NEON(const uint8_t* argb, int argb_stride,
+static int ExtractAlpha_NEON(const uint8_t* WEBP_RESTRICT argb, int argb_stride,
                              int width, int height,
-                             uint8_t* alpha, int alpha_stride) {
+                             uint8_t* WEBP_RESTRICT alpha, int alpha_stride) {
   uint32_t alpha_mask = 0xffffffffu;
   uint8x8_t mask8 = vdup_n_u8(0xff);
   uint32_t tmp[2];
@@ -161,8 +162,8 @@ static int ExtractAlpha_NEON(const uint8_t* argb, int argb_stride,
   return (alpha_mask == 0xffffffffu);
 }
 
-static void ExtractGreen_NEON(const uint32_t* argb,
-                              uint8_t* alpha, int size) {
+static void ExtractGreen_NEON(const uint32_t* WEBP_RESTRICT argb,
+                              uint8_t* WEBP_RESTRICT alpha, int size) {
   int i;
   for (i = 0; i + 16 <= size; i += 16) {
     const uint8x16x4_t rgbX = vld4q_u8((const uint8_t*)(argb + i));
diff --git a/thirdparty/libwebp/src/dsp/alpha_processing_sse2.c b/thirdparty/libwebp/src/dsp/alpha_processing_sse2.c
index 2871c56d84..a5f8c9f7c7 100644
--- a/thirdparty/libwebp/src/dsp/alpha_processing_sse2.c
+++ b/thirdparty/libwebp/src/dsp/alpha_processing_sse2.c
@@ -18,9 +18,9 @@
 
 //------------------------------------------------------------------------------
 
-static int DispatchAlpha_SSE2(const uint8_t* alpha, int alpha_stride,
-                              int width, int height,
-                              uint8_t* dst, int dst_stride) {
+static int DispatchAlpha_SSE2(const uint8_t* WEBP_RESTRICT alpha,
+                              int alpha_stride, int width, int height,
+                              uint8_t* WEBP_RESTRICT dst, int dst_stride) {
   // alpha_and stores an 'and' operation of all the alpha[] values. The final
   // value is not 0xff if any of the alpha[] is not equal to 0xff.
   uint32_t alpha_and = 0xff;
@@ -72,9 +72,10 @@ static int DispatchAlpha_SSE2(const uint8_t* alpha, int alpha_stride,
   return (alpha_and != 0xff);
 }
 
-static void DispatchAlphaToGreen_SSE2(const uint8_t* alpha, int alpha_stride,
-                                      int width, int height,
-                                      uint32_t* dst, int dst_stride) {
+static void DispatchAlphaToGreen_SSE2(const uint8_t* WEBP_RESTRICT alpha,
+                                      int alpha_stride, int width, int height,
+                                      uint32_t* WEBP_RESTRICT dst,
+                                      int dst_stride) {
   int i, j;
   const __m128i zero = _mm_setzero_si128();
   const int limit = width & ~15;
@@ -98,9 +99,9 @@ static void DispatchAlphaToGreen_SSE2(const uint8_t* alpha, int alpha_stride,
   }
 }
 
-static int ExtractAlpha_SSE2(const uint8_t* argb, int argb_stride,
+static int ExtractAlpha_SSE2(const uint8_t* WEBP_RESTRICT argb, int argb_stride,
                              int width, int height,
-                             uint8_t* alpha, int alpha_stride) {
+                             uint8_t* WEBP_RESTRICT alpha, int alpha_stride) {
   // alpha_and stores an 'and' operation of all the alpha[] values. The final
   // value is not 0xff if any of the alpha[] is not equal to 0xff.
   uint32_t alpha_and = 0xff;
@@ -265,6 +266,27 @@ static int HasAlpha32b_SSE2(const uint8_t* src, int length) {
   return 0;
 }
 
+static void AlphaReplace_SSE2(uint32_t* src, int length, uint32_t color) {
+  const __m128i m_color = _mm_set1_epi32(color);
+  const __m128i zero = _mm_setzero_si128();
+  int i = 0;
+  for (; i + 8 <= length; i += 8) {
+    const __m128i a0 = _mm_loadu_si128((const __m128i*)(src + i + 0));
+    const __m128i a1 = _mm_loadu_si128((const __m128i*)(src + i + 4));
+    const __m128i b0 = _mm_srai_epi32(a0, 24);
+    const __m128i b1 = _mm_srai_epi32(a1, 24);
+    const __m128i c0 = _mm_cmpeq_epi32(b0, zero);
+    const __m128i c1 = _mm_cmpeq_epi32(b1, zero);
+    const __m128i d0 = _mm_and_si128(c0, m_color);
+    const __m128i d1 = _mm_and_si128(c1, m_color);
+    const __m128i e0 = _mm_andnot_si128(c0, a0);
+    const __m128i e1 = _mm_andnot_si128(c1, a1);
+    _mm_storeu_si128((__m128i*)(src + i + 0), _mm_or_si128(d0, e0));
+    _mm_storeu_si128((__m128i*)(src + i + 4), _mm_or_si128(d1, e1));
+  }
+  for (; i < length; ++i) if ((src[i] >> 24) == 0) src[i] = color;
+}
+
 // -----------------------------------------------------------------------------
 // Apply alpha value to rows
 
@@ -296,7 +318,8 @@ static void MultARGBRow_SSE2(uint32_t* const ptr, int width, int inverse) {
   if (width > 0) WebPMultARGBRow_C(ptr + x, width, inverse);
 }
 
-static void MultRow_SSE2(uint8_t* const ptr, const uint8_t* const alpha,
+static void MultRow_SSE2(uint8_t* WEBP_RESTRICT const ptr,
+                         const uint8_t* WEBP_RESTRICT const alpha,
                          int width, int inverse) {
   int x = 0;
   if (!inverse) {
@@ -334,6 +357,7 @@ WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessingSSE2(void) {
 
   WebPHasAlpha8b = HasAlpha8b_SSE2;
   WebPHasAlpha32b = HasAlpha32b_SSE2;
+  WebPAlphaReplace = AlphaReplace_SSE2;
 }
 
 #else  // !WEBP_USE_SSE2
diff --git a/thirdparty/libwebp/src/dsp/alpha_processing_sse41.c b/thirdparty/libwebp/src/dsp/alpha_processing_sse41.c
index 56040f9c88..cdf877ce49 100644
--- a/thirdparty/libwebp/src/dsp/alpha_processing_sse41.c
+++ b/thirdparty/libwebp/src/dsp/alpha_processing_sse41.c
@@ -19,9 +19,9 @@
 
 //------------------------------------------------------------------------------
 
-static int ExtractAlpha_SSE41(const uint8_t* argb, int argb_stride,
-                              int width, int height,
-                              uint8_t* alpha, int alpha_stride) {
+static int ExtractAlpha_SSE41(const uint8_t* WEBP_RESTRICT argb,
+                              int argb_stride, int width, int height,
+                              uint8_t* WEBP_RESTRICT alpha, int alpha_stride) {
   // alpha_and stores an 'and' operation of all the alpha[] values. The final
   // value is not 0xff if any of the alpha[] is not equal to 0xff.
   uint32_t alpha_and = 0xff;
diff --git a/thirdparty/libwebp/src/dsp/cost.c b/thirdparty/libwebp/src/dsp/cost.c
index cc681cdd4b..460ec4f2a7 100644
--- a/thirdparty/libwebp/src/dsp/cost.c
+++ b/thirdparty/libwebp/src/dsp/cost.c
@@ -395,12 +395,12 @@ WEBP_DSP_INIT_FUNC(VP8EncDspCostInit) {
       VP8EncDspCostInitMIPSdspR2();
     }
 #endif
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       VP8EncDspCostInitSSE2();
     }
 #endif
-#if defined(WEBP_USE_NEON)
+#if defined(WEBP_HAVE_NEON)
     if (VP8GetCPUInfo(kNEON)) {
       VP8EncDspCostInitNEON();
     }
diff --git a/thirdparty/libwebp/src/dsp/cpu.c b/thirdparty/libwebp/src/dsp/cpu.c
index 0fa5b6a5ce..3145e190a4 100644
--- a/thirdparty/libwebp/src/dsp/cpu.c
+++ b/thirdparty/libwebp/src/dsp/cpu.c
@@ -55,12 +55,18 @@ static WEBP_INLINE void GetCPUInfo(int cpu_info[4], int info_type) {
     : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
     : "a"(info_type), "c"(0));
 }
-#elif (defined(_M_X64) || defined(_M_IX86)) && \
-      defined(_MSC_FULL_VER) && _MSC_FULL_VER >= 150030729  // >= VS2008 SP1
+#elif defined(_MSC_VER) && (defined(_M_X64) || defined(_M_IX86))
+
+#if defined(_MSC_FULL_VER) && _MSC_FULL_VER >= 150030729  // >= VS2008 SP1
 #include <intrin.h>
 #define GetCPUInfo(info, type) __cpuidex(info, type, 0)  // set ecx=0
-#elif defined(WEBP_MSC_SSE2)
+#define WEBP_HAVE_MSC_CPUID
+#elif _MSC_VER > 1310
+#include <intrin.h>
 #define GetCPUInfo __cpuid
+#define WEBP_HAVE_MSC_CPUID
+#endif
+
 #endif
 
 // NaCl has no support for xgetbv or the raw opcode.
@@ -94,7 +100,7 @@ static WEBP_INLINE uint64_t xgetbv(void) {
 #define xgetbv() 0U  // no AVX for older x64 or unrecognized toolchains.
 #endif
 
-#if defined(__i386__) || defined(__x86_64__) || defined(WEBP_MSC_SSE2)
+#if defined(__i386__) || defined(__x86_64__) || defined(WEBP_HAVE_MSC_CPUID)
 
 // helper function for run-time detection of slow SSSE3 platforms
 static int CheckSlowModel(int info) {
@@ -179,9 +185,34 @@ static int AndroidCPUInfo(CPUFeature feature) {
   return 0;
 }
 VP8CPUInfo VP8GetCPUInfo = AndroidCPUInfo;
-#elif defined(WEBP_USE_NEON)
-// define a dummy function to enable turning off NEON at runtime by setting
-// VP8DecGetCPUInfo = NULL
+#elif defined(EMSCRIPTEN) // also needs to be before generic NEON test
+// Use compile flags as an indicator of SIMD support instead of a runtime check.
+static int wasmCPUInfo(CPUFeature feature) {
+  switch (feature) {
+#ifdef WEBP_HAVE_SSE2
+    case kSSE2:
+      return 1;
+#endif
+#ifdef WEBP_HAVE_SSE41
+    case kSSE3:
+    case kSlowSSSE3:
+    case kSSE4_1:
+      return 1;
+#endif
+#ifdef WEBP_HAVE_NEON
+    case kNEON:
+      return 1;
+#endif
+    default:
+      break;
+  }
+  return 0;
+}
+VP8CPUInfo VP8GetCPUInfo = wasmCPUInfo;
+#elif defined(WEBP_HAVE_NEON)
+// In most cases this function doesn't check for NEON support (it's assumed by
+// the configuration), but enables turning off NEON at runtime, for testing
+// purposes, by setting VP8DecGetCPUInfo = NULL.
 static int armCPUInfo(CPUFeature feature) {
   if (feature != kNEON) return 0;
 #if defined(__linux__) && defined(WEBP_HAVE_NEON_RTCD)
diff --git a/thirdparty/libwebp/src/dsp/dec.c b/thirdparty/libwebp/src/dsp/dec.c
index 1119842dd3..537c701282 100644
--- a/thirdparty/libwebp/src/dsp/dec.c
+++ b/thirdparty/libwebp/src/dsp/dec.c
@@ -807,10 +807,10 @@ WEBP_DSP_INIT_FUNC(VP8DspInit) {
 
   // If defined, use CPUInfo() to overwrite some pointers with faster versions.
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       VP8DspInitSSE2();
-#if defined(WEBP_USE_SSE41)
+#if defined(WEBP_HAVE_SSE41)
       if (VP8GetCPUInfo(kSSE4_1)) {
         VP8DspInitSSE41();
       }
@@ -834,7 +834,7 @@ WEBP_DSP_INIT_FUNC(VP8DspInit) {
 #endif
   }
 
-#if defined(WEBP_USE_NEON)
+#if defined(WEBP_HAVE_NEON)
   if (WEBP_NEON_OMIT_C_CODE ||
       (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) {
     VP8DspInitNEON();
diff --git a/thirdparty/libwebp/src/dsp/dec_neon.c b/thirdparty/libwebp/src/dsp/dec_neon.c
index 239ec4167e..fa851707e2 100644
--- a/thirdparty/libwebp/src/dsp/dec_neon.c
+++ b/thirdparty/libwebp/src/dsp/dec_neon.c
@@ -1283,12 +1283,12 @@ static void DC4_NEON(uint8_t* dst) {    // DC
   const uint8x8_t A = vld1_u8(dst - BPS);  // top row
   const uint16x4_t p0 = vpaddl_u8(A);  // cascading summation of the top
   const uint16x4_t p1 = vpadd_u16(p0, p0);
-  const uint16x8_t L0 = vmovl_u8(vld1_u8(dst + 0 * BPS - 1));
-  const uint16x8_t L1 = vmovl_u8(vld1_u8(dst + 1 * BPS - 1));
-  const uint16x8_t L2 = vmovl_u8(vld1_u8(dst + 2 * BPS - 1));
-  const uint16x8_t L3 = vmovl_u8(vld1_u8(dst + 3 * BPS - 1));
-  const uint16x8_t s0 = vaddq_u16(L0, L1);
-  const uint16x8_t s1 = vaddq_u16(L2, L3);
+  const uint8x8_t L0 = vld1_u8(dst + 0 * BPS - 1);
+  const uint8x8_t L1 = vld1_u8(dst + 1 * BPS - 1);
+  const uint8x8_t L2 = vld1_u8(dst + 2 * BPS - 1);
+  const uint8x8_t L3 = vld1_u8(dst + 3 * BPS - 1);
+  const uint16x8_t s0 = vaddl_u8(L0, L1);
+  const uint16x8_t s1 = vaddl_u8(L2, L3);
   const uint16x8_t s01 = vaddq_u16(s0, s1);
   const uint16x8_t sum = vaddq_u16(s01, vcombine_u16(p1, p1));
   const uint8x8_t dc0 = vrshrn_n_u16(sum, 3);  // (sum + 4) >> 3
@@ -1429,8 +1429,7 @@ static WEBP_INLINE void DC8_NEON(uint8_t* dst, int do_top, int do_left) {
   if (do_top) {
     const uint8x8_t A = vld1_u8(dst - BPS);  // top row
 #if defined(__aarch64__)
-    const uint16x8_t B = vmovl_u8(A);
-    const uint16_t p2 = vaddvq_u16(B);
+    const uint16_t p2 = vaddlv_u8(A);
     sum_top = vdupq_n_u16(p2);
 #else
     const uint16x4_t p0 = vpaddl_u8(A);  // cascading summation of the top
@@ -1441,18 +1440,18 @@ static WEBP_INLINE void DC8_NEON(uint8_t* dst, int do_top, int do_left) {
   }
 
   if (do_left) {
-    const uint16x8_t L0 = vmovl_u8(vld1_u8(dst + 0 * BPS - 1));
-    const uint16x8_t L1 = vmovl_u8(vld1_u8(dst + 1 * BPS - 1));
-    const uint16x8_t L2 = vmovl_u8(vld1_u8(dst + 2 * BPS - 1));
-    const uint16x8_t L3 = vmovl_u8(vld1_u8(dst + 3 * BPS - 1));
-    const uint16x8_t L4 = vmovl_u8(vld1_u8(dst + 4 * BPS - 1));
-    const uint16x8_t L5 = vmovl_u8(vld1_u8(dst + 5 * BPS - 1));
-    const uint16x8_t L6 = vmovl_u8(vld1_u8(dst + 6 * BPS - 1));
-    const uint16x8_t L7 = vmovl_u8(vld1_u8(dst + 7 * BPS - 1));
-    const uint16x8_t s0 = vaddq_u16(L0, L1);
-    const uint16x8_t s1 = vaddq_u16(L2, L3);
-    const uint16x8_t s2 = vaddq_u16(L4, L5);
-    const uint16x8_t s3 = vaddq_u16(L6, L7);
+    const uint8x8_t L0 = vld1_u8(dst + 0 * BPS - 1);
+    const uint8x8_t L1 = vld1_u8(dst + 1 * BPS - 1);
+    const uint8x8_t L2 = vld1_u8(dst + 2 * BPS - 1);
+    const uint8x8_t L3 = vld1_u8(dst + 3 * BPS - 1);
+    const uint8x8_t L4 = vld1_u8(dst + 4 * BPS - 1);
+    const uint8x8_t L5 = vld1_u8(dst + 5 * BPS - 1);
+    const uint8x8_t L6 = vld1_u8(dst + 6 * BPS - 1);
+    const uint8x8_t L7 = vld1_u8(dst + 7 * BPS - 1);
+    const uint16x8_t s0 = vaddl_u8(L0, L1);
+    const uint16x8_t s1 = vaddl_u8(L2, L3);
+    const uint16x8_t s2 = vaddl_u8(L4, L5);
+    const uint16x8_t s3 = vaddl_u8(L6, L7);
     const uint16x8_t s01 = vaddq_u16(s0, s1);
     const uint16x8_t s23 = vaddq_u16(s2, s3);
     sum_left = vaddq_u16(s01, s23);
@@ -1512,29 +1511,34 @@ static WEBP_INLINE void DC16_NEON(uint8_t* dst, int do_top, int do_left) {
 
   if (do_top) {
     const uint8x16_t A = vld1q_u8(dst - BPS);  // top row
+#if defined(__aarch64__)
+    const uint16_t p3 = vaddlvq_u8(A);
+    sum_top = vdupq_n_u16(p3);
+#else
     const uint16x8_t p0 = vpaddlq_u8(A);  // cascading summation of the top
     const uint16x4_t p1 = vadd_u16(vget_low_u16(p0), vget_high_u16(p0));
     const uint16x4_t p2 = vpadd_u16(p1, p1);
     const uint16x4_t p3 = vpadd_u16(p2, p2);
     sum_top = vcombine_u16(p3, p3);
+#endif
   }
 
   if (do_left) {
     int i;
     sum_left = vdupq_n_u16(0);
     for (i = 0; i < 16; i += 8) {
-      const uint16x8_t L0 = vmovl_u8(vld1_u8(dst + (i + 0) * BPS - 1));
-      const uint16x8_t L1 = vmovl_u8(vld1_u8(dst + (i + 1) * BPS - 1));
-      const uint16x8_t L2 = vmovl_u8(vld1_u8(dst + (i + 2) * BPS - 1));
-      const uint16x8_t L3 = vmovl_u8(vld1_u8(dst + (i + 3) * BPS - 1));
-      const uint16x8_t L4 = vmovl_u8(vld1_u8(dst + (i + 4) * BPS - 1));
-      const uint16x8_t L5 = vmovl_u8(vld1_u8(dst + (i + 5) * BPS - 1));
-      const uint16x8_t L6 = vmovl_u8(vld1_u8(dst + (i + 6) * BPS - 1));
-      const uint16x8_t L7 = vmovl_u8(vld1_u8(dst + (i + 7) * BPS - 1));
-      const uint16x8_t s0 = vaddq_u16(L0, L1);
-      const uint16x8_t s1 = vaddq_u16(L2, L3);
-      const uint16x8_t s2 = vaddq_u16(L4, L5);
-      const uint16x8_t s3 = vaddq_u16(L6, L7);
+      const uint8x8_t L0 = vld1_u8(dst + (i + 0) * BPS - 1);
+      const uint8x8_t L1 = vld1_u8(dst + (i + 1) * BPS - 1);
+      const uint8x8_t L2 = vld1_u8(dst + (i + 2) * BPS - 1);
+      const uint8x8_t L3 = vld1_u8(dst + (i + 3) * BPS - 1);
+      const uint8x8_t L4 = vld1_u8(dst + (i + 4) * BPS - 1);
+      const uint8x8_t L5 = vld1_u8(dst + (i + 5) * BPS - 1);
+      const uint8x8_t L6 = vld1_u8(dst + (i + 6) * BPS - 1);
+      const uint8x8_t L7 = vld1_u8(dst + (i + 7) * BPS - 1);
+      const uint16x8_t s0 = vaddl_u8(L0, L1);
+      const uint16x8_t s1 = vaddl_u8(L2, L3);
+      const uint16x8_t s2 = vaddl_u8(L4, L5);
+      const uint16x8_t s3 = vaddl_u8(L6, L7);
       const uint16x8_t s01 = vaddq_u16(s0, s1);
       const uint16x8_t s23 = vaddq_u16(s2, s3);
       const uint16x8_t sum = vaddq_u16(s01, s23);
diff --git a/thirdparty/libwebp/src/dsp/dsp.h b/thirdparty/libwebp/src/dsp/dsp.h
index a784de334a..513e159bb3 100644
--- a/thirdparty/libwebp/src/dsp/dsp.h
+++ b/thirdparty/libwebp/src/dsp/dsp.h
@@ -27,6 +27,23 @@ extern "C" {
 #define BPS 32   // this is the common stride for enc/dec
 
 //------------------------------------------------------------------------------
+// WEBP_RESTRICT
+
+// Declares a pointer with the restrict type qualifier if available.
+// This allows code to hint to the compiler that only this pointer references a
+// particular object or memory region within the scope of the block in which it
+// is declared. This may allow for improved optimizations due to the lack of
+// pointer aliasing. See also:
+// https://en.cppreference.com/w/c/language/restrict
+#if defined(__GNUC__)
+#define WEBP_RESTRICT __restrict__
+#elif defined(_MSC_VER)
+#define WEBP_RESTRICT __restrict
+#else
+#define WEBP_RESTRICT
+#endif
+
+//------------------------------------------------------------------------------
 // CPU detection
 
 #if defined(__GNUC__)
@@ -51,9 +68,7 @@ extern "C" {
 # define __has_builtin(x) 0
 #endif
 
-// for now, none of the optimizations below are available in emscripten
-#if !defined(EMSCRIPTEN)
-
+#if !defined(HAVE_CONFIG_H)
 #if defined(_MSC_VER) && _MSC_VER > 1310 && \
     (defined(_M_X64) || defined(_M_IX86))
 #define WEBP_MSC_SSE2  // Visual C++ SSE2 targets
@@ -63,23 +78,37 @@ extern "C" {
     (defined(_M_X64) || defined(_M_IX86))
 #define WEBP_MSC_SSE41  // Visual C++ SSE4.1 targets
 #endif
+#endif
 
 // WEBP_HAVE_* are used to indicate the presence of the instruction set in dsp
 // files without intrinsics, allowing the corresponding Init() to be called.
 // Files containing intrinsics will need to be built targeting the instruction
 // set so should succeed on one of the earlier tests.
-#if defined(__SSE2__) || defined(WEBP_MSC_SSE2) || defined(WEBP_HAVE_SSE2)
+#if (defined(__SSE2__) || defined(WEBP_MSC_SSE2)) && \
+    (!defined(HAVE_CONFIG_H) || defined(WEBP_HAVE_SSE2))
 #define WEBP_USE_SSE2
 #endif
 
-#if defined(__SSE4_1__) || defined(WEBP_MSC_SSE41) || defined(WEBP_HAVE_SSE41)
+#if defined(WEBP_USE_SSE2) && !defined(WEBP_HAVE_SSE2)
+#define WEBP_HAVE_SSE2
+#endif
+
+#if (defined(__SSE4_1__) || defined(WEBP_MSC_SSE41)) && \
+    (!defined(HAVE_CONFIG_H) || defined(WEBP_HAVE_SSE41))
 #define WEBP_USE_SSE41
 #endif
 
+#if defined(WEBP_USE_SSE41) && !defined(WEBP_HAVE_SSE41)
+#define WEBP_HAVE_SSE41
+#endif
+
+#undef WEBP_MSC_SSE41
+#undef WEBP_MSC_SSE2
+
 // The intrinsics currently cause compiler errors with arm-nacl-gcc and the
 // inline assembly would need to be modified for use with Native Client.
-#if (defined(__ARM_NEON__) || \
-     defined(__aarch64__) || defined(WEBP_HAVE_NEON)) && \
+#if ((defined(__ARM_NEON__) || defined(__aarch64__)) && \
+     (!defined(HAVE_CONFIG_H) || defined(WEBP_HAVE_NEON))) && \
     !defined(__native_client__)
 #define WEBP_USE_NEON
 #endif
@@ -95,6 +124,10 @@ extern "C" {
 #define WEBP_USE_INTRINSICS
 #endif
 
+#if defined(WEBP_USE_NEON) && !defined(WEBP_HAVE_NEON)
+#define WEBP_HAVE_NEON
+#endif
+
 #if defined(__mips__) && !defined(__mips64) && \
     defined(__mips_isa_rev) && (__mips_isa_rev >= 1) && (__mips_isa_rev < 6)
 #define WEBP_USE_MIPS32
@@ -110,13 +143,11 @@ extern "C" {
 #define WEBP_USE_MSA
 #endif
 
-#endif  /* EMSCRIPTEN */
-
 #ifndef WEBP_DSP_OMIT_C_CODE
 #define WEBP_DSP_OMIT_C_CODE 1
 #endif
 
-#if (defined(__aarch64__) || defined(__ARM_NEON__)) && WEBP_DSP_OMIT_C_CODE
+#if defined(WEBP_USE_NEON) && WEBP_DSP_OMIT_C_CODE
 #define WEBP_NEON_OMIT_C_CODE 1
 #else
 #define WEBP_NEON_OMIT_C_CODE 0
@@ -193,6 +224,12 @@ extern "C" {
 #endif
 #endif
 
+// If 'ptr' is NULL, returns NULL. Otherwise returns 'ptr + off'.
+// Prevents undefined behavior sanitizer nullptr-with-nonzero-offset warning.
+#if !defined(WEBP_OFFSET_PTR)
+#define WEBP_OFFSET_PTR(ptr, off) (((ptr) == NULL) ? NULL : ((ptr) + (off)))
+#endif
+
 // Regularize the definition of WEBP_SWAP_16BIT_CSP (backward compatibility)
 #if !defined(WEBP_SWAP_16BIT_CSP)
 #define WEBP_SWAP_16BIT_CSP 0
@@ -572,26 +609,29 @@ extern void (*WebPApplyAlphaMultiply4444)(
 
 // Dispatch the values from alpha[] plane to the ARGB destination 'dst'.
 // Returns true if alpha[] plane has non-trivial values different from 0xff.
-extern int (*WebPDispatchAlpha)(const uint8_t* alpha, int alpha_stride,
-                                int width, int height,
-                                uint8_t* dst, int dst_stride);
+extern int (*WebPDispatchAlpha)(const uint8_t* WEBP_RESTRICT alpha,
+                                int alpha_stride, int width, int height,
+                                uint8_t* WEBP_RESTRICT dst, int dst_stride);
 
 // Transfer packed 8b alpha[] values to green channel in dst[], zero'ing the
 // A/R/B values. 'dst_stride' is the stride for dst[] in uint32_t units.
-extern void (*WebPDispatchAlphaToGreen)(const uint8_t* alpha, int alpha_stride,
-                                        int width, int height,
-                                        uint32_t* dst, int dst_stride);
+extern void (*WebPDispatchAlphaToGreen)(const uint8_t* WEBP_RESTRICT alpha,
+                                        int alpha_stride, int width, int height,
+                                        uint32_t* WEBP_RESTRICT dst,
+                                        int dst_stride);
 
 // Extract the alpha values from 32b values in argb[] and pack them into alpha[]
 // (this is the opposite of WebPDispatchAlpha).
 // Returns true if there's only trivial 0xff alpha values.
-extern int (*WebPExtractAlpha)(const uint8_t* argb, int argb_stride,
-                               int width, int height,
-                               uint8_t* alpha, int alpha_stride);
+extern int (*WebPExtractAlpha)(const uint8_t* WEBP_RESTRICT argb,
+                               int argb_stride, int width, int height,
+                               uint8_t* WEBP_RESTRICT alpha,
+                               int alpha_stride);
 
 // Extract the green values from 32b values in argb[] and pack them into alpha[]
 // (this is the opposite of WebPDispatchAlphaToGreen).
-extern void (*WebPExtractGreen)(const uint32_t* argb, uint8_t* alpha, int size);
+extern void (*WebPExtractGreen)(const uint32_t* WEBP_RESTRICT argb,
+                                uint8_t* WEBP_RESTRICT alpha, int size);
 
 // Pre-Multiply operation transforms x into x * A / 255  (where x=Y,R,G or B).
 // Un-Multiply operation transforms x into x * 255 / A.
@@ -604,34 +644,42 @@ void WebPMultARGBRows(uint8_t* ptr, int stride, int width, int num_rows,
                       int inverse);
 
 // Same for a row of single values, with side alpha values.
-extern void (*WebPMultRow)(uint8_t* const ptr, const uint8_t* const alpha,
+extern void (*WebPMultRow)(uint8_t* WEBP_RESTRICT const ptr,
+                           const uint8_t* WEBP_RESTRICT const alpha,
                            int width, int inverse);
 
 // Same a WebPMultRow(), but for several 'num_rows' rows.
-void WebPMultRows(uint8_t* ptr, int stride,
-                  const uint8_t* alpha, int alpha_stride,
+void WebPMultRows(uint8_t* WEBP_RESTRICT ptr, int stride,
+                  const uint8_t* WEBP_RESTRICT alpha, int alpha_stride,
                   int width, int num_rows, int inverse);
 
 // Plain-C versions, used as fallback by some implementations.
-void WebPMultRow_C(uint8_t* const ptr, const uint8_t* const alpha,
+void WebPMultRow_C(uint8_t* WEBP_RESTRICT const ptr,
+                   const uint8_t* WEBP_RESTRICT const alpha,
                    int width, int inverse);
 void WebPMultARGBRow_C(uint32_t* const ptr, int width, int inverse);
 
 #ifdef WORDS_BIGENDIAN
 // ARGB packing function: a/r/g/b input is rgba or bgra order.
-extern void (*WebPPackARGB)(const uint8_t* a, const uint8_t* r,
-                            const uint8_t* g, const uint8_t* b, int len,
-                            uint32_t* out);
+extern void (*WebPPackARGB)(const uint8_t* WEBP_RESTRICT a,
+                            const uint8_t* WEBP_RESTRICT r,
+                            const uint8_t* WEBP_RESTRICT g,
+                            const uint8_t* WEBP_RESTRICT b,
+                            int len, uint32_t* WEBP_RESTRICT out);
 #endif
 
 // RGB packing function. 'step' can be 3 or 4. r/g/b input is rgb or bgr order.
-extern void (*WebPPackRGB)(const uint8_t* r, const uint8_t* g, const uint8_t* b,
-                           int len, int step, uint32_t* out);
+extern void (*WebPPackRGB)(const uint8_t* WEBP_RESTRICT r,
+                           const uint8_t* WEBP_RESTRICT g,
+                           const uint8_t* WEBP_RESTRICT b,
+                           int len, int step, uint32_t* WEBP_RESTRICT out);
 
 // This function returns true if src[i] contains a value different from 0xff.
 extern int (*WebPHasAlpha8b)(const uint8_t* src, int length);
 // This function returns true if src[4*i] contains a value different from 0xff.
 extern int (*WebPHasAlpha32b)(const uint8_t* src, int length);
+// replaces transparent values in src[] by 'color'.
+extern void (*WebPAlphaReplace)(uint32_t* src, int length, uint32_t color);
 
 // To be called first before using the above.
 void WebPInitAlphaProcessing(void);
diff --git a/thirdparty/libwebp/src/dsp/enc.c b/thirdparty/libwebp/src/dsp/enc.c
index 2fddbc4c52..ea47a3fd95 100644
--- a/thirdparty/libwebp/src/dsp/enc.c
+++ b/thirdparty/libwebp/src/dsp/enc.c
@@ -773,10 +773,10 @@ WEBP_DSP_INIT_FUNC(VP8EncDspInit) {
 
   // If defined, use CPUInfo() to overwrite some pointers with faster versions.
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       VP8EncDspInitSSE2();
-#if defined(WEBP_USE_SSE41)
+#if defined(WEBP_HAVE_SSE41)
       if (VP8GetCPUInfo(kSSE4_1)) {
         VP8EncDspInitSSE41();
       }
@@ -800,7 +800,7 @@ WEBP_DSP_INIT_FUNC(VP8EncDspInit) {
 #endif
   }
 
-#if defined(WEBP_USE_NEON)
+#if defined(WEBP_HAVE_NEON)
   if (WEBP_NEON_OMIT_C_CODE ||
       (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) {
     VP8EncDspInitNEON();
diff --git a/thirdparty/libwebp/src/dsp/filters.c b/thirdparty/libwebp/src/dsp/filters.c
index 9e910d99c9..4506567ba3 100644
--- a/thirdparty/libwebp/src/dsp/filters.c
+++ b/thirdparty/libwebp/src/dsp/filters.c
@@ -254,7 +254,7 @@ WEBP_DSP_INIT_FUNC(VP8FiltersInit) {
 #endif
 
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       VP8FiltersInitSSE2();
     }
@@ -271,7 +271,7 @@ WEBP_DSP_INIT_FUNC(VP8FiltersInit) {
 #endif
   }
 
-#if defined(WEBP_USE_NEON)
+#if defined(WEBP_HAVE_NEON)
   if (WEBP_NEON_OMIT_C_CODE ||
       (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) {
     VP8FiltersInitNEON();
diff --git a/thirdparty/libwebp/src/dsp/filters_sse2.c b/thirdparty/libwebp/src/dsp/filters_sse2.c
index 4b3f2d020f..5c33ec15e2 100644
--- a/thirdparty/libwebp/src/dsp/filters_sse2.c
+++ b/thirdparty/libwebp/src/dsp/filters_sse2.c
@@ -320,7 +320,12 @@ extern void VP8FiltersInitSSE2(void);
 
 WEBP_TSAN_IGNORE_FUNCTION void VP8FiltersInitSSE2(void) {
   WebPUnfilters[WEBP_FILTER_HORIZONTAL] = HorizontalUnfilter_SSE2;
+#if defined(CHROMIUM)
+  // TODO(crbug.com/654974)
+  (void)VerticalUnfilter_SSE2;
+#else
   WebPUnfilters[WEBP_FILTER_VERTICAL] = VerticalUnfilter_SSE2;
+#endif
   WebPUnfilters[WEBP_FILTER_GRADIENT] = GradientUnfilter_SSE2;
 
   WebPFilters[WEBP_FILTER_HORIZONTAL] = HorizontalFilter_SSE2;
diff --git a/thirdparty/libwebp/src/dsp/lossless.c b/thirdparty/libwebp/src/dsp/lossless.c
index aad5f43ec9..d8bbb02b35 100644
--- a/thirdparty/libwebp/src/dsp/lossless.c
+++ b/thirdparty/libwebp/src/dsp/lossless.c
@@ -107,62 +107,62 @@ static WEBP_INLINE uint32_t Select(uint32_t a, uint32_t b, uint32_t c) {
 //------------------------------------------------------------------------------
 // Predictors
 
-static uint32_t Predictor0_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor0_C(uint32_t left, const uint32_t* const top) {
   (void)top;
   (void)left;
   return ARGB_BLACK;
 }
-static uint32_t Predictor1_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor1_C(uint32_t left, const uint32_t* const top) {
   (void)top;
   return left;
 }
-static uint32_t Predictor2_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor2_C(uint32_t left, const uint32_t* const top) {
   (void)left;
   return top[0];
 }
-static uint32_t Predictor3_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor3_C(uint32_t left, const uint32_t* const top) {
   (void)left;
   return top[1];
 }
-static uint32_t Predictor4_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor4_C(uint32_t left, const uint32_t* const top) {
   (void)left;
   return top[-1];
 }
-static uint32_t Predictor5_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor5_C(uint32_t left, const uint32_t* const top) {
   const uint32_t pred = Average3(left, top[0], top[1]);
   return pred;
 }
-static uint32_t Predictor6_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor6_C(uint32_t left, const uint32_t* const top) {
   const uint32_t pred = Average2(left, top[-1]);
   return pred;
 }
-static uint32_t Predictor7_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor7_C(uint32_t left, const uint32_t* const top) {
   const uint32_t pred = Average2(left, top[0]);
   return pred;
 }
-static uint32_t Predictor8_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor8_C(uint32_t left, const uint32_t* const top) {
   const uint32_t pred = Average2(top[-1], top[0]);
   (void)left;
   return pred;
 }
-static uint32_t Predictor9_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor9_C(uint32_t left, const uint32_t* const top) {
   const uint32_t pred = Average2(top[0], top[1]);
   (void)left;
   return pred;
 }
-static uint32_t Predictor10_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor10_C(uint32_t left, const uint32_t* const top) {
   const uint32_t pred = Average4(left, top[-1], top[0], top[1]);
   return pred;
 }
-static uint32_t Predictor11_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor11_C(uint32_t left, const uint32_t* const top) {
   const uint32_t pred = Select(top[0], left, top[-1]);
   return pred;
 }
-static uint32_t Predictor12_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor12_C(uint32_t left, const uint32_t* const top) {
   const uint32_t pred = ClampedAddSubtractFull(left, top[0], top[-1]);
   return pred;
 }
-static uint32_t Predictor13_C(uint32_t left, const uint32_t* const top) {
+uint32_t VP8LPredictor13_C(uint32_t left, const uint32_t* const top) {
   const uint32_t pred = ClampedAddSubtractHalf(left, top[0], top[-1]);
   return pred;
 }
@@ -182,18 +182,18 @@ static void PredictorAdd1_C(const uint32_t* in, const uint32_t* upper,
     out[i] = left = VP8LAddPixels(in[i], left);
   }
 }
-GENERATE_PREDICTOR_ADD(Predictor2_C, PredictorAdd2_C)
-GENERATE_PREDICTOR_ADD(Predictor3_C, PredictorAdd3_C)
-GENERATE_PREDICTOR_ADD(Predictor4_C, PredictorAdd4_C)
-GENERATE_PREDICTOR_ADD(Predictor5_C, PredictorAdd5_C)
-GENERATE_PREDICTOR_ADD(Predictor6_C, PredictorAdd6_C)
-GENERATE_PREDICTOR_ADD(Predictor7_C, PredictorAdd7_C)
-GENERATE_PREDICTOR_ADD(Predictor8_C, PredictorAdd8_C)
-GENERATE_PREDICTOR_ADD(Predictor9_C, PredictorAdd9_C)
-GENERATE_PREDICTOR_ADD(Predictor10_C, PredictorAdd10_C)
-GENERATE_PREDICTOR_ADD(Predictor11_C, PredictorAdd11_C)
-GENERATE_PREDICTOR_ADD(Predictor12_C, PredictorAdd12_C)
-GENERATE_PREDICTOR_ADD(Predictor13_C, PredictorAdd13_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor2_C, PredictorAdd2_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor3_C, PredictorAdd3_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor4_C, PredictorAdd4_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor5_C, PredictorAdd5_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor6_C, PredictorAdd6_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor7_C, PredictorAdd7_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor8_C, PredictorAdd8_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor9_C, PredictorAdd9_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor10_C, PredictorAdd10_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor11_C, PredictorAdd11_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor12_C, PredictorAdd12_C)
+GENERATE_PREDICTOR_ADD(VP8LPredictor13_C, PredictorAdd13_C)
 
 //------------------------------------------------------------------------------
 
@@ -562,7 +562,6 @@ VP8LPredictorFunc VP8LPredictors[16];
 
 // exposed plain-C implementations
 VP8LPredictorAddSubFunc VP8LPredictorsAdd_C[16];
-VP8LPredictorFunc VP8LPredictors_C[16];
 
 VP8LTransformColorInverseFunc VP8LTransformColorInverse;
 
@@ -576,6 +575,7 @@ VP8LMapARGBFunc VP8LMapColor32b;
 VP8LMapAlphaFunc VP8LMapColor8b;
 
 extern void VP8LDspInitSSE2(void);
+extern void VP8LDspInitSSE41(void);
 extern void VP8LDspInitNEON(void);
 extern void VP8LDspInitMIPSdspR2(void);
 extern void VP8LDspInitMSA(void);
@@ -600,8 +600,7 @@ extern void VP8LDspInitMSA(void);
 } while (0);
 
 WEBP_DSP_INIT_FUNC(VP8LDspInit) {
-  COPY_PREDICTOR_ARRAY(Predictor, VP8LPredictors)
-  COPY_PREDICTOR_ARRAY(Predictor, VP8LPredictors_C)
+  COPY_PREDICTOR_ARRAY(VP8LPredictor, VP8LPredictors)
   COPY_PREDICTOR_ARRAY(PredictorAdd, VP8LPredictorsAdd)
   COPY_PREDICTOR_ARRAY(PredictorAdd, VP8LPredictorsAdd_C)
 
@@ -623,9 +622,14 @@ WEBP_DSP_INIT_FUNC(VP8LDspInit) {
 
   // If defined, use CPUInfo() to overwrite some pointers with faster versions.
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       VP8LDspInitSSE2();
+#if defined(WEBP_HAVE_SSE41)
+      if (VP8GetCPUInfo(kSSE4_1)) {
+        VP8LDspInitSSE41();
+      }
+#endif
     }
 #endif
 #if defined(WEBP_USE_MIPS_DSP_R2)
@@ -640,7 +644,7 @@ WEBP_DSP_INIT_FUNC(VP8LDspInit) {
 #endif
   }
 
-#if defined(WEBP_USE_NEON)
+#if defined(WEBP_HAVE_NEON)
   if (WEBP_NEON_OMIT_C_CODE ||
       (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) {
     VP8LDspInitNEON();
diff --git a/thirdparty/libwebp/src/dsp/lossless.h b/thirdparty/libwebp/src/dsp/lossless.h
index f709cc86b2..ebd316d1ed 100644
--- a/thirdparty/libwebp/src/dsp/lossless.h
+++ b/thirdparty/libwebp/src/dsp/lossless.h
@@ -30,7 +30,22 @@ extern "C" {
 
 typedef uint32_t (*VP8LPredictorFunc)(uint32_t left, const uint32_t* const top);
 extern VP8LPredictorFunc VP8LPredictors[16];
-extern VP8LPredictorFunc VP8LPredictors_C[16];
+
+uint32_t VP8LPredictor0_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor1_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor2_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor3_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor4_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor5_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor6_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor7_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor8_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor9_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor10_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor11_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor12_C(uint32_t left, const uint32_t* const top);
+uint32_t VP8LPredictor13_C(uint32_t left, const uint32_t* const top);
+
 // These Add/Sub function expects upper[-1] and out[-1] to be readable.
 typedef void (*VP8LPredictorAddSubFunc)(const uint32_t* in,
                                         const uint32_t* upper, int num_pixels,
diff --git a/thirdparty/libwebp/src/dsp/lossless_common.h b/thirdparty/libwebp/src/dsp/lossless_common.h
index 9c2ebe6809..96a106f9ee 100644
--- a/thirdparty/libwebp/src/dsp/lossless_common.h
+++ b/thirdparty/libwebp/src/dsp/lossless_common.h
@@ -184,19 +184,6 @@ static void PREDICTOR_ADD(const uint32_t* in, const uint32_t* upper, \
   }                                                                  \
 }
 
-// It subtracts the prediction from the input pixel and stores the residual
-// in the output pixel.
-#define GENERATE_PREDICTOR_SUB(PREDICTOR, PREDICTOR_SUB)             \
-static void PREDICTOR_SUB(const uint32_t* in, const uint32_t* upper, \
-                          int num_pixels, uint32_t* out) {           \
-  int x;                                                             \
-  assert(upper != NULL);                                             \
-  for (x = 0; x < num_pixels; ++x) {                                 \
-    const uint32_t pred = (PREDICTOR)(in[x - 1], upper + x);         \
-    out[x] = VP8LSubPixels(in[x], pred);                             \
-  }                                                                  \
-}
-
 #ifdef __cplusplus
 }    // extern "C"
 #endif
diff --git a/thirdparty/libwebp/src/dsp/lossless_enc.c b/thirdparty/libwebp/src/dsp/lossless_enc.c
index 9c36055afc..c3e8537ade 100644
--- a/thirdparty/libwebp/src/dsp/lossless_enc.c
+++ b/thirdparty/libwebp/src/dsp/lossless_enc.c
@@ -329,6 +329,15 @@ const uint8_t kPrefixEncodeExtraBitsValue[PREFIX_LOOKUP_IDX_MAX] = {
 static float FastSLog2Slow_C(uint32_t v) {
   assert(v >= LOG_LOOKUP_IDX_MAX);
   if (v < APPROX_LOG_WITH_CORRECTION_MAX) {
+#if !defined(WEBP_HAVE_SLOW_CLZ_CTZ)
+    // use clz if available
+    const int log_cnt = BitsLog2Floor(v) - 7;
+    const uint32_t y = 1 << log_cnt;
+    int correction = 0;
+    const float v_f = (float)v;
+    const uint32_t orig_v = v;
+    v >>= log_cnt;
+#else
     int log_cnt = 0;
     uint32_t y = 1;
     int correction = 0;
@@ -339,6 +348,7 @@ static float FastSLog2Slow_C(uint32_t v) {
       v = v >> 1;
       y = y << 1;
     } while (v >= LOG_LOOKUP_IDX_MAX);
+#endif
     // vf = (2^log_cnt) * Xf; where y = 2^log_cnt and Xf < 256
     // Xf = floor(Xf) * (1 + (v % y) / v)
     // log2(Xf) = log2(floor(Xf)) + log2(1 + (v % y) / v)
@@ -355,6 +365,14 @@ static float FastSLog2Slow_C(uint32_t v) {
 static float FastLog2Slow_C(uint32_t v) {
   assert(v >= LOG_LOOKUP_IDX_MAX);
   if (v < APPROX_LOG_WITH_CORRECTION_MAX) {
+#if !defined(WEBP_HAVE_SLOW_CLZ_CTZ)
+    // use clz if available
+    const int log_cnt = BitsLog2Floor(v) - 7;
+    const uint32_t y = 1 << log_cnt;
+    const uint32_t orig_v = v;
+    double log_2;
+    v >>= log_cnt;
+#else
     int log_cnt = 0;
     uint32_t y = 1;
     const uint32_t orig_v = v;
@@ -364,6 +382,7 @@ static float FastLog2Slow_C(uint32_t v) {
       v = v >> 1;
       y = y << 1;
     } while (v >= LOG_LOOKUP_IDX_MAX);
+#endif
     log_2 = kLog2Table[v] + log_cnt;
     if (orig_v >= APPROX_LOG_MAX) {
       // Since the division is still expensive, add this correction factor only
@@ -702,140 +721,6 @@ void VP8LHistogramAdd(const VP8LHistogram* const a,
 //------------------------------------------------------------------------------
 // Image transforms.
 
-static WEBP_INLINE uint32_t Average2(uint32_t a0, uint32_t a1) {
-  return (((a0 ^ a1) & 0xfefefefeu) >> 1) + (a0 & a1);
-}
-
-static WEBP_INLINE uint32_t Average3(uint32_t a0, uint32_t a1, uint32_t a2) {
-  return Average2(Average2(a0, a2), a1);
-}
-
-static WEBP_INLINE uint32_t Average4(uint32_t a0, uint32_t a1,
-                                     uint32_t a2, uint32_t a3) {
-  return Average2(Average2(a0, a1), Average2(a2, a3));
-}
-
-static WEBP_INLINE uint32_t Clip255(uint32_t a) {
-  if (a < 256) {
-    return a;
-  }
-  // return 0, when a is a negative integer.
-  // return 255, when a is positive.
-  return ~a >> 24;
-}
-
-static WEBP_INLINE int AddSubtractComponentFull(int a, int b, int c) {
-  return Clip255(a + b - c);
-}
-
-static WEBP_INLINE uint32_t ClampedAddSubtractFull(uint32_t c0, uint32_t c1,
-                                                   uint32_t c2) {
-  const int a = AddSubtractComponentFull(c0 >> 24, c1 >> 24, c2 >> 24);
-  const int r = AddSubtractComponentFull((c0 >> 16) & 0xff,
-                                         (c1 >> 16) & 0xff,
-                                         (c2 >> 16) & 0xff);
-  const int g = AddSubtractComponentFull((c0 >> 8) & 0xff,
-                                         (c1 >> 8) & 0xff,
-                                         (c2 >> 8) & 0xff);
-  const int b = AddSubtractComponentFull(c0 & 0xff, c1 & 0xff, c2 & 0xff);
-  return ((uint32_t)a << 24) | (r << 16) | (g << 8) | b;
-}
-
-static WEBP_INLINE int AddSubtractComponentHalf(int a, int b) {
-  return Clip255(a + (a - b) / 2);
-}
-
-static WEBP_INLINE uint32_t ClampedAddSubtractHalf(uint32_t c0, uint32_t c1,
-                                                   uint32_t c2) {
-  const uint32_t ave = Average2(c0, c1);
-  const int a = AddSubtractComponentHalf(ave >> 24, c2 >> 24);
-  const int r = AddSubtractComponentHalf((ave >> 16) & 0xff, (c2 >> 16) & 0xff);
-  const int g = AddSubtractComponentHalf((ave >> 8) & 0xff, (c2 >> 8) & 0xff);
-  const int b = AddSubtractComponentHalf((ave >> 0) & 0xff, (c2 >> 0) & 0xff);
-  return ((uint32_t)a << 24) | (r << 16) | (g << 8) | b;
-}
-
-// gcc-4.9 on ARM generates incorrect code in Select() when Sub3() is inlined.
-#if defined(__arm__) && \
-    (LOCAL_GCC_VERSION == 0x409 || LOCAL_GCC_VERSION == 0x408)
-# define LOCAL_INLINE __attribute__ ((noinline))
-#else
-# define LOCAL_INLINE WEBP_INLINE
-#endif
-
-static LOCAL_INLINE int Sub3(int a, int b, int c) {
-  const int pb = b - c;
-  const int pa = a - c;
-  return abs(pb) - abs(pa);
-}
-
-#undef LOCAL_INLINE
-
-static WEBP_INLINE uint32_t Select(uint32_t a, uint32_t b, uint32_t c) {
-  const int pa_minus_pb =
-      Sub3((a >> 24)       , (b >> 24)       , (c >> 24)       ) +
-      Sub3((a >> 16) & 0xff, (b >> 16) & 0xff, (c >> 16) & 0xff) +
-      Sub3((a >>  8) & 0xff, (b >>  8) & 0xff, (c >>  8) & 0xff) +
-      Sub3((a      ) & 0xff, (b      ) & 0xff, (c      ) & 0xff);
-  return (pa_minus_pb <= 0) ? a : b;
-}
-
-//------------------------------------------------------------------------------
-// Predictors
-
-static uint32_t Predictor2(uint32_t left, const uint32_t* const top) {
-  (void)left;
-  return top[0];
-}
-static uint32_t Predictor3(uint32_t left, const uint32_t* const top) {
-  (void)left;
-  return top[1];
-}
-static uint32_t Predictor4(uint32_t left, const uint32_t* const top) {
-  (void)left;
-  return top[-1];
-}
-static uint32_t Predictor5(uint32_t left, const uint32_t* const top) {
-  const uint32_t pred = Average3(left, top[0], top[1]);
-  return pred;
-}
-static uint32_t Predictor6(uint32_t left, const uint32_t* const top) {
-  const uint32_t pred = Average2(left, top[-1]);
-  return pred;
-}
-static uint32_t Predictor7(uint32_t left, const uint32_t* const top) {
-  const uint32_t pred = Average2(left, top[0]);
-  return pred;
-}
-static uint32_t Predictor8(uint32_t left, const uint32_t* const top) {
-  const uint32_t pred = Average2(top[-1], top[0]);
-  (void)left;
-  return pred;
-}
-static uint32_t Predictor9(uint32_t left, const uint32_t* const top) {
-  const uint32_t pred = Average2(top[0], top[1]);
-  (void)left;
-  return pred;
-}
-static uint32_t Predictor10(uint32_t left, const uint32_t* const top) {
-  const uint32_t pred = Average4(left, top[-1], top[0], top[1]);
-  return pred;
-}
-static uint32_t Predictor11(uint32_t left, const uint32_t* const top) {
-  const uint32_t pred = Select(top[0], left, top[-1]);
-  return pred;
-}
-static uint32_t Predictor12(uint32_t left, const uint32_t* const top) {
-  const uint32_t pred = ClampedAddSubtractFull(left, top[0], top[-1]);
-  return pred;
-}
-static uint32_t Predictor13(uint32_t left, const uint32_t* const top) {
-  const uint32_t pred = ClampedAddSubtractHalf(left, top[0], top[-1]);
-  return pred;
-}
-
-//------------------------------------------------------------------------------
-
 static void PredictorSub0_C(const uint32_t* in, const uint32_t* upper,
                             int num_pixels, uint32_t* out) {
   int i;
@@ -850,18 +735,33 @@ static void PredictorSub1_C(const uint32_t* in, const uint32_t* upper,
   (void)upper;
 }
 
-GENERATE_PREDICTOR_SUB(Predictor2, PredictorSub2_C)
-GENERATE_PREDICTOR_SUB(Predictor3, PredictorSub3_C)
-GENERATE_PREDICTOR_SUB(Predictor4, PredictorSub4_C)
-GENERATE_PREDICTOR_SUB(Predictor5, PredictorSub5_C)
-GENERATE_PREDICTOR_SUB(Predictor6, PredictorSub6_C)
-GENERATE_PREDICTOR_SUB(Predictor7, PredictorSub7_C)
-GENERATE_PREDICTOR_SUB(Predictor8, PredictorSub8_C)
-GENERATE_PREDICTOR_SUB(Predictor9, PredictorSub9_C)
-GENERATE_PREDICTOR_SUB(Predictor10, PredictorSub10_C)
-GENERATE_PREDICTOR_SUB(Predictor11, PredictorSub11_C)
-GENERATE_PREDICTOR_SUB(Predictor12, PredictorSub12_C)
-GENERATE_PREDICTOR_SUB(Predictor13, PredictorSub13_C)
+// It subtracts the prediction from the input pixel and stores the residual
+// in the output pixel.
+#define GENERATE_PREDICTOR_SUB(PREDICTOR_I)                                \
+static void PredictorSub##PREDICTOR_I##_C(const uint32_t* in,              \
+                                          const uint32_t* upper,           \
+                                          int num_pixels, uint32_t* out) { \
+  int x;                                                                   \
+  assert(upper != NULL);                                                   \
+  for (x = 0; x < num_pixels; ++x) {                                       \
+    const uint32_t pred =                                                  \
+        VP8LPredictor##PREDICTOR_I##_C(in[x - 1], upper + x);              \
+    out[x] = VP8LSubPixels(in[x], pred);                                   \
+  }                                                                        \
+}
+
+GENERATE_PREDICTOR_SUB(2)
+GENERATE_PREDICTOR_SUB(3)
+GENERATE_PREDICTOR_SUB(4)
+GENERATE_PREDICTOR_SUB(5)
+GENERATE_PREDICTOR_SUB(6)
+GENERATE_PREDICTOR_SUB(7)
+GENERATE_PREDICTOR_SUB(8)
+GENERATE_PREDICTOR_SUB(9)
+GENERATE_PREDICTOR_SUB(10)
+GENERATE_PREDICTOR_SUB(11)
+GENERATE_PREDICTOR_SUB(12)
+GENERATE_PREDICTOR_SUB(13)
 
 //------------------------------------------------------------------------------
 
@@ -962,10 +862,10 @@ WEBP_DSP_INIT_FUNC(VP8LEncDspInit) {
 
   // If defined, use CPUInfo() to overwrite some pointers with faster versions.
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       VP8LEncDspInitSSE2();
-#if defined(WEBP_USE_SSE41)
+#if defined(WEBP_HAVE_SSE41)
       if (VP8GetCPUInfo(kSSE4_1)) {
         VP8LEncDspInitSSE41();
       }
@@ -989,7 +889,7 @@ WEBP_DSP_INIT_FUNC(VP8LEncDspInit) {
 #endif
   }
 
-#if defined(WEBP_USE_NEON)
+#if defined(WEBP_HAVE_NEON)
   if (WEBP_NEON_OMIT_C_CODE ||
       (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) {
     VP8LEncDspInitNEON();
diff --git a/thirdparty/libwebp/src/dsp/lossless_enc_sse2.c b/thirdparty/libwebp/src/dsp/lossless_enc_sse2.c
index e676f6fdc9..b2f83b871c 100644
--- a/thirdparty/libwebp/src/dsp/lossless_enc_sse2.c
+++ b/thirdparty/libwebp/src/dsp/lossless_enc_sse2.c
@@ -232,76 +232,55 @@ static void AddVectorEq_SSE2(const uint32_t* a, uint32_t* out, int size) {
 //------------------------------------------------------------------------------
 // Entropy
 
-// Checks whether the X or Y contribution is worth computing and adding.
-// Used in loop unrolling.
-#define ANALYZE_X_OR_Y(x_or_y, j)                                           \
-  do {                                                                      \
-    if ((x_or_y)[i + (j)] != 0) retval -= VP8LFastSLog2((x_or_y)[i + (j)]); \
-  } while (0)
-
-// Checks whether the X + Y contribution is worth computing and adding.
-// Used in loop unrolling.
-#define ANALYZE_XY(j)                  \
-  do {                                 \
-    if (tmp[j] != 0) {                 \
-      retval -= VP8LFastSLog2(tmp[j]); \
-      ANALYZE_X_OR_Y(X, j);            \
-    }                                  \
-  } while (0)
+// TODO(https://crbug.com/webp/499): this function produces different results
+// from the C code due to use of double/float resulting in output differences
+// when compared to -noasm.
+#if !(defined(WEBP_HAVE_SLOW_CLZ_CTZ) || defined(__i386__) || defined(_M_IX86))
 
 static float CombinedShannonEntropy_SSE2(const int X[256], const int Y[256]) {
   int i;
   double retval = 0.;
-  int sumX, sumXY;
-  int32_t tmp[4];
-  __m128i zero = _mm_setzero_si128();
-  // Sums up X + Y, 4 ints at a time (and will merge it at the end for sumXY).
-  __m128i sumXY_128 = zero;
-  __m128i sumX_128 = zero;
-
-  for (i = 0; i < 256; i += 4) {
-    const __m128i x = _mm_loadu_si128((const __m128i*)(X + i));
-    const __m128i y = _mm_loadu_si128((const __m128i*)(Y + i));
-
-    // Check if any X is non-zero: this actually provides a speedup as X is
-    // usually sparse.
-    if (_mm_movemask_epi8(_mm_cmpeq_epi32(x, zero)) != 0xFFFF) {
-      const __m128i xy_128 = _mm_add_epi32(x, y);
-      sumXY_128 = _mm_add_epi32(sumXY_128, xy_128);
-
-      sumX_128 = _mm_add_epi32(sumX_128, x);
-
-      // Analyze the different X + Y.
-      _mm_storeu_si128((__m128i*)tmp, xy_128);
-
-      ANALYZE_XY(0);
-      ANALYZE_XY(1);
-      ANALYZE_XY(2);
-      ANALYZE_XY(3);
-    } else {
-      // X is fully 0, so only deal with Y.
-      sumXY_128 = _mm_add_epi32(sumXY_128, y);
-
-      ANALYZE_X_OR_Y(Y, 0);
-      ANALYZE_X_OR_Y(Y, 1);
-      ANALYZE_X_OR_Y(Y, 2);
-      ANALYZE_X_OR_Y(Y, 3);
+  int sumX = 0, sumXY = 0;
+  const __m128i zero = _mm_setzero_si128();
+
+  for (i = 0; i < 256; i += 16) {
+    const __m128i x0 = _mm_loadu_si128((const __m128i*)(X + i +  0));
+    const __m128i y0 = _mm_loadu_si128((const __m128i*)(Y + i +  0));
+    const __m128i x1 = _mm_loadu_si128((const __m128i*)(X + i +  4));
+    const __m128i y1 = _mm_loadu_si128((const __m128i*)(Y + i +  4));
+    const __m128i x2 = _mm_loadu_si128((const __m128i*)(X + i +  8));
+    const __m128i y2 = _mm_loadu_si128((const __m128i*)(Y + i +  8));
+    const __m128i x3 = _mm_loadu_si128((const __m128i*)(X + i + 12));
+    const __m128i y3 = _mm_loadu_si128((const __m128i*)(Y + i + 12));
+    const __m128i x4 = _mm_packs_epi16(_mm_packs_epi32(x0, x1),
+                                       _mm_packs_epi32(x2, x3));
+    const __m128i y4 = _mm_packs_epi16(_mm_packs_epi32(y0, y1),
+                                       _mm_packs_epi32(y2, y3));
+    const int32_t mx = _mm_movemask_epi8(_mm_cmpgt_epi8(x4, zero));
+    int32_t my = _mm_movemask_epi8(_mm_cmpgt_epi8(y4, zero)) | mx;
+    while (my) {
+      const int32_t j = BitsCtz(my);
+      int xy;
+      if ((mx >> j) & 1) {
+        const int x = X[i + j];
+        sumXY += x;
+        retval -= VP8LFastSLog2(x);
+      }
+      xy = X[i + j] + Y[i + j];
+      sumX += xy;
+      retval -= VP8LFastSLog2(xy);
+      my &= my - 1;
     }
   }
-
-  // Sum up sumX_128 to get sumX.
-  _mm_storeu_si128((__m128i*)tmp, sumX_128);
-  sumX = tmp[3] + tmp[2] + tmp[1] + tmp[0];
-
-  // Sum up sumXY_128 to get sumXY.
-  _mm_storeu_si128((__m128i*)tmp, sumXY_128);
-  sumXY = tmp[3] + tmp[2] + tmp[1] + tmp[0];
-
   retval += VP8LFastSLog2(sumX) + VP8LFastSLog2(sumXY);
   return (float)retval;
 }
-#undef ANALYZE_X_OR_Y
-#undef ANALYZE_XY
+
+#else
+
+#define DONT_USE_COMBINED_SHANNON_ENTROPY_SSE2_FUNC   // won't be faster
+
+#endif
 
 //------------------------------------------------------------------------------
 
@@ -460,20 +439,22 @@ static void PredictorSub0_SSE2(const uint32_t* in, const uint32_t* upper,
   (void)upper;
 }
 
-#define GENERATE_PREDICTOR_1(X, IN)                                           \
-static void PredictorSub##X##_SSE2(const uint32_t* in, const uint32_t* upper, \
-                                   int num_pixels, uint32_t* out) {           \
-  int i;                                                                      \
-  for (i = 0; i + 4 <= num_pixels; i += 4) {                                  \
-    const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);              \
-    const __m128i pred = _mm_loadu_si128((const __m128i*)&(IN));              \
-    const __m128i res = _mm_sub_epi8(src, pred);                              \
-    _mm_storeu_si128((__m128i*)&out[i], res);                                 \
-  }                                                                           \
-  if (i != num_pixels) {                                                      \
-    VP8LPredictorsSub_C[(X)](in + i, upper + i, num_pixels - i, out + i);     \
-  }                                                                           \
-}
+#define GENERATE_PREDICTOR_1(X, IN)                                         \
+  static void PredictorSub##X##_SSE2(const uint32_t* const in,              \
+                                     const uint32_t* const upper,           \
+                                     int num_pixels, uint32_t* const out) { \
+    int i;                                                                  \
+    for (i = 0; i + 4 <= num_pixels; i += 4) {                              \
+      const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);          \
+      const __m128i pred = _mm_loadu_si128((const __m128i*)&(IN));          \
+      const __m128i res = _mm_sub_epi8(src, pred);                          \
+      _mm_storeu_si128((__m128i*)&out[i], res);                             \
+    }                                                                       \
+    if (i != num_pixels) {                                                  \
+      VP8LPredictorsSub_C[(X)](in + i, WEBP_OFFSET_PTR(upper, i),           \
+                               num_pixels - i, out + i);                    \
+    }                                                                       \
+  }
 
 GENERATE_PREDICTOR_1(1, in[i - 1])       // Predictor1: L
 GENERATE_PREDICTOR_1(2, upper[i])        // Predictor2: T
@@ -657,7 +638,9 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8LEncDspInitSSE2(void) {
   VP8LCollectColorRedTransforms = CollectColorRedTransforms_SSE2;
   VP8LAddVector = AddVector_SSE2;
   VP8LAddVectorEq = AddVectorEq_SSE2;
+#if !defined(DONT_USE_COMBINED_SHANNON_ENTROPY_SSE2_FUNC)
   VP8LCombinedShannonEntropy = CombinedShannonEntropy_SSE2;
+#endif
   VP8LVectorMismatch = VectorMismatch_SSE2;
   VP8LBundleColorMap = BundleColorMap_SSE2;
 
diff --git a/thirdparty/libwebp/src/dsp/lossless_enc_sse41.c b/thirdparty/libwebp/src/dsp/lossless_enc_sse41.c
index 719d8ed25e..ad358a6f25 100644
--- a/thirdparty/libwebp/src/dsp/lossless_enc_sse41.c
+++ b/thirdparty/libwebp/src/dsp/lossless_enc_sse41.c
@@ -44,46 +44,47 @@ static void SubtractGreenFromBlueAndRed_SSE41(uint32_t* argb_data,
 //------------------------------------------------------------------------------
 // Color Transform
 
-#define SPAN 8
+#define MK_CST_16(HI, LO) \
+  _mm_set1_epi32((int)(((uint32_t)(HI) << 16) | ((LO) & 0xffff)))
+
 static void CollectColorBlueTransforms_SSE41(const uint32_t* argb, int stride,
                                              int tile_width, int tile_height,
                                              int green_to_blue, int red_to_blue,
                                              int histo[]) {
-  const __m128i mults_r = _mm_set1_epi16(CST_5b(red_to_blue));
-  const __m128i mults_g = _mm_set1_epi16(CST_5b(green_to_blue));
-  const __m128i mask_g = _mm_set1_epi16((short)0xff00);   // green mask
-  const __m128i mask_gb = _mm_set1_epi32(0xffff);         // green/blue mask
-  const __m128i mask_b = _mm_set1_epi16(0x00ff);          // blue mask
-  const __m128i shuffler_lo = _mm_setr_epi8(-1, 2, -1, 6, -1, 10, -1, 14, -1,
-                                            -1, -1, -1, -1, -1, -1, -1);
-  const __m128i shuffler_hi = _mm_setr_epi8(-1, -1, -1, -1, -1, -1, -1, -1, -1,
-                                            2, -1, 6, -1, 10, -1, 14);
-  int y;
-  for (y = 0; y < tile_height; ++y) {
-    const uint32_t* const src = argb + y * stride;
-    int i, x;
-    for (x = 0; x + SPAN <= tile_width; x += SPAN) {
-      uint16_t values[SPAN];
-      const __m128i in0 = _mm_loadu_si128((__m128i*)&src[x + 0]);
-      const __m128i in1 = _mm_loadu_si128((__m128i*)&src[x + SPAN / 2]);
-      const __m128i r0 = _mm_shuffle_epi8(in0, shuffler_lo);
-      const __m128i r1 = _mm_shuffle_epi8(in1, shuffler_hi);
-      const __m128i r = _mm_or_si128(r0, r1);         // r 0
-      const __m128i gb0 = _mm_and_si128(in0, mask_gb);
-      const __m128i gb1 = _mm_and_si128(in1, mask_gb);
-      const __m128i gb = _mm_packus_epi32(gb0, gb1);  // g b
-      const __m128i g = _mm_and_si128(gb, mask_g);    // g 0
-      const __m128i A = _mm_mulhi_epi16(r, mults_r);  // x dbr
-      const __m128i B = _mm_mulhi_epi16(g, mults_g);  // x dbg
-      const __m128i C = _mm_sub_epi8(gb, B);          // x b'
-      const __m128i D = _mm_sub_epi8(C, A);           // x b''
-      const __m128i E = _mm_and_si128(D, mask_b);     // 0 b''
-      _mm_storeu_si128((__m128i*)values, E);
-      for (i = 0; i < SPAN; ++i) ++histo[values[i]];
+  const __m128i mult =
+      MK_CST_16(CST_5b(red_to_blue) + 256,CST_5b(green_to_blue));
+  const __m128i perm =
+      _mm_setr_epi8(-1, 1, -1, 2, -1, 5, -1, 6, -1, 9, -1, 10, -1, 13, -1, 14);
+  if (tile_width >= 4) {
+    int y;
+    for (y = 0; y < tile_height; ++y) {
+      const uint32_t* const src = argb + y * stride;
+      const __m128i A1 = _mm_loadu_si128((const __m128i*)src);
+      const __m128i B1 = _mm_shuffle_epi8(A1, perm);
+      const __m128i C1 = _mm_mulhi_epi16(B1, mult);
+      const __m128i D1 = _mm_sub_epi16(A1, C1);
+      __m128i E = _mm_add_epi16(_mm_srli_epi32(D1, 16), D1);
+      int x;
+      for (x = 4; x + 4 <= tile_width; x += 4) {
+        const __m128i A2 = _mm_loadu_si128((const __m128i*)(src + x));
+        __m128i B2, C2, D2;
+        ++histo[_mm_extract_epi8(E,  0)];
+        B2 = _mm_shuffle_epi8(A2, perm);
+        ++histo[_mm_extract_epi8(E,  4)];
+        C2 = _mm_mulhi_epi16(B2, mult);
+        ++histo[_mm_extract_epi8(E,  8)];
+        D2 = _mm_sub_epi16(A2, C2);
+        ++histo[_mm_extract_epi8(E, 12)];
+        E = _mm_add_epi16(_mm_srli_epi32(D2, 16), D2);
+      }
+      ++histo[_mm_extract_epi8(E,  0)];
+      ++histo[_mm_extract_epi8(E,  4)];
+      ++histo[_mm_extract_epi8(E,  8)];
+      ++histo[_mm_extract_epi8(E, 12)];
     }
   }
   {
-    const int left_over = tile_width & (SPAN - 1);
+    const int left_over = tile_width & 3;
     if (left_over > 0) {
       VP8LCollectColorBlueTransforms_C(argb + tile_width - left_over, stride,
                                        left_over, tile_height,
@@ -95,33 +96,37 @@ static void CollectColorBlueTransforms_SSE41(const uint32_t* argb, int stride,
 static void CollectColorRedTransforms_SSE41(const uint32_t* argb, int stride,
                                             int tile_width, int tile_height,
                                             int green_to_red, int histo[]) {
-  const __m128i mults_g = _mm_set1_epi16(CST_5b(green_to_red));
-  const __m128i mask_g = _mm_set1_epi32(0x00ff00);  // green mask
-  const __m128i mask = _mm_set1_epi16(0xff);
-
-  int y;
-  for (y = 0; y < tile_height; ++y) {
-    const uint32_t* const src = argb + y * stride;
-    int i, x;
-    for (x = 0; x + SPAN <= tile_width; x += SPAN) {
-      uint16_t values[SPAN];
-      const __m128i in0 = _mm_loadu_si128((__m128i*)&src[x + 0]);
-      const __m128i in1 = _mm_loadu_si128((__m128i*)&src[x + SPAN / 2]);
-      const __m128i g0 = _mm_and_si128(in0, mask_g);  // 0 0  | g 0
-      const __m128i g1 = _mm_and_si128(in1, mask_g);
-      const __m128i g = _mm_packus_epi32(g0, g1);     // g 0
-      const __m128i A0 = _mm_srli_epi32(in0, 16);     // 0 0  | x r
-      const __m128i A1 = _mm_srli_epi32(in1, 16);
-      const __m128i A = _mm_packus_epi32(A0, A1);     // x r
-      const __m128i B = _mm_mulhi_epi16(g, mults_g);  // x dr
-      const __m128i C = _mm_sub_epi8(A, B);           // x r'
-      const __m128i D = _mm_and_si128(C, mask);       // 0 r'
-      _mm_storeu_si128((__m128i*)values, D);
-      for (i = 0; i < SPAN; ++i) ++histo[values[i]];
+
+  const __m128i mult = MK_CST_16(0, CST_5b(green_to_red));
+  const __m128i mask_g = _mm_set1_epi32(0x0000ff00);
+  if (tile_width >= 4) {
+    int y;
+    for (y = 0; y < tile_height; ++y) {
+      const uint32_t* const src = argb + y * stride;
+      const __m128i A1 = _mm_loadu_si128((const __m128i*)src);
+      const __m128i B1 = _mm_and_si128(A1, mask_g);
+      const __m128i C1 = _mm_madd_epi16(B1, mult);
+      __m128i D = _mm_sub_epi16(A1, C1);
+      int x;
+      for (x = 4; x + 4 <= tile_width; x += 4) {
+        const __m128i A2 = _mm_loadu_si128((const __m128i*)(src + x));
+        __m128i B2, C2;
+        ++histo[_mm_extract_epi8(D,  2)];
+        B2 = _mm_and_si128(A2, mask_g);
+        ++histo[_mm_extract_epi8(D,  6)];
+        C2 = _mm_madd_epi16(B2, mult);
+        ++histo[_mm_extract_epi8(D, 10)];
+        ++histo[_mm_extract_epi8(D, 14)];
+        D = _mm_sub_epi16(A2, C2);
+      }
+      ++histo[_mm_extract_epi8(D,  2)];
+      ++histo[_mm_extract_epi8(D,  6)];
+      ++histo[_mm_extract_epi8(D, 10)];
+      ++histo[_mm_extract_epi8(D, 14)];
     }
   }
   {
-    const int left_over = tile_width & (SPAN - 1);
+    const int left_over = tile_width & 3;
     if (left_over > 0) {
       VP8LCollectColorRedTransforms_C(argb + tile_width - left_over, stride,
                                       left_over, tile_height, green_to_red,
@@ -130,6 +135,8 @@ static void CollectColorRedTransforms_SSE41(const uint32_t* argb, int stride,
   }
 }
 
+#undef MK_CST_16
+
 //------------------------------------------------------------------------------
 // Entry point
 
diff --git a/thirdparty/libwebp/src/dsp/lossless_sse2.c b/thirdparty/libwebp/src/dsp/lossless_sse2.c
index aef0cee1b3..3a0eb440db 100644
--- a/thirdparty/libwebp/src/dsp/lossless_sse2.c
+++ b/thirdparty/libwebp/src/dsp/lossless_sse2.c
@@ -18,7 +18,6 @@
 #include "src/dsp/common_sse2.h"
 #include "src/dsp/lossless.h"
 #include "src/dsp/lossless_common.h"
-#include <assert.h>
 #include <emmintrin.h>
 
 //------------------------------------------------------------------------------
diff --git a/thirdparty/libwebp/src/dsp/lossless_sse41.c b/thirdparty/libwebp/src/dsp/lossless_sse41.c
new file mode 100644
index 0000000000..b0d6daa7fe
--- /dev/null
+++ b/thirdparty/libwebp/src/dsp/lossless_sse41.c
@@ -0,0 +1,132 @@
+// Copyright 2021 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// SSE41 variant of methods for lossless decoder
+
+#include "src/dsp/dsp.h"
+
+#if defined(WEBP_USE_SSE41)
+
+#include "src/dsp/common_sse41.h"
+#include "src/dsp/lossless.h"
+#include "src/dsp/lossless_common.h"
+
+//------------------------------------------------------------------------------
+// Color-space conversion functions
+
+static void TransformColorInverse_SSE41(const VP8LMultipliers* const m,
+                                        const uint32_t* const src,
+                                        int num_pixels, uint32_t* dst) {
+// sign-extended multiplying constants, pre-shifted by 5.
+#define CST(X)  (((int16_t)(m->X << 8)) >> 5)   // sign-extend
+  const __m128i mults_rb = _mm_set1_epi32((uint32_t)CST(green_to_red_) << 16 |
+                                          (CST(green_to_blue_) & 0xffff));
+  const __m128i mults_b2 = _mm_set1_epi32(CST(red_to_blue_));
+#undef CST
+  const __m128i mask_ag = _mm_set1_epi32(0xff00ff00);
+  const __m128i perm1 = _mm_setr_epi8(-1, 1, -1, 1, -1, 5, -1, 5,
+                                      -1, 9, -1, 9, -1, 13, -1, 13);
+  const __m128i perm2 = _mm_setr_epi8(-1, 2, -1, -1, -1, 6, -1, -1,
+                                      -1, 10, -1, -1, -1, 14, -1, -1);
+  int i;
+  for (i = 0; i + 4 <= num_pixels; i += 4) {
+    const __m128i A = _mm_loadu_si128((const __m128i*)(src + i));
+    const __m128i B = _mm_shuffle_epi8(A, perm1); // argb -> g0g0
+    const __m128i C = _mm_mulhi_epi16(B, mults_rb);
+    const __m128i D = _mm_add_epi8(A, C);
+    const __m128i E = _mm_shuffle_epi8(D, perm2);
+    const __m128i F = _mm_mulhi_epi16(E, mults_b2);
+    const __m128i G = _mm_add_epi8(D, F);
+    const __m128i out = _mm_blendv_epi8(G, A, mask_ag);
+    _mm_storeu_si128((__m128i*)&dst[i], out);
+  }
+  // Fall-back to C-version for left-overs.
+  if (i != num_pixels) {
+    VP8LTransformColorInverse_C(m, src + i, num_pixels - i, dst + i);
+  }
+}
+
+//------------------------------------------------------------------------------
+
+#define ARGB_TO_RGB_SSE41 do {                        \
+  while (num_pixels >= 16) {                          \
+    const __m128i in0 = _mm_loadu_si128(in + 0);      \
+    const __m128i in1 = _mm_loadu_si128(in + 1);      \
+    const __m128i in2 = _mm_loadu_si128(in + 2);      \
+    const __m128i in3 = _mm_loadu_si128(in + 3);      \
+    const __m128i a0 = _mm_shuffle_epi8(in0, perm0);  \
+    const __m128i a1 = _mm_shuffle_epi8(in1, perm1);  \
+    const __m128i a2 = _mm_shuffle_epi8(in2, perm2);  \
+    const __m128i a3 = _mm_shuffle_epi8(in3, perm3);  \
+    const __m128i b0 = _mm_blend_epi16(a0, a1, 0xc0); \
+    const __m128i b1 = _mm_blend_epi16(a1, a2, 0xf0); \
+    const __m128i b2 = _mm_blend_epi16(a2, a3, 0xfc); \
+    _mm_storeu_si128(out + 0, b0);                    \
+    _mm_storeu_si128(out + 1, b1);                    \
+    _mm_storeu_si128(out + 2, b2);                    \
+    in += 4;                                          \
+    out += 3;                                         \
+    num_pixels -= 16;                                 \
+  }                                                   \
+} while (0)
+
+static void ConvertBGRAToRGB_SSE41(const uint32_t* src, int num_pixels,
+                                   uint8_t* dst) {
+  const __m128i* in = (const __m128i*)src;
+  __m128i* out = (__m128i*)dst;
+  const __m128i perm0 = _mm_setr_epi8(2, 1, 0, 6, 5, 4, 10, 9,
+                                      8, 14, 13, 12, -1, -1, -1, -1);
+  const __m128i perm1 = _mm_shuffle_epi32(perm0, 0x39);
+  const __m128i perm2 = _mm_shuffle_epi32(perm0, 0x4e);
+  const __m128i perm3 = _mm_shuffle_epi32(perm0, 0x93);
+
+  ARGB_TO_RGB_SSE41;
+
+  // left-overs
+  if (num_pixels > 0) {
+    VP8LConvertBGRAToRGB_C((const uint32_t*)in, num_pixels, (uint8_t*)out);
+  }
+}
+
+static void ConvertBGRAToBGR_SSE41(const uint32_t* src,
+                                   int num_pixels, uint8_t* dst) {
+  const __m128i* in = (const __m128i*)src;
+  __m128i* out = (__m128i*)dst;
+  const __m128i perm0 = _mm_setr_epi8(0, 1, 2, 4, 5, 6, 8, 9, 10,
+                                      12, 13, 14, -1, -1, -1, -1);
+  const __m128i perm1 = _mm_shuffle_epi32(perm0, 0x39);
+  const __m128i perm2 = _mm_shuffle_epi32(perm0, 0x4e);
+  const __m128i perm3 = _mm_shuffle_epi32(perm0, 0x93);
+
+  ARGB_TO_RGB_SSE41;
+
+  // left-overs
+  if (num_pixels > 0) {
+    VP8LConvertBGRAToBGR_C((const uint32_t*)in, num_pixels, (uint8_t*)out);
+  }
+}
+
+#undef ARGB_TO_RGB_SSE41
+
+//------------------------------------------------------------------------------
+// Entry point
+
+extern void VP8LDspInitSSE41(void);
+
+WEBP_TSAN_IGNORE_FUNCTION void VP8LDspInitSSE41(void) {
+  VP8LTransformColorInverse = TransformColorInverse_SSE41;
+  VP8LConvertBGRAToRGB = ConvertBGRAToRGB_SSE41;
+  VP8LConvertBGRAToBGR = ConvertBGRAToBGR_SSE41;
+}
+
+#else  // !WEBP_USE_SSE41
+
+WEBP_DSP_INIT_STUB(VP8LDspInitSSE41)
+
+#endif  // WEBP_USE_SSE41
diff --git a/thirdparty/libwebp/src/dsp/rescaler.c b/thirdparty/libwebp/src/dsp/rescaler.c
index c5a01e82df..14620ce4f1 100644
--- a/thirdparty/libwebp/src/dsp/rescaler.c
+++ b/thirdparty/libwebp/src/dsp/rescaler.c
@@ -38,8 +38,9 @@ void WebPRescalerImportRowExpand_C(WebPRescaler* const wrk,
     int x_out = channel;
     // simple bilinear interpolation
     int accum = wrk->x_add;
-    int left = src[x_in];
-    int right = (wrk->src_width > 1) ? src[x_in + x_stride] : left;
+    rescaler_t left = (rescaler_t)src[x_in];
+    rescaler_t right =
+        (wrk->src_width > 1) ? (rescaler_t)src[x_in + x_stride] : left;
     x_in += x_stride;
     while (1) {
       wrk->frow[x_out] = right * wrk->x_add + (left - right) * accum;
@@ -50,7 +51,7 @@ void WebPRescalerImportRowExpand_C(WebPRescaler* const wrk,
         left = right;
         x_in += x_stride;
         assert(x_in < wrk->src_width * x_stride);
-        right = src[x_in];
+        right = (rescaler_t)src[x_in];
         accum += wrk->x_add;
       }
     }
@@ -213,7 +214,7 @@ WEBP_DSP_INIT_FUNC(WebPRescalerDspInit) {
   WebPRescalerImportRowShrink = WebPRescalerImportRowShrink_C;
 
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       WebPRescalerDspInitSSE2();
     }
@@ -235,7 +236,7 @@ WEBP_DSP_INIT_FUNC(WebPRescalerDspInit) {
 #endif
   }
 
-#if defined(WEBP_USE_NEON)
+#if defined(WEBP_HAVE_NEON)
   if (WEBP_NEON_OMIT_C_CODE ||
       (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) {
     WebPRescalerDspInitNEON();
diff --git a/thirdparty/libwebp/src/dsp/ssim.c b/thirdparty/libwebp/src/dsp/ssim.c
index 989ce8254c..f85c2e6e5b 100644
--- a/thirdparty/libwebp/src/dsp/ssim.c
+++ b/thirdparty/libwebp/src/dsp/ssim.c
@@ -150,7 +150,7 @@ WEBP_DSP_INIT_FUNC(VP8SSIMDspInit) {
 #endif
 
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       VP8SSIMDspInitSSE2();
     }
diff --git a/thirdparty/libwebp/src/dsp/upsampling.c b/thirdparty/libwebp/src/dsp/upsampling.c
index 9b60da5bbb..87f771f3eb 100644
--- a/thirdparty/libwebp/src/dsp/upsampling.c
+++ b/thirdparty/libwebp/src/dsp/upsampling.c
@@ -233,12 +233,12 @@ WEBP_DSP_INIT_FUNC(WebPInitYUV444Converters) {
   WebPYUV444Converters[MODE_rgbA_4444] = WebPYuv444ToRgba4444_C;
 
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       WebPInitYUV444ConvertersSSE2();
     }
 #endif
-#if defined(WEBP_USE_SSE41)
+#if defined(WEBP_HAVE_SSE41)
     if (VP8GetCPUInfo(kSSE4_1)) {
       WebPInitYUV444ConvertersSSE41();
     }
@@ -278,12 +278,12 @@ WEBP_DSP_INIT_FUNC(WebPInitUpsamplers) {
 
   // If defined, use CPUInfo() to overwrite some pointers with faster versions.
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       WebPInitUpsamplersSSE2();
     }
 #endif
-#if defined(WEBP_USE_SSE41)
+#if defined(WEBP_HAVE_SSE41)
     if (VP8GetCPUInfo(kSSE4_1)) {
       WebPInitUpsamplersSSE41();
     }
@@ -300,7 +300,7 @@ WEBP_DSP_INIT_FUNC(WebPInitUpsamplers) {
 #endif
   }
 
-#if defined(WEBP_USE_NEON)
+#if defined(WEBP_HAVE_NEON)
   if (WEBP_NEON_OMIT_C_CODE ||
       (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) {
     WebPInitUpsamplersNEON();
diff --git a/thirdparty/libwebp/src/dsp/yuv.c b/thirdparty/libwebp/src/dsp/yuv.c
index 14e67fc28e..48466f8b11 100644
--- a/thirdparty/libwebp/src/dsp/yuv.c
+++ b/thirdparty/libwebp/src/dsp/yuv.c
@@ -90,16 +90,16 @@ WEBP_DSP_INIT_FUNC(WebPInitSamplers) {
 
   // If defined, use CPUInfo() to overwrite some pointers with faster versions.
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       WebPInitSamplersSSE2();
     }
-#endif  // WEBP_USE_SSE2
-#if defined(WEBP_USE_SSE41)
+#endif  // WEBP_HAVE_SSE2
+#if defined(WEBP_HAVE_SSE41)
     if (VP8GetCPUInfo(kSSE4_1)) {
       WebPInitSamplersSSE41();
     }
-#endif  // WEBP_USE_SSE41
+#endif  // WEBP_HAVE_SSE41
 #if defined(WEBP_USE_MIPS32)
     if (VP8GetCPUInfo(kMIPS32)) {
       WebPInitSamplersMIPS32();
@@ -276,26 +276,26 @@ WEBP_DSP_INIT_FUNC(WebPInitConvertARGBToYUV) {
 #endif
 
   if (VP8GetCPUInfo != NULL) {
-#if defined(WEBP_USE_SSE2)
+#if defined(WEBP_HAVE_SSE2)
     if (VP8GetCPUInfo(kSSE2)) {
       WebPInitConvertARGBToYUVSSE2();
       WebPInitSharpYUVSSE2();
     }
-#endif  // WEBP_USE_SSE2
-#if defined(WEBP_USE_SSE41)
+#endif  // WEBP_HAVE_SSE2
+#if defined(WEBP_HAVE_SSE41)
     if (VP8GetCPUInfo(kSSE4_1)) {
       WebPInitConvertARGBToYUVSSE41();
     }
-#endif  // WEBP_USE_SSE41
+#endif  // WEBP_HAVE_SSE41
   }
 
-#if defined(WEBP_USE_NEON)
+#if defined(WEBP_HAVE_NEON)
   if (WEBP_NEON_OMIT_C_CODE ||
       (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kNEON))) {
     WebPInitConvertARGBToYUVNEON();
     WebPInitSharpYUVNEON();
   }
-#endif  // WEBP_USE_NEON
+#endif  // WEBP_HAVE_NEON
 
   assert(WebPConvertARGBToY != NULL);
   assert(WebPConvertARGBToUV != NULL);
diff --git a/thirdparty/libwebp/src/enc/alpha_enc.c b/thirdparty/libwebp/src/enc/alpha_enc.c
index dce9ca957d..0b54f3e6ec 100644
--- a/thirdparty/libwebp/src/enc/alpha_enc.c
+++ b/thirdparty/libwebp/src/enc/alpha_enc.c
@@ -303,7 +303,7 @@ static int EncodeAlpha(VP8Encoder* const enc,
   int ok = 1;
   const int reduce_levels = (quality < 100);
 
-  // quick sanity checks
+  // quick correctness checks
   assert((uint64_t)data_size == (uint64_t)width * height);  // as per spec
   assert(enc != NULL && pic != NULL && pic->a != NULL);
   assert(output != NULL && output_size != NULL);
@@ -361,7 +361,7 @@ static int EncodeAlpha(VP8Encoder* const enc,
 //------------------------------------------------------------------------------
 // Main calls
 
-static int CompressAlphaJob(void* arg1, void* dummy) {
+static int CompressAlphaJob(void* arg1, void* unused) {
   VP8Encoder* const enc = (VP8Encoder*)arg1;
   const WebPConfig* config = enc->config_;
   uint8_t* alpha_data = NULL;
@@ -375,13 +375,13 @@ static int CompressAlphaJob(void* arg1, void* dummy) {
                    filter, effort_level, &alpha_data, &alpha_size)) {
     return 0;
   }
-  if (alpha_size != (uint32_t)alpha_size) {  // Sanity check.
+  if (alpha_size != (uint32_t)alpha_size) {  // Soundness check.
     WebPSafeFree(alpha_data);
     return 0;
   }
   enc->alpha_data_size_ = (uint32_t)alpha_size;
   enc->alpha_data_ = alpha_data;
-  (void)dummy;
+  (void)unused;
   return 1;
 }
 
diff --git a/thirdparty/libwebp/src/enc/analysis_enc.c b/thirdparty/libwebp/src/enc/analysis_enc.c
index 687757ae03..ebb784261c 100644
--- a/thirdparty/libwebp/src/enc/analysis_enc.c
+++ b/thirdparty/libwebp/src/enc/analysis_enc.c
@@ -126,16 +126,6 @@ static void InitHistogram(VP8Histogram* const histo) {
   histo->last_non_zero = 1;
 }
 
-static void MergeHistograms(const VP8Histogram* const in,
-                            VP8Histogram* const out) {
-  if (in->max_value > out->max_value) {
-    out->max_value = in->max_value;
-  }
-  if (in->last_non_zero > out->last_non_zero) {
-    out->last_non_zero = in->last_non_zero;
-  }
-}
-
 //------------------------------------------------------------------------------
 // Simplified k-Means, to assign Nb segments based on alpha-histogram
 
@@ -285,49 +275,6 @@ static int FastMBAnalyze(VP8EncIterator* const it) {
   return 0;
 }
 
-static int MBAnalyzeBestIntra4Mode(VP8EncIterator* const it,
-                                   int best_alpha) {
-  uint8_t modes[16];
-  const int max_mode = MAX_INTRA4_MODE;
-  int i4_alpha;
-  VP8Histogram total_histo;
-  int cur_histo = 0;
-  InitHistogram(&total_histo);
-
-  VP8IteratorStartI4(it);
-  do {
-    int mode;
-    int best_mode_alpha = DEFAULT_ALPHA;
-    VP8Histogram histos[2];
-    const uint8_t* const src = it->yuv_in_ + Y_OFF_ENC + VP8Scan[it->i4_];
-
-    VP8MakeIntra4Preds(it);
-    for (mode = 0; mode < max_mode; ++mode) {
-      int alpha;
-
-      InitHistogram(&histos[cur_histo]);
-      VP8CollectHistogram(src, it->yuv_p_ + VP8I4ModeOffsets[mode],
-                          0, 1, &histos[cur_histo]);
-      alpha = GetAlpha(&histos[cur_histo]);
-      if (IS_BETTER_ALPHA(alpha, best_mode_alpha)) {
-        best_mode_alpha = alpha;
-        modes[it->i4_] = mode;
-        cur_histo ^= 1;   // keep track of best histo so far.
-      }
-    }
-    // accumulate best histogram
-    MergeHistograms(&histos[cur_histo ^ 1], &total_histo);
-    // Note: we reuse the original samples for predictors
-  } while (VP8IteratorRotateI4(it, it->yuv_in_ + Y_OFF_ENC));
-
-  i4_alpha = GetAlpha(&total_histo);
-  if (IS_BETTER_ALPHA(i4_alpha, best_alpha)) {
-    VP8SetIntra4Mode(it, modes);
-    best_alpha = i4_alpha;
-  }
-  return best_alpha;
-}
-
 static int MBAnalyzeBestUVMode(VP8EncIterator* const it) {
   int best_alpha = DEFAULT_ALPHA;
   int smallest_alpha = 0;
@@ -371,13 +318,6 @@ static void MBAnalyze(VP8EncIterator* const it,
     best_alpha = FastMBAnalyze(it);
   } else {
     best_alpha = MBAnalyzeBestIntra16Mode(it);
-    if (enc->method_ >= 5) {
-      // We go and make a fast decision for intra4/intra16.
-      // It's usually not a good and definitive pick, but helps seeding the
-      // stats about level bit-cost.
-      // TODO(skal): improve criterion.
-      best_alpha = MBAnalyzeBestIntra4Mode(it, best_alpha);
-    }
   }
   best_uv_alpha = MBAnalyzeBestUVMode(it);
 
diff --git a/thirdparty/libwebp/src/enc/backward_references_enc.c b/thirdparty/libwebp/src/enc/backward_references_enc.c
index d445b40fc5..519b36a091 100644
--- a/thirdparty/libwebp/src/enc/backward_references_enc.c
+++ b/thirdparty/libwebp/src/enc/backward_references_enc.c
@@ -11,13 +11,14 @@
 //
 
 #include <assert.h>
+#include <float.h>
 #include <math.h>
 
-#include "src/enc/backward_references_enc.h"
-#include "src/enc/histogram_enc.h"
+#include "src/dsp/dsp.h"
 #include "src/dsp/lossless.h"
 #include "src/dsp/lossless_common.h"
-#include "src/dsp/dsp.h"
+#include "src/enc/backward_references_enc.h"
+#include "src/enc/histogram_enc.h"
 #include "src/utils/color_cache_utils.h"
 #include "src/utils/utils.h"
 
@@ -103,6 +104,20 @@ void VP8LBackwardRefsClear(VP8LBackwardRefs* const refs) {
   }
 }
 
+// Swaps the content of two VP8LBackwardRefs.
+static void BackwardRefsSwap(VP8LBackwardRefs* const refs1,
+                             VP8LBackwardRefs* const refs2) {
+  const int point_to_refs1 =
+      (refs1->tail_ != NULL && refs1->tail_ == &refs1->refs_);
+  const int point_to_refs2 =
+      (refs2->tail_ != NULL && refs2->tail_ == &refs2->refs_);
+  const VP8LBackwardRefs tmp = *refs1;
+  *refs1 = *refs2;
+  *refs2 = tmp;
+  if (point_to_refs2) refs1->tail_ = &refs1->refs_;
+  if (point_to_refs1) refs2->tail_ = &refs2->refs_;
+}
+
 void VP8LBackwardRefsInit(VP8LBackwardRefs* const refs, int block_size) {
   assert(refs != NULL);
   memset(refs, 0, sizeof(*refs));
@@ -154,6 +169,22 @@ static PixOrCopyBlock* BackwardRefsNewBlock(VP8LBackwardRefs* const refs) {
   return b;
 }
 
+// Return 1 on success, 0 on error.
+static int BackwardRefsClone(const VP8LBackwardRefs* const from,
+                             VP8LBackwardRefs* const to) {
+  const PixOrCopyBlock* block_from = from->refs_;
+  VP8LClearBackwardRefs(to);
+  while (block_from != NULL) {
+    PixOrCopyBlock* const block_to = BackwardRefsNewBlock(to);
+    if (block_to == NULL) return 0;
+    memcpy(block_to->start_, block_from->start_,
+           block_from->size_ * sizeof(PixOrCopy));
+    block_to->size_ = block_from->size_;
+    block_from = block_from->next_;
+  }
+  return 1;
+}
+
 extern void VP8LBackwardRefsCursorAdd(VP8LBackwardRefs* const refs,
                                       const PixOrCopy v);
 void VP8LBackwardRefsCursorAdd(VP8LBackwardRefs* const refs,
@@ -753,12 +784,18 @@ static int CalculateBestCacheSize(const uint32_t* argb, int quality,
         }
       }
     } else {
+      int code, extra_bits, extra_bits_value;
       // We should compute the contribution of the (distance,length)
       // histograms but those are the same independently from the cache size.
       // As those constant contributions are in the end added to the other
-      // histogram contributions, we can safely ignore them.
+      // histogram contributions, we can ignore them, except for the length
+      // prefix that is part of the literal_ histogram.
       int len = PixOrCopyLength(v);
       uint32_t argb_prev = *argb ^ 0xffffffffu;
+      VP8LPrefixEncode(len, &code, &extra_bits, &extra_bits_value);
+      for (i = 0; i <= cache_bits_max; ++i) {
+        ++histos[i]->literal_[NUM_LITERAL_CODES + code];
+      }
       // Update the color caches.
       do {
         if (*argb != argb_prev) {
@@ -842,16 +879,21 @@ extern int VP8LBackwardReferencesTraceBackwards(
     int xsize, int ysize, const uint32_t* const argb, int cache_bits,
     const VP8LHashChain* const hash_chain,
     const VP8LBackwardRefs* const refs_src, VP8LBackwardRefs* const refs_dst);
-static VP8LBackwardRefs* GetBackwardReferences(
-    int width, int height, const uint32_t* const argb, int quality,
-    int lz77_types_to_try, int* const cache_bits,
-    const VP8LHashChain* const hash_chain, VP8LBackwardRefs* best,
-    VP8LBackwardRefs* worst) {
-  const int cache_bits_initial = *cache_bits;
-  double bit_cost_best = -1;
+static int GetBackwardReferences(int width, int height,
+                                 const uint32_t* const argb, int quality,
+                                 int lz77_types_to_try, int cache_bits_max,
+                                 int do_no_cache,
+                                 const VP8LHashChain* const hash_chain,
+                                 VP8LBackwardRefs* const refs,
+                                 int* const cache_bits_best) {
   VP8LHistogram* histo = NULL;
-  int lz77_type, lz77_type_best = 0;
+  int i, lz77_type;
+  // Index 0 is for a color cache, index 1 for no cache (if needed).
+  int lz77_types_best[2] = {0, 0};
+  double bit_costs_best[2] = {DBL_MAX, DBL_MAX};
   VP8LHashChain hash_chain_box;
+  VP8LBackwardRefs* const refs_tmp = &refs[do_no_cache ? 2 : 1];
+  int status = 0;
   memset(&hash_chain_box, 0, sizeof(hash_chain_box));
 
   histo = VP8LAllocateHistogram(MAX_COLOR_CACHE_BITS);
@@ -860,86 +902,129 @@ static VP8LBackwardRefs* GetBackwardReferences(
   for (lz77_type = 1; lz77_types_to_try;
        lz77_types_to_try &= ~lz77_type, lz77_type <<= 1) {
     int res = 0;
-    double bit_cost;
-    int cache_bits_tmp = cache_bits_initial;
+    double bit_cost = 0.;
     if ((lz77_types_to_try & lz77_type) == 0) continue;
     switch (lz77_type) {
       case kLZ77RLE:
-        res = BackwardReferencesRle(width, height, argb, 0, worst);
+        res = BackwardReferencesRle(width, height, argb, 0, refs_tmp);
         break;
       case kLZ77Standard:
         // Compute LZ77 with no cache (0 bits), as the ideal LZ77 with a color
         // cache is not that different in practice.
-        res = BackwardReferencesLz77(width, height, argb, 0, hash_chain, worst);
+        res = BackwardReferencesLz77(width, height, argb, 0, hash_chain,
+                                     refs_tmp);
         break;
       case kLZ77Box:
         if (!VP8LHashChainInit(&hash_chain_box, width * height)) goto Error;
         res = BackwardReferencesLz77Box(width, height, argb, 0, hash_chain,
-                                        &hash_chain_box, worst);
+                                        &hash_chain_box, refs_tmp);
         break;
       default:
         assert(0);
     }
     if (!res) goto Error;
 
-    // Next, try with a color cache and update the references.
-    if (!CalculateBestCacheSize(argb, quality, worst, &cache_bits_tmp)) {
-      goto Error;
-    }
-    if (cache_bits_tmp > 0) {
-      if (!BackwardRefsWithLocalCache(argb, cache_bits_tmp, worst)) {
-        goto Error;
+    // Start with the no color cache case.
+    for (i = 1; i >= 0; --i) {
+      int cache_bits = (i == 1) ? 0 : cache_bits_max;
+
+      if (i == 1 && !do_no_cache) continue;
+
+      if (i == 0) {
+        // Try with a color cache.
+        if (!CalculateBestCacheSize(argb, quality, refs_tmp, &cache_bits)) {
+          goto Error;
+        }
+        if (cache_bits > 0) {
+          if (!BackwardRefsWithLocalCache(argb, cache_bits, refs_tmp)) {
+            goto Error;
+          }
+        }
       }
-    }
 
-    // Keep the best backward references.
-    VP8LHistogramCreate(histo, worst, cache_bits_tmp);
-    bit_cost = VP8LHistogramEstimateBits(histo);
-    if (lz77_type_best == 0 || bit_cost < bit_cost_best) {
-      VP8LBackwardRefs* const tmp = worst;
-      worst = best;
-      best = tmp;
-      bit_cost_best = bit_cost;
-      *cache_bits = cache_bits_tmp;
-      lz77_type_best = lz77_type;
+      if (i == 0 && do_no_cache && cache_bits == 0) {
+        // No need to re-compute bit_cost as it was computed at i == 1.
+      } else {
+        VP8LHistogramCreate(histo, refs_tmp, cache_bits);
+        bit_cost = VP8LHistogramEstimateBits(histo);
+      }
+
+      if (bit_cost < bit_costs_best[i]) {
+        if (i == 1) {
+          // Do not swap as the full cache analysis would have the wrong
+          // VP8LBackwardRefs to start with.
+          if (!BackwardRefsClone(refs_tmp, &refs[1])) goto Error;
+        } else {
+          BackwardRefsSwap(refs_tmp, &refs[0]);
+        }
+        bit_costs_best[i] = bit_cost;
+        lz77_types_best[i] = lz77_type;
+        if (i == 0) *cache_bits_best = cache_bits;
+      }
     }
   }
-  assert(lz77_type_best > 0);
+  assert(lz77_types_best[0] > 0);
+  assert(!do_no_cache || lz77_types_best[1] > 0);
 
   // Improve on simple LZ77 but only for high quality (TraceBackwards is
   // costly).
-  if ((lz77_type_best == kLZ77Standard || lz77_type_best == kLZ77Box) &&
-      quality >= 25) {
-    const VP8LHashChain* const hash_chain_tmp =
-        (lz77_type_best == kLZ77Standard) ? hash_chain : &hash_chain_box;
-    if (VP8LBackwardReferencesTraceBackwards(width, height, argb, *cache_bits,
-                                             hash_chain_tmp, best, worst)) {
-      double bit_cost_trace;
-      VP8LHistogramCreate(histo, worst, *cache_bits);
-      bit_cost_trace = VP8LHistogramEstimateBits(histo);
-      if (bit_cost_trace < bit_cost_best) best = worst;
+  for (i = 1; i >= 0; --i) {
+    if (i == 1 && !do_no_cache) continue;
+    if ((lz77_types_best[i] == kLZ77Standard ||
+         lz77_types_best[i] == kLZ77Box) &&
+        quality >= 25) {
+      const VP8LHashChain* const hash_chain_tmp =
+          (lz77_types_best[i] == kLZ77Standard) ? hash_chain : &hash_chain_box;
+      const int cache_bits = (i == 1) ? 0 : *cache_bits_best;
+      if (VP8LBackwardReferencesTraceBackwards(width, height, argb, cache_bits,
+                                               hash_chain_tmp, &refs[i],
+                                               refs_tmp)) {
+        double bit_cost_trace;
+        VP8LHistogramCreate(histo, refs_tmp, cache_bits);
+        bit_cost_trace = VP8LHistogramEstimateBits(histo);
+        if (bit_cost_trace < bit_costs_best[i]) {
+          BackwardRefsSwap(refs_tmp, &refs[i]);
+        }
+      }
     }
-  }
 
-  BackwardReferences2DLocality(width, best);
+    BackwardReferences2DLocality(width, &refs[i]);
+
+    if (i == 1 && lz77_types_best[0] == lz77_types_best[1] &&
+        *cache_bits_best == 0) {
+      // If the best cache size is 0 and we have the same best LZ77, just copy
+      // the data over and stop here.
+      if (!BackwardRefsClone(&refs[1], &refs[0])) goto Error;
+      break;
+    }
+  }
+  status = 1;
 
 Error:
   VP8LHashChainClear(&hash_chain_box);
   VP8LFreeHistogram(histo);
-  return best;
+  return status;
 }
 
-VP8LBackwardRefs* VP8LGetBackwardReferences(
+WebPEncodingError VP8LGetBackwardReferences(
     int width, int height, const uint32_t* const argb, int quality,
-    int low_effort, int lz77_types_to_try, int* const cache_bits,
-    const VP8LHashChain* const hash_chain, VP8LBackwardRefs* const refs_tmp1,
-    VP8LBackwardRefs* const refs_tmp2) {
+    int low_effort, int lz77_types_to_try, int cache_bits_max, int do_no_cache,
+    const VP8LHashChain* const hash_chain, VP8LBackwardRefs* const refs,
+    int* const cache_bits_best) {
   if (low_effort) {
-    return GetBackwardReferencesLowEffort(width, height, argb, cache_bits,
-                                          hash_chain, refs_tmp1);
+    VP8LBackwardRefs* refs_best;
+    *cache_bits_best = cache_bits_max;
+    refs_best = GetBackwardReferencesLowEffort(
+        width, height, argb, cache_bits_best, hash_chain, refs);
+    if (refs_best == NULL) return VP8_ENC_ERROR_OUT_OF_MEMORY;
+    // Set it in first position.
+    BackwardRefsSwap(refs_best, &refs[0]);
   } else {
-    return GetBackwardReferences(width, height, argb, quality,
-                                 lz77_types_to_try, cache_bits, hash_chain,
-                                 refs_tmp1, refs_tmp2);
+    if (!GetBackwardReferences(width, height, argb, quality, lz77_types_to_try,
+                               cache_bits_max, do_no_cache, hash_chain, refs,
+                               cache_bits_best)) {
+      return VP8_ENC_ERROR_OUT_OF_MEMORY;
+    }
   }
+  return VP8_ENC_OK;
 }
diff --git a/thirdparty/libwebp/src/enc/backward_references_enc.h b/thirdparty/libwebp/src/enc/backward_references_enc.h
index 103ddfdcb7..4c0267b41e 100644
--- a/thirdparty/libwebp/src/enc/backward_references_enc.h
+++ b/thirdparty/libwebp/src/enc/backward_references_enc.h
@@ -16,6 +16,7 @@
 #include <assert.h>
 #include <stdlib.h>
 #include "src/webp/types.h"
+#include "src/webp/encode.h"
 #include "src/webp/format_constants.h"
 
 #ifdef __cplusplus
@@ -218,14 +219,19 @@ enum VP8LLZ77Type {
 // Evaluates best possible backward references for specified quality.
 // The input cache_bits to 'VP8LGetBackwardReferences' sets the maximum cache
 // bits to use (passing 0 implies disabling the local color cache).
-// The optimal cache bits is evaluated and set for the *cache_bits parameter.
-// The return value is the pointer to the best of the two backward refs viz,
-// refs[0] or refs[1].
-VP8LBackwardRefs* VP8LGetBackwardReferences(
+// The optimal cache bits is evaluated and set for the *cache_bits_best
+// parameter with the matching refs_best.
+// If do_no_cache == 0, refs is an array of 2 values and the best
+// VP8LBackwardRefs is put in the first element.
+// If do_no_cache != 0, refs is an array of 3 values and the best
+// VP8LBackwardRefs is put in the first element, the best value with no-cache in
+// the second element.
+// In both cases, the last element is used as temporary internally.
+WebPEncodingError VP8LGetBackwardReferences(
     int width, int height, const uint32_t* const argb, int quality,
-    int low_effort, int lz77_types_to_try, int* const cache_bits,
-    const VP8LHashChain* const hash_chain, VP8LBackwardRefs* const refs_tmp1,
-    VP8LBackwardRefs* const refs_tmp2);
+    int low_effort, int lz77_types_to_try, int cache_bits_max, int do_no_cache,
+    const VP8LHashChain* const hash_chain, VP8LBackwardRefs* const refs,
+    int* const cache_bits_best);
 
 #ifdef __cplusplus
 }
diff --git a/thirdparty/libwebp/src/enc/config_enc.c b/thirdparty/libwebp/src/enc/config_enc.c
index 9d4828978e..3518b41403 100644
--- a/thirdparty/libwebp/src/enc/config_enc.c
+++ b/thirdparty/libwebp/src/enc/config_enc.c
@@ -39,6 +39,8 @@ int WebPConfigInitInternal(WebPConfig* config,
   config->partitions = 0;
   config->segments = 4;
   config->pass = 1;
+  config->qmin = 0;
+  config->qmax = 100;
   config->show_compressed = 0;
   config->preprocessing = 0;
   config->autofilter = 0;
@@ -106,6 +108,9 @@ int WebPValidateConfig(const WebPConfig* config) {
   if (config->filter_type < 0 || config->filter_type > 1) return 0;
   if (config->autofilter < 0 || config->autofilter > 1) return 0;
   if (config->pass < 1 || config->pass > 10) return 0;
+  if (config->qmin < 0 || config->qmax > 100 || config->qmin > config->qmax) {
+    return 0;
+  }
   if (config->show_compressed < 0 || config->show_compressed > 1) return 0;
   if (config->preprocessing < 0 || config->preprocessing > 7) return 0;
   if (config->partitions < 0 || config->partitions > 3) return 0;
diff --git a/thirdparty/libwebp/src/enc/frame_enc.c b/thirdparty/libwebp/src/enc/frame_enc.c
index 1aec376e44..af538d83ba 100644
--- a/thirdparty/libwebp/src/enc/frame_enc.c
+++ b/thirdparty/libwebp/src/enc/frame_enc.c
@@ -31,10 +31,15 @@
 // we allow 2k of extra head-room in PARTITION0 limit.
 #define PARTITION0_SIZE_LIMIT ((VP8_MAX_PARTITION0_SIZE - 2048ULL) << 11)
 
+static float Clamp(float v, float min, float max) {
+  return (v < min) ? min : (v > max) ? max : v;
+}
+
 typedef struct {  // struct for organizing convergence in either size or PSNR
   int is_first;
   float dq;
   float q, last_q;
+  float qmin, qmax;
   double value, last_value;   // PSNR or size
   double target;
   int do_size_search;
@@ -47,7 +52,9 @@ static int InitPassStats(const VP8Encoder* const enc, PassStats* const s) {
 
   s->is_first = 1;
   s->dq = 10.f;
-  s->q = s->last_q = enc->config_->quality;
+  s->qmin = 1.f * enc->config_->qmin;
+  s->qmax = 1.f * enc->config_->qmax;
+  s->q = s->last_q = Clamp(enc->config_->quality, s->qmin, s->qmax);
   s->target = do_size_search ? (double)target_size
             : (target_PSNR > 0.) ? target_PSNR
             : 40.;   // default, just in case
@@ -56,10 +63,6 @@ static int InitPassStats(const VP8Encoder* const enc, PassStats* const s) {
   return do_size_search;
 }
 
-static float Clamp(float v, float min, float max) {
-  return (v < min) ? min : (v > max) ? max : v;
-}
-
 static float ComputeNextQ(PassStats* const s) {
   float dq;
   if (s->is_first) {
@@ -75,7 +78,7 @@ static float ComputeNextQ(PassStats* const s) {
   s->dq = Clamp(dq, -30.f, 30.f);
   s->last_q = s->q;
   s->last_value = s->value;
-  s->q = Clamp(s->q + s->dq, 0.f, 100.f);
+  s->q = Clamp(s->q + s->dq, s->qmin, s->qmax);
   return s->q;
 }
 
@@ -848,9 +851,10 @@ int VP8EncTokenLoop(VP8Encoder* const enc) {
     }
 
 #if (DEBUG_SEARCH > 0)
-    printf("#%2d metric:%.1lf -> %.1lf   last_q=%.2lf q=%.2lf dq=%.2lf\n",
+    printf("#%2d metric:%.1lf -> %.1lf   last_q=%.2lf q=%.2lf dq=%.2lf "
+           " range:[%.1f, %.1f]\n",
            num_pass_left, stats.last_value, stats.value,
-           stats.last_q, stats.q, stats.dq);
+           stats.last_q, stats.q, stats.dq, stats.qmin, stats.qmax);
 #endif
     if (enc->max_i4_header_bits_ > 0 && size_p0 > PARTITION0_SIZE_LIMIT) {
       ++num_pass_left;
diff --git a/thirdparty/libwebp/src/enc/histogram_enc.c b/thirdparty/libwebp/src/enc/histogram_enc.c
index a4e6bf3a98..38a0cebcab 100644
--- a/thirdparty/libwebp/src/enc/histogram_enc.c
+++ b/thirdparty/libwebp/src/enc/histogram_enc.c
@@ -208,6 +208,7 @@ void VP8LHistogramAddSinglePixOrCopy(VP8LHistogram* const histo,
   } else if (PixOrCopyIsCacheIdx(v)) {
     const int literal_ix =
         NUM_LITERAL_CODES + NUM_LENGTH_CODES + PixOrCopyCacheIdx(v);
+    assert(histo->palette_code_bits_ != 0);
     ++histo->literal_[literal_ix];
   } else {
     int code, extra_bits;
@@ -1170,13 +1171,15 @@ static void RemoveEmptyHistograms(VP8LHistogramSet* const image_histo) {
 int VP8LGetHistoImageSymbols(int xsize, int ysize,
                              const VP8LBackwardRefs* const refs,
                              int quality, int low_effort,
-                             int histo_bits, int cache_bits,
+                             int histogram_bits, int cache_bits,
                              VP8LHistogramSet* const image_histo,
                              VP8LHistogram* const tmp_histo,
                              uint16_t* const histogram_symbols) {
   int ok = 0;
-  const int histo_xsize = histo_bits ? VP8LSubSampleSize(xsize, histo_bits) : 1;
-  const int histo_ysize = histo_bits ? VP8LSubSampleSize(ysize, histo_bits) : 1;
+  const int histo_xsize =
+      histogram_bits ? VP8LSubSampleSize(xsize, histogram_bits) : 1;
+  const int histo_ysize =
+      histogram_bits ? VP8LSubSampleSize(ysize, histogram_bits) : 1;
   const int image_histo_raw_size = histo_xsize * histo_ysize;
   VP8LHistogramSet* const orig_histo =
       VP8LAllocateHistogramSet(image_histo_raw_size, cache_bits);
@@ -1192,7 +1195,7 @@ int VP8LGetHistoImageSymbols(int xsize, int ysize,
   if (orig_histo == NULL || map_tmp == NULL) goto Error;
 
   // Construct the histograms from backward references.
-  HistogramBuild(xsize, histo_bits, refs, orig_histo);
+  HistogramBuild(xsize, histogram_bits, refs, orig_histo);
   // Copies the histograms and computes its bit_cost.
   // histogram_symbols is optimized
   HistogramCopyAndAnalyze(orig_histo, image_histo, &num_used,
diff --git a/thirdparty/libwebp/src/enc/histogram_enc.h b/thirdparty/libwebp/src/enc/histogram_enc.h
index 54c2d21783..c3428b5d55 100644
--- a/thirdparty/libwebp/src/enc/histogram_enc.h
+++ b/thirdparty/libwebp/src/enc/histogram_enc.h
@@ -64,8 +64,8 @@ void VP8LHistogramCreate(VP8LHistogram* const p,
                          const VP8LBackwardRefs* const refs,
                          int palette_code_bits);
 
-// Return the size of the histogram for a given palette_code_bits.
-int VP8LGetHistogramSize(int palette_code_bits);
+// Return the size of the histogram for a given cache_bits.
+int VP8LGetHistogramSize(int cache_bits);
 
 // Set the palette_code_bits and reset the stats.
 // If init_arrays is true, the arrays are also filled with 0's.
@@ -110,7 +110,7 @@ int VP8LGetHistoImageSymbols(int xsize, int ysize,
                              const VP8LBackwardRefs* const refs,
                              int quality, int low_effort,
                              int histogram_bits, int cache_bits,
-                             VP8LHistogramSet* const image_in,
+                             VP8LHistogramSet* const image_histo,
                              VP8LHistogram* const tmp_histo,
                              uint16_t* const histogram_symbols);
 
diff --git a/thirdparty/libwebp/src/enc/picture_csp_enc.c b/thirdparty/libwebp/src/enc/picture_csp_enc.c
index 718e014ed2..35eede9635 100644
--- a/thirdparty/libwebp/src/enc/picture_csp_enc.c
+++ b/thirdparty/libwebp/src/enc/picture_csp_enc.c
@@ -61,16 +61,14 @@ static int CheckNonOpaque(const uint8_t* alpha, int width, int height,
 // Checking for the presence of non-opaque alpha.
 int WebPPictureHasTransparency(const WebPPicture* picture) {
   if (picture == NULL) return 0;
-  if (!picture->use_argb) {
-    return CheckNonOpaque(picture->a, picture->width, picture->height,
-                          1, picture->a_stride);
-  } else {
+  if (picture->use_argb) {
     const int alpha_offset = ALPHA_OFFSET;
     return CheckNonOpaque((const uint8_t*)picture->argb + alpha_offset,
                           picture->width, picture->height,
                           4, picture->argb_stride * sizeof(*picture->argb));
   }
-  return 0;
+  return CheckNonOpaque(picture->a, picture->width, picture->height,
+                        1, picture->a_stride);
 }
 
 //------------------------------------------------------------------------------
@@ -90,8 +88,9 @@ int WebPPictureHasTransparency(const WebPPicture* picture) {
 static int kLinearToGammaTab[kGammaTabSize + 1];
 static uint16_t kGammaToLinearTab[256];
 static volatile int kGammaTablesOk = 0;
+static void InitGammaTables(void);
 
-static WEBP_TSAN_IGNORE_FUNCTION void InitGammaTables(void) {
+WEBP_DSP_INIT_FUNC(InitGammaTables) {
   if (!kGammaTablesOk) {
     int v;
     const double scale = (double)(1 << kGammaTabFix) / kGammaScale;
@@ -181,8 +180,9 @@ static uint32_t kLinearToGammaTabS[kGammaTabSize + 2];
 #define GAMMA_TO_LINEAR_BITS 14
 static uint32_t kGammaToLinearTabS[MAX_Y_T + 1];   // size scales with Y_FIX
 static volatile int kGammaTablesSOk = 0;
+static void InitGammaTablesS(void);
 
-static WEBP_TSAN_IGNORE_FUNCTION void InitGammaTablesS(void) {
+WEBP_DSP_INIT_FUNC(InitGammaTablesS) {
   assert(2 * GAMMA_TO_LINEAR_BITS < 32);  // we use uint32_t intermediate values
   if (!kGammaTablesSOk) {
     int v;
diff --git a/thirdparty/libwebp/src/enc/picture_rescale_enc.c b/thirdparty/libwebp/src/enc/picture_rescale_enc.c
index 58a6ae7b9d..a75f5d9c06 100644
--- a/thirdparty/libwebp/src/enc/picture_rescale_enc.c
+++ b/thirdparty/libwebp/src/enc/picture_rescale_enc.c
@@ -164,22 +164,25 @@ int WebPPictureCrop(WebPPicture* pic,
 //------------------------------------------------------------------------------
 // Simple picture rescaler
 
-static void RescalePlane(const uint8_t* src,
-                         int src_width, int src_height, int src_stride,
-                         uint8_t* dst,
-                         int dst_width, int dst_height, int dst_stride,
-                         rescaler_t* const work,
-                         int num_channels) {
+static int RescalePlane(const uint8_t* src,
+                        int src_width, int src_height, int src_stride,
+                        uint8_t* dst,
+                        int dst_width, int dst_height, int dst_stride,
+                        rescaler_t* const work,
+                        int num_channels) {
   WebPRescaler rescaler;
   int y = 0;
-  WebPRescalerInit(&rescaler, src_width, src_height,
-                   dst, dst_width, dst_height, dst_stride,
-                   num_channels, work);
+  if (!WebPRescalerInit(&rescaler, src_width, src_height,
+                        dst, dst_width, dst_height, dst_stride,
+                        num_channels, work)) {
+    return 0;
+  }
   while (y < src_height) {
     y += WebPRescalerImport(&rescaler, src_height - y,
                             src + y * src_stride, src_stride);
     WebPRescalerExport(&rescaler);
   }
+  return 1;
 }
 
 static void AlphaMultiplyARGB(WebPPicture* const pic, int inverse) {
@@ -222,25 +225,28 @@ int WebPPictureRescale(WebPPicture* pic, int width, int height) {
     // If present, we need to rescale alpha first (for AlphaMultiplyY).
     if (pic->a != NULL) {
       WebPInitAlphaProcessing();
-      RescalePlane(pic->a, prev_width, prev_height, pic->a_stride,
-                   tmp.a, width, height, tmp.a_stride, work, 1);
+      if (!RescalePlane(pic->a, prev_width, prev_height, pic->a_stride,
+                        tmp.a, width, height, tmp.a_stride, work, 1)) {
+        return 0;
+      }
     }
 
     // We take transparency into account on the luma plane only. That's not
     // totally exact blending, but still is a good approximation.
     AlphaMultiplyY(pic, 0);
-    RescalePlane(pic->y, prev_width, prev_height, pic->y_stride,
-                 tmp.y, width, height, tmp.y_stride, work, 1);
+    if (!RescalePlane(pic->y, prev_width, prev_height, pic->y_stride,
+                      tmp.y, width, height, tmp.y_stride, work, 1) ||
+        !RescalePlane(pic->u,
+                      HALVE(prev_width), HALVE(prev_height), pic->uv_stride,
+                      tmp.u,
+                      HALVE(width), HALVE(height), tmp.uv_stride, work, 1) ||
+        !RescalePlane(pic->v,
+                      HALVE(prev_width), HALVE(prev_height), pic->uv_stride,
+                      tmp.v,
+                      HALVE(width), HALVE(height), tmp.uv_stride, work, 1)) {
+      return 0;
+    }
     AlphaMultiplyY(&tmp, 1);
-
-    RescalePlane(pic->u,
-                 HALVE(prev_width), HALVE(prev_height), pic->uv_stride,
-                 tmp.u,
-                 HALVE(width), HALVE(height), tmp.uv_stride, work, 1);
-    RescalePlane(pic->v,
-                 HALVE(prev_width), HALVE(prev_height), pic->uv_stride,
-                 tmp.v,
-                 HALVE(width), HALVE(height), tmp.uv_stride, work, 1);
   } else {
     work = (rescaler_t*)WebPSafeMalloc(2ULL * width * 4, sizeof(*work));
     if (work == NULL) {
@@ -252,11 +258,12 @@ int WebPPictureRescale(WebPPicture* pic, int width, int height) {
     // the premultiplication afterward (while preserving the alpha channel).
     WebPInitAlphaProcessing();
     AlphaMultiplyARGB(pic, 0);
-    RescalePlane((const uint8_t*)pic->argb, prev_width, prev_height,
-                 pic->argb_stride * 4,
-                 (uint8_t*)tmp.argb, width, height,
-                 tmp.argb_stride * 4,
-                 work, 4);
+    if (!RescalePlane((const uint8_t*)pic->argb, prev_width, prev_height,
+                      pic->argb_stride * 4,
+                      (uint8_t*)tmp.argb, width, height,
+                      tmp.argb_stride * 4, work, 4)) {
+      return 0;
+    }
     AlphaMultiplyARGB(&tmp, 1);
   }
   WebPPictureFree(pic);
diff --git a/thirdparty/libwebp/src/enc/picture_tools_enc.c b/thirdparty/libwebp/src/enc/picture_tools_enc.c
index d0e8a495da..38cb01534a 100644
--- a/thirdparty/libwebp/src/enc/picture_tools_enc.c
+++ b/thirdparty/libwebp/src/enc/picture_tools_enc.c
@@ -83,6 +83,19 @@ static int SmoothenBlock(const uint8_t* a_ptr, int a_stride, uint8_t* y_ptr,
   return (count == 0);
 }
 
+void WebPReplaceTransparentPixels(WebPPicture* const pic, uint32_t color) {
+  if (pic != NULL && pic->use_argb) {
+    int y = pic->height;
+    uint32_t* argb = pic->argb;
+    color &= 0xffffffu;   // force alpha=0
+    WebPInitAlphaProcessing();
+    while (y-- > 0) {
+      WebPAlphaReplace(argb, pic->width, color);
+      argb += pic->argb_stride;
+    }
+  }
+}
+
 void WebPCleanupTransparentArea(WebPPicture* pic) {
   int x, y, w, h;
   if (pic == NULL) return;
@@ -165,24 +178,6 @@ void WebPCleanupTransparentArea(WebPPicture* pic) {
 #undef SIZE
 #undef SIZE2
 
-void WebPCleanupTransparentAreaLossless(WebPPicture* const pic) {
-  int x, y, w, h;
-  uint32_t* argb;
-  assert(pic != NULL && pic->use_argb);
-  w = pic->width;
-  h = pic->height;
-  argb = pic->argb;
-
-  for (y = 0; y < h; ++y) {
-    for (x = 0; x < w; ++x) {
-      if ((argb[x] & 0xff000000) == 0) {
-        argb[x] = 0x00000000;
-      }
-    }
-    argb += pic->argb_stride;
-  }
-}
-
 //------------------------------------------------------------------------------
 // Blend color and remove transparency info
 
diff --git a/thirdparty/libwebp/src/enc/syntax_enc.c b/thirdparty/libwebp/src/enc/syntax_enc.c
index a9e5a6cf0f..e18cf650ca 100644
--- a/thirdparty/libwebp/src/enc/syntax_enc.c
+++ b/thirdparty/libwebp/src/enc/syntax_enc.c
@@ -349,7 +349,7 @@ int VP8EncWrite(VP8Encoder* const enc) {
                                        (enc->alpha_data_size_ & 1);
     riff_size += CHUNK_HEADER_SIZE + padded_alpha_size;
   }
-  // Sanity check.
+  // RIFF size should fit in 32-bits.
   if (riff_size > 0xfffffffeU) {
     return WebPEncodingSetError(pic, VP8_ENC_ERROR_FILE_TOO_BIG);
   }
diff --git a/thirdparty/libwebp/src/enc/vp8i_enc.h b/thirdparty/libwebp/src/enc/vp8i_enc.h
index fedcaeea27..67e9509367 100644
--- a/thirdparty/libwebp/src/enc/vp8i_enc.h
+++ b/thirdparty/libwebp/src/enc/vp8i_enc.h
@@ -31,8 +31,8 @@ extern "C" {
 
 // version numbers
 #define ENC_MAJ_VERSION 1
-#define ENC_MIN_VERSION 1
-#define ENC_REV_VERSION 0
+#define ENC_MIN_VERSION 2
+#define ENC_REV_VERSION 1
 
 enum { MAX_LF_LEVELS = 64,       // Maximum loop filter level
        MAX_VARIABLE_LEVEL = 67,  // last (inclusive) level with variable cost
@@ -286,8 +286,7 @@ int VP8IteratorNext(VP8EncIterator* const it);
 // save the yuv_out_ boundary values to top_/left_ arrays for next iterations.
 void VP8IteratorSaveBoundary(VP8EncIterator* const it);
 // Report progression based on macroblock rows. Return 0 for user-abort request.
-int VP8IteratorProgress(const VP8EncIterator* const it,
-                        int final_delta_percent);
+int VP8IteratorProgress(const VP8EncIterator* const it, int delta);
 // Intra4x4 iterations
 void VP8IteratorStartI4(VP8EncIterator* const it);
 // returns true if not done.
@@ -505,9 +504,9 @@ int WebPPictureAllocARGB(WebPPicture* const picture, int width, int height);
 // Returns false in case of error (invalid param, out-of-memory).
 int WebPPictureAllocYUVA(WebPPicture* const picture, int width, int height);
 
-// Clean-up the RGB samples under fully transparent area, to help lossless
-// compressibility (no guarantee, though). Assumes that pic->use_argb is true.
-void WebPCleanupTransparentAreaLossless(WebPPicture* const pic);
+// Replace samples that are fully transparent by 'color' to help compressibility
+// (no guarantee, though). Assumes pic->use_argb is true.
+void WebPReplaceTransparentPixels(WebPPicture* const pic, uint32_t color);
 
 //------------------------------------------------------------------------------
 
diff --git a/thirdparty/libwebp/src/enc/vp8l_enc.c b/thirdparty/libwebp/src/enc/vp8l_enc.c
index 2efd403f77..e330e716f1 100644
--- a/thirdparty/libwebp/src/enc/vp8l_enc.c
+++ b/thirdparty/libwebp/src/enc/vp8l_enc.c
@@ -65,25 +65,22 @@ static WEBP_INLINE void SwapColor(uint32_t* const col1, uint32_t* const col2) {
   *col2 = tmp;
 }
 
-static void GreedyMinimizeDeltas(uint32_t palette[], int num_colors) {
-  // Find greedily always the closest color of the predicted color to minimize
-  // deltas in the palette. This reduces storage needs since the
-  // palette is stored with delta encoding.
-  uint32_t predict = 0x00000000;
-  int i, k;
-  for (i = 0; i < num_colors; ++i) {
-    int best_ix = i;
-    uint32_t best_score = ~0U;
-    for (k = i; k < num_colors; ++k) {
-      const uint32_t cur_score = PaletteColorDistance(palette[k], predict);
-      if (best_score > cur_score) {
-        best_score = cur_score;
-        best_ix = k;
-      }
+static WEBP_INLINE int SearchColorNoIdx(const uint32_t sorted[], uint32_t color,
+                                        int num_colors) {
+  int low = 0, hi = num_colors;
+  if (sorted[low] == color) return low;  // loop invariant: sorted[low] != color
+  while (1) {
+    const int mid = (low + hi) >> 1;
+    if (sorted[mid] == color) {
+      return mid;
+    } else if (sorted[mid] < color) {
+      low = mid;
+    } else {
+      hi = mid;
     }
-    SwapColor(&palette[best_ix], &palette[i]);
-    predict = palette[i];
   }
+  assert(0);
+  return 0;
 }
 
 // The palette has been sorted by alpha. This function checks if the other
@@ -92,7 +89,8 @@ static void GreedyMinimizeDeltas(uint32_t palette[], int num_colors) {
 // no benefit to re-organize them greedily. A monotonic development
 // would be spotted in green-only situations (like lossy alpha) or gray-scale
 // images.
-static int PaletteHasNonMonotonousDeltas(uint32_t palette[], int num_colors) {
+static int PaletteHasNonMonotonousDeltas(const uint32_t* const palette,
+                                         int num_colors) {
   uint32_t predict = 0x000000;
   int i;
   uint8_t sign_found = 0x00;
@@ -115,28 +113,215 @@ static int PaletteHasNonMonotonousDeltas(uint32_t palette[], int num_colors) {
   return (sign_found & (sign_found << 1)) != 0;  // two consequent signs.
 }
 
+static void PaletteSortMinimizeDeltas(const uint32_t* const palette_sorted,
+                                      int num_colors, uint32_t* const palette) {
+  uint32_t predict = 0x00000000;
+  int i, k;
+  memcpy(palette, palette_sorted, num_colors * sizeof(*palette));
+  if (!PaletteHasNonMonotonousDeltas(palette_sorted, num_colors)) return;
+  // Find greedily always the closest color of the predicted color to minimize
+  // deltas in the palette. This reduces storage needs since the
+  // palette is stored with delta encoding.
+  for (i = 0; i < num_colors; ++i) {
+    int best_ix = i;
+    uint32_t best_score = ~0U;
+    for (k = i; k < num_colors; ++k) {
+      const uint32_t cur_score = PaletteColorDistance(palette[k], predict);
+      if (best_score > cur_score) {
+        best_score = cur_score;
+        best_ix = k;
+      }
+    }
+    SwapColor(&palette[best_ix], &palette[i]);
+    predict = palette[i];
+  }
+}
+
+// Sort palette in increasing order and prepare an inverse mapping array.
+static void PrepareMapToPalette(const uint32_t palette[], uint32_t num_colors,
+                                uint32_t sorted[], uint32_t idx_map[]) {
+  uint32_t i;
+  memcpy(sorted, palette, num_colors * sizeof(*sorted));
+  qsort(sorted, num_colors, sizeof(*sorted), PaletteCompareColorsForQsort);
+  for (i = 0; i < num_colors; ++i) {
+    idx_map[SearchColorNoIdx(sorted, palette[i], num_colors)] = i;
+  }
+}
+
 // -----------------------------------------------------------------------------
-// Palette
+// Modified Zeng method from "A Survey on Palette Reordering
+// Methods for Improving the Compression of Color-Indexed Images" by Armando J.
+// Pinho and Antonio J. R. Neves.
+
+// Finds the biggest cooccurrence in the matrix.
+static void CoOccurrenceFindMax(const uint32_t* const cooccurrence,
+                                uint32_t num_colors, uint8_t* const c1,
+                                uint8_t* const c2) {
+  // Find the index that is most frequently located adjacent to other
+  // (different) indexes.
+  uint32_t best_sum = 0u;
+  uint32_t i, j, best_cooccurrence;
+  *c1 = 0u;
+  for (i = 0; i < num_colors; ++i) {
+    uint32_t sum = 0;
+    for (j = 0; j < num_colors; ++j) sum += cooccurrence[i * num_colors + j];
+    if (sum > best_sum) {
+      best_sum = sum;
+      *c1 = i;
+    }
+  }
+  // Find the index that is most frequently found adjacent to *c1.
+  *c2 = 0u;
+  best_cooccurrence = 0u;
+  for (i = 0; i < num_colors; ++i) {
+    if (cooccurrence[*c1 * num_colors + i] > best_cooccurrence) {
+      best_cooccurrence = cooccurrence[*c1 * num_colors + i];
+      *c2 = i;
+    }
+  }
+  assert(*c1 != *c2);
+}
 
-// If number of colors in the image is less than or equal to MAX_PALETTE_SIZE,
-// creates a palette and returns true, else returns false.
-static int AnalyzeAndCreatePalette(const WebPPicture* const pic,
-                                   int low_effort,
-                                   uint32_t palette[MAX_PALETTE_SIZE],
-                                   int* const palette_size) {
-  const int num_colors = WebPGetColorPalette(pic, palette);
-  if (num_colors > MAX_PALETTE_SIZE) {
-    *palette_size = 0;
-    return 0;
+// Builds the cooccurrence matrix
+static WebPEncodingError CoOccurrenceBuild(const WebPPicture* const pic,
+                                           const uint32_t* const palette,
+                                           uint32_t num_colors,
+                                           uint32_t* cooccurrence) {
+  uint32_t *lines, *line_top, *line_current, *line_tmp;
+  int x, y;
+  const uint32_t* src = pic->argb;
+  uint32_t prev_pix = ~src[0];
+  uint32_t prev_idx = 0u;
+  uint32_t idx_map[MAX_PALETTE_SIZE] = {0};
+  uint32_t palette_sorted[MAX_PALETTE_SIZE];
+  lines = (uint32_t*)WebPSafeMalloc(2 * pic->width, sizeof(*lines));
+  if (lines == NULL) return VP8_ENC_ERROR_OUT_OF_MEMORY;
+  line_top = &lines[0];
+  line_current = &lines[pic->width];
+  PrepareMapToPalette(palette, num_colors, palette_sorted, idx_map);
+  for (y = 0; y < pic->height; ++y) {
+    for (x = 0; x < pic->width; ++x) {
+      const uint32_t pix = src[x];
+      if (pix != prev_pix) {
+        prev_idx = idx_map[SearchColorNoIdx(palette_sorted, pix, num_colors)];
+        prev_pix = pix;
+      }
+      line_current[x] = prev_idx;
+      // 4-connectivity is what works best as mentioned in "On the relation
+      // between Memon's and the modified Zeng's palette reordering methods".
+      if (x > 0 && prev_idx != line_current[x - 1]) {
+        const uint32_t left_idx = line_current[x - 1];
+        ++cooccurrence[prev_idx * num_colors + left_idx];
+        ++cooccurrence[left_idx * num_colors + prev_idx];
+      }
+      if (y > 0 && prev_idx != line_top[x]) {
+        const uint32_t top_idx = line_top[x];
+        ++cooccurrence[prev_idx * num_colors + top_idx];
+        ++cooccurrence[top_idx * num_colors + prev_idx];
+      }
+    }
+    line_tmp = line_top;
+    line_top = line_current;
+    line_current = line_tmp;
+    src += pic->argb_stride;
+  }
+  WebPSafeFree(lines);
+  return VP8_ENC_OK;
+}
+
+struct Sum {
+  uint8_t index;
+  uint32_t sum;
+};
+
+// Implements the modified Zeng method from "A Survey on Palette Reordering
+// Methods for Improving the Compression of Color-Indexed Images" by Armando J.
+// Pinho and Antonio J. R. Neves.
+static WebPEncodingError PaletteSortModifiedZeng(
+    const WebPPicture* const pic, const uint32_t* const palette_sorted,
+    uint32_t num_colors, uint32_t* const palette) {
+  uint32_t i, j, ind;
+  uint8_t remapping[MAX_PALETTE_SIZE];
+  uint32_t* cooccurrence;
+  struct Sum sums[MAX_PALETTE_SIZE];
+  uint32_t first, last;
+  uint32_t num_sums;
+  // TODO(vrabaud) check whether one color images should use palette or not.
+  if (num_colors <= 1) return VP8_ENC_OK;
+  // Build the co-occurrence matrix.
+  cooccurrence =
+      (uint32_t*)WebPSafeCalloc(num_colors * num_colors, sizeof(*cooccurrence));
+  if (cooccurrence == NULL) return VP8_ENC_ERROR_OUT_OF_MEMORY;
+  if (CoOccurrenceBuild(pic, palette_sorted, num_colors, cooccurrence) !=
+      VP8_ENC_OK) {
+    WebPSafeFree(cooccurrence);
+    return VP8_ENC_ERROR_OUT_OF_MEMORY;
+  }
+
+  // Initialize the mapping list with the two best indices.
+  CoOccurrenceFindMax(cooccurrence, num_colors, &remapping[0], &remapping[1]);
+
+  // We need to append and prepend to the list of remapping. To this end, we
+  // actually define the next start/end of the list as indices in a vector (with
+  // a wrap around when the end is reached).
+  first = 0;
+  last = 1;
+  num_sums = num_colors - 2;  // -2 because we know the first two values
+  if (num_sums > 0) {
+    // Initialize the sums with the first two remappings and find the best one
+    struct Sum* best_sum = &sums[0];
+    best_sum->index = 0u;
+    best_sum->sum = 0u;
+    for (i = 0, j = 0; i < num_colors; ++i) {
+      if (i == remapping[0] || i == remapping[1]) continue;
+      sums[j].index = i;
+      sums[j].sum = cooccurrence[i * num_colors + remapping[0]] +
+                    cooccurrence[i * num_colors + remapping[1]];
+      if (sums[j].sum > best_sum->sum) best_sum = &sums[j];
+      ++j;
+    }
+
+    while (num_sums > 0) {
+      const uint8_t best_index = best_sum->index;
+      // Compute delta to know if we need to prepend or append the best index.
+      int32_t delta = 0;
+      const int32_t n = num_colors - num_sums;
+      for (ind = first, j = 0; (ind + j) % num_colors != last + 1; ++j) {
+        const uint16_t l_j = remapping[(ind + j) % num_colors];
+        delta += (n - 1 - 2 * (int32_t)j) *
+                 (int32_t)cooccurrence[best_index * num_colors + l_j];
+      }
+      if (delta > 0) {
+        first = (first == 0) ? num_colors - 1 : first - 1;
+        remapping[first] = best_index;
+      } else {
+        ++last;
+        remapping[last] = best_index;
+      }
+      // Remove best_sum from sums.
+      *best_sum = sums[num_sums - 1];
+      --num_sums;
+      // Update all the sums and find the best one.
+      best_sum = &sums[0];
+      for (i = 0; i < num_sums; ++i) {
+        sums[i].sum += cooccurrence[best_index * num_colors + sums[i].index];
+        if (sums[i].sum > best_sum->sum) best_sum = &sums[i];
+      }
+    }
   }
-  *palette_size = num_colors;
-  qsort(palette, num_colors, sizeof(*palette), PaletteCompareColorsForQsort);
-  if (!low_effort && PaletteHasNonMonotonousDeltas(palette, num_colors)) {
-    GreedyMinimizeDeltas(palette, num_colors);
+  assert((last + 1) % num_colors == first);
+  WebPSafeFree(cooccurrence);
+
+  // Re-map the palette.
+  for (i = 0; i < num_colors; ++i) {
+    palette[i] = palette_sorted[remapping[(first + i) % num_colors]];
   }
-  return 1;
+  return VP8_ENC_OK;
 }
 
+// -----------------------------------------------------------------------------
+// Palette
+
 // These five modes are evaluated and their respective entropy is computed.
 typedef enum {
   kDirect = 0,
@@ -144,10 +329,18 @@ typedef enum {
   kSubGreen = 2,
   kSpatialSubGreen = 3,
   kPalette = 4,
-  kNumEntropyIx = 5
+  kPaletteAndSpatial = 5,
+  kNumEntropyIx = 6
 } EntropyIx;
 
 typedef enum {
+  kSortedDefault = 0,
+  kMinimizeDelta = 1,
+  kModifiedZeng = 2,
+  kUnusedPalette = 3,
+} PaletteSorting;
+
+typedef enum {
   kHistoAlpha = 0,
   kHistoAlphaPred,
   kHistoGreen,
@@ -354,14 +547,21 @@ static int GetTransformBits(int method, int histo_bits) {
 }
 
 // Set of parameters to be used in each iteration of the cruncher.
-#define CRUNCH_CONFIGS_LZ77_MAX 2
+#define CRUNCH_SUBCONFIGS_MAX 2
+typedef struct {
+  int lz77_;
+  int do_no_cache_;
+} CrunchSubConfig;
 typedef struct {
   int entropy_idx_;
-  int lz77s_types_to_try_[CRUNCH_CONFIGS_LZ77_MAX];
-  int lz77s_types_to_try_size_;
+  PaletteSorting palette_sorting_type_;
+  CrunchSubConfig sub_configs_[CRUNCH_SUBCONFIGS_MAX];
+  int sub_configs_size_;
 } CrunchConfig;
 
-#define CRUNCH_CONFIGS_MAX kNumEntropyIx
+// +2 because we add a palette sorting configuration for kPalette and
+// kPaletteAndSpatial.
+#define CRUNCH_CONFIGS_MAX (kNumEntropyIx + 2)
 
 static int EncoderAnalyze(VP8LEncoder* const enc,
                           CrunchConfig crunch_configs[CRUNCH_CONFIGS_MAX],
@@ -376,11 +576,20 @@ static int EncoderAnalyze(VP8LEncoder* const enc,
   int i;
   int use_palette;
   int n_lz77s;
+  // If set to 0, analyze the cache with the computed cache value. If 1, also
+  // analyze with no-cache.
+  int do_no_cache = 0;
   assert(pic != NULL && pic->argb != NULL);
 
-  use_palette =
-      AnalyzeAndCreatePalette(pic, low_effort,
-                              enc->palette_, &enc->palette_size_);
+  // Check whether a palette is possible.
+  enc->palette_size_ = WebPGetColorPalette(pic, enc->palette_sorted_);
+  use_palette = (enc->palette_size_ <= MAX_PALETTE_SIZE);
+  if (!use_palette) {
+    enc->palette_size_ = 0;
+  } else {
+    qsort(enc->palette_sorted_, enc->palette_size_,
+          sizeof(*enc->palette_sorted_), PaletteCompareColorsForQsort);
+  }
 
   // Empirical bit sizes.
   enc->histo_bits_ = GetHistoBits(method, use_palette,
@@ -390,6 +599,8 @@ static int EncoderAnalyze(VP8LEncoder* const enc,
   if (low_effort) {
     // AnalyzeEntropy is somewhat slow.
     crunch_configs[0].entropy_idx_ = use_palette ? kPalette : kSpatialSubGreen;
+    crunch_configs[0].palette_sorting_type_ =
+        use_palette ? kSortedDefault : kUnusedPalette;
     n_lz77s = 1;
     *crunch_configs_size = 1;
   } else {
@@ -402,29 +613,59 @@ static int EncoderAnalyze(VP8LEncoder* const enc,
       return 0;
     }
     if (method == 6 && config->quality == 100) {
+      do_no_cache = 1;
       // Go brute force on all transforms.
       *crunch_configs_size = 0;
       for (i = 0; i < kNumEntropyIx; ++i) {
-        if (i != kPalette || use_palette) {
+        // We can only apply kPalette or kPaletteAndSpatial if we can indeed use
+        // a palette.
+        if ((i != kPalette && i != kPaletteAndSpatial) || use_palette) {
           assert(*crunch_configs_size < CRUNCH_CONFIGS_MAX);
-          crunch_configs[(*crunch_configs_size)++].entropy_idx_ = i;
+          crunch_configs[(*crunch_configs_size)].entropy_idx_ = i;
+          if (use_palette && (i == kPalette || i == kPaletteAndSpatial)) {
+            crunch_configs[(*crunch_configs_size)].palette_sorting_type_ =
+                kMinimizeDelta;
+            ++*crunch_configs_size;
+            // Also add modified Zeng's method.
+            crunch_configs[(*crunch_configs_size)].entropy_idx_ = i;
+            crunch_configs[(*crunch_configs_size)].palette_sorting_type_ =
+                kModifiedZeng;
+          } else {
+            crunch_configs[(*crunch_configs_size)].palette_sorting_type_ =
+                kUnusedPalette;
+          }
+          ++*crunch_configs_size;
         }
       }
     } else {
       // Only choose the guessed best transform.
       *crunch_configs_size = 1;
       crunch_configs[0].entropy_idx_ = min_entropy_ix;
+      crunch_configs[0].palette_sorting_type_ =
+          use_palette ? kMinimizeDelta : kUnusedPalette;
+      if (config->quality >= 75 && method == 5) {
+        // Test with and without color cache.
+        do_no_cache = 1;
+        // If we have a palette, also check in combination with spatial.
+        if (min_entropy_ix == kPalette) {
+          *crunch_configs_size = 2;
+          crunch_configs[1].entropy_idx_ = kPaletteAndSpatial;
+          crunch_configs[1].palette_sorting_type_ = kMinimizeDelta;
+        }
+      }
     }
   }
   // Fill in the different LZ77s.
-  assert(n_lz77s <= CRUNCH_CONFIGS_LZ77_MAX);
+  assert(n_lz77s <= CRUNCH_SUBCONFIGS_MAX);
   for (i = 0; i < *crunch_configs_size; ++i) {
     int j;
     for (j = 0; j < n_lz77s; ++j) {
-      crunch_configs[i].lz77s_types_to_try_[j] =
+      assert(j < CRUNCH_SUBCONFIGS_MAX);
+      crunch_configs[i].sub_configs_[j].lz77_ =
           (j == 0) ? kLZ77Standard | kLZ77RLE : kLZ77Box;
+      crunch_configs[i].sub_configs_[j].do_no_cache_ = do_no_cache;
     }
-    crunch_configs[i].lz77s_types_to_try_size_ = n_lz77s;
+    crunch_configs[i].sub_configs_size_ = n_lz77s;
   }
   return 1;
 }
@@ -440,7 +681,7 @@ static int EncoderInit(VP8LEncoder* const enc) {
   int i;
   if (!VP8LHashChainInit(&enc->hash_chain_, pix_cnt)) return 0;
 
-  for (i = 0; i < 3; ++i) VP8LBackwardRefsInit(&enc->refs_[i], refs_block_size);
+  for (i = 0; i < 4; ++i) VP8LBackwardRefsInit(&enc->refs_[i], refs_block_size);
 
   return 1;
 }
@@ -769,13 +1010,10 @@ static WebPEncodingError StoreImageToBitMask(
 }
 
 // Special case of EncodeImageInternal() for cache-bits=0, histo_bits=31
-static WebPEncodingError EncodeImageNoHuffman(VP8LBitWriter* const bw,
-                                              const uint32_t* const argb,
-                                              VP8LHashChain* const hash_chain,
-                                              VP8LBackwardRefs* const refs_tmp1,
-                                              VP8LBackwardRefs* const refs_tmp2,
-                                              int width, int height,
-                                              int quality, int low_effort) {
+static WebPEncodingError EncodeImageNoHuffman(
+    VP8LBitWriter* const bw, const uint32_t* const argb,
+    VP8LHashChain* const hash_chain, VP8LBackwardRefs* const refs_array,
+    int width, int height, int quality, int low_effort) {
   int i;
   int max_tokens = 0;
   WebPEncodingError err = VP8_ENC_OK;
@@ -798,13 +1036,11 @@ static WebPEncodingError EncodeImageNoHuffman(VP8LBitWriter* const bw,
     err = VP8_ENC_ERROR_OUT_OF_MEMORY;
     goto Error;
   }
-  refs = VP8LGetBackwardReferences(width, height, argb, quality, 0,
-                                   kLZ77Standard | kLZ77RLE, &cache_bits,
-                                   hash_chain, refs_tmp1, refs_tmp2);
-  if (refs == NULL) {
-    err = VP8_ENC_ERROR_OUT_OF_MEMORY;
-    goto Error;
-  }
+  err = VP8LGetBackwardReferences(
+      width, height, argb, quality, /*low_effort=*/0, kLZ77Standard | kLZ77RLE,
+      cache_bits, /*do_no_cache=*/0, hash_chain, refs_array, &cache_bits);
+  if (err != VP8_ENC_OK) goto Error;
+  refs = &refs_array[0];
   histogram_image = VP8LAllocateHistogramSet(1, cache_bits);
   if (histogram_image == NULL) {
     err = VP8_ENC_ERROR_OUT_OF_MEMORY;
@@ -860,11 +1096,11 @@ static WebPEncodingError EncodeImageNoHuffman(VP8LBitWriter* const bw,
 
 static WebPEncodingError EncodeImageInternal(
     VP8LBitWriter* const bw, const uint32_t* const argb,
-    VP8LHashChain* const hash_chain, VP8LBackwardRefs refs_array[3], int width,
+    VP8LHashChain* const hash_chain, VP8LBackwardRefs refs_array[4], int width,
     int height, int quality, int low_effort, int use_cache,
     const CrunchConfig* const config, int* cache_bits, int histogram_bits,
     size_t init_byte_position, int* const hdr_size, int* const data_size) {
-  WebPEncodingError err = VP8_ENC_OK;
+  WebPEncodingError err = VP8_ENC_ERROR_OUT_OF_MEMORY;
   const uint32_t histogram_image_xysize =
       VP8LSubSampleSize(width, histogram_bits) *
       VP8LSubSampleSize(height, histogram_bits);
@@ -876,103 +1112,103 @@ static WebPEncodingError EncodeImageInternal(
       3ULL * CODE_LENGTH_CODES, sizeof(*huff_tree));
   HuffmanTreeToken* tokens = NULL;
   HuffmanTreeCode* huffman_codes = NULL;
-  VP8LBackwardRefs* refs_best;
-  VP8LBackwardRefs* refs_tmp;
   uint16_t* const histogram_symbols =
       (uint16_t*)WebPSafeMalloc(histogram_image_xysize,
                                 sizeof(*histogram_symbols));
-  int lz77s_idx;
+  int sub_configs_idx;
+  int cache_bits_init, write_histogram_image;
   VP8LBitWriter bw_init = *bw, bw_best;
   int hdr_size_tmp;
+  VP8LHashChain hash_chain_histogram;  // histogram image hash chain
+  size_t bw_size_best = ~(size_t)0;
   assert(histogram_bits >= MIN_HUFFMAN_BITS);
   assert(histogram_bits <= MAX_HUFFMAN_BITS);
   assert(hdr_size != NULL);
   assert(data_size != NULL);
 
-  if (histogram_symbols == NULL) {
-    err = VP8_ENC_ERROR_OUT_OF_MEMORY;
+  // Make sure we can allocate the different objects.
+  memset(&hash_chain_histogram, 0, sizeof(hash_chain_histogram));
+  if (huff_tree == NULL || histogram_symbols == NULL ||
+      !VP8LHashChainInit(&hash_chain_histogram, histogram_image_xysize) ||
+      !VP8LHashChainFill(hash_chain, quality, argb, width, height,
+                         low_effort)) {
     goto Error;
   }
-
   if (use_cache) {
     // If the value is different from zero, it has been set during the
     // palette analysis.
-    if (*cache_bits == 0) *cache_bits = MAX_COLOR_CACHE_BITS;
+    cache_bits_init = (*cache_bits == 0) ? MAX_COLOR_CACHE_BITS : *cache_bits;
   } else {
-    *cache_bits = 0;
+    cache_bits_init = 0;
   }
-  // 'best_refs' is the reference to the best backward refs and points to one
-  // of refs_array[0] or refs_array[1].
-  // Calculate backward references from ARGB image.
-  if (huff_tree == NULL ||
-      !VP8LHashChainFill(hash_chain, quality, argb, width, height,
-                         low_effort) ||
-      !VP8LBitWriterInit(&bw_best, 0) ||
-      (config->lz77s_types_to_try_size_ > 1 &&
+  // If several iterations will happen, clone into bw_best.
+  if (!VP8LBitWriterInit(&bw_best, 0) ||
+      ((config->sub_configs_size_ > 1 ||
+        config->sub_configs_[0].do_no_cache_) &&
        !VP8LBitWriterClone(bw, &bw_best))) {
-    err = VP8_ENC_ERROR_OUT_OF_MEMORY;
     goto Error;
   }
-  for (lz77s_idx = 0; lz77s_idx < config->lz77s_types_to_try_size_;
-       ++lz77s_idx) {
-    refs_best = VP8LGetBackwardReferences(
-        width, height, argb, quality, low_effort,
-        config->lz77s_types_to_try_[lz77s_idx], cache_bits, hash_chain,
-        &refs_array[0], &refs_array[1]);
-    if (refs_best == NULL) {
-      err = VP8_ENC_ERROR_OUT_OF_MEMORY;
-      goto Error;
-    }
-    // Keep the best references aside and use the other element from the first
-    // two as a temporary for later usage.
-    refs_tmp = &refs_array[refs_best == &refs_array[0] ? 1 : 0];
-
-    histogram_image =
-        VP8LAllocateHistogramSet(histogram_image_xysize, *cache_bits);
-    tmp_histo = VP8LAllocateHistogram(*cache_bits);
-    if (histogram_image == NULL || tmp_histo == NULL) {
-      err = VP8_ENC_ERROR_OUT_OF_MEMORY;
-      goto Error;
-    }
-
-    // Build histogram image and symbols from backward references.
-    if (!VP8LGetHistoImageSymbols(width, height, refs_best, quality, low_effort,
-                                  histogram_bits, *cache_bits, histogram_image,
-                                  tmp_histo, histogram_symbols)) {
-      err = VP8_ENC_ERROR_OUT_OF_MEMORY;
-      goto Error;
-    }
-    // Create Huffman bit lengths and codes for each histogram image.
-    histogram_image_size = histogram_image->size;
-    bit_array_size = 5 * histogram_image_size;
-    huffman_codes = (HuffmanTreeCode*)WebPSafeCalloc(bit_array_size,
-                                                     sizeof(*huffman_codes));
-    // Note: some histogram_image entries may point to tmp_histos[], so the
-    // latter need to outlive the following call to GetHuffBitLengthsAndCodes().
-    if (huffman_codes == NULL ||
-        !GetHuffBitLengthsAndCodes(histogram_image, huffman_codes)) {
-      err = VP8_ENC_ERROR_OUT_OF_MEMORY;
-      goto Error;
-    }
-    // Free combined histograms.
-    VP8LFreeHistogramSet(histogram_image);
-    histogram_image = NULL;
-
-    // Free scratch histograms.
-    VP8LFreeHistogram(tmp_histo);
-    tmp_histo = NULL;
+  for (sub_configs_idx = 0; sub_configs_idx < config->sub_configs_size_;
+       ++sub_configs_idx) {
+    const CrunchSubConfig* const sub_config =
+        &config->sub_configs_[sub_configs_idx];
+    int cache_bits_best, i_cache;
+    err = VP8LGetBackwardReferences(width, height, argb, quality, low_effort,
+                                    sub_config->lz77_, cache_bits_init,
+                                    sub_config->do_no_cache_, hash_chain,
+                                    &refs_array[0], &cache_bits_best);
+    if (err != VP8_ENC_OK) goto Error;
 
-    // Color Cache parameters.
-    if (*cache_bits > 0) {
-      VP8LPutBits(bw, 1, 1);
-      VP8LPutBits(bw, *cache_bits, 4);
-    } else {
-      VP8LPutBits(bw, 0, 1);
-    }
+    for (i_cache = 0; i_cache < (sub_config->do_no_cache_ ? 2 : 1); ++i_cache) {
+      const int cache_bits_tmp = (i_cache == 0) ? cache_bits_best : 0;
+      // Speed-up: no need to study the no-cache case if it was already studied
+      // in i_cache == 0.
+      if (i_cache == 1 && cache_bits_best == 0) break;
+
+      // Reset the bit writer for this iteration.
+      VP8LBitWriterReset(&bw_init, bw);
+
+      // Build histogram image and symbols from backward references.
+      histogram_image =
+          VP8LAllocateHistogramSet(histogram_image_xysize, cache_bits_tmp);
+      tmp_histo = VP8LAllocateHistogram(cache_bits_tmp);
+      if (histogram_image == NULL || tmp_histo == NULL ||
+          !VP8LGetHistoImageSymbols(width, height, &refs_array[i_cache],
+                                    quality, low_effort, histogram_bits,
+                                    cache_bits_tmp, histogram_image, tmp_histo,
+                                    histogram_symbols)) {
+        goto Error;
+      }
+      // Create Huffman bit lengths and codes for each histogram image.
+      histogram_image_size = histogram_image->size;
+      bit_array_size = 5 * histogram_image_size;
+      huffman_codes = (HuffmanTreeCode*)WebPSafeCalloc(bit_array_size,
+                                                       sizeof(*huffman_codes));
+      // Note: some histogram_image entries may point to tmp_histos[], so the
+      // latter need to outlive the following call to
+      // GetHuffBitLengthsAndCodes().
+      if (huffman_codes == NULL ||
+          !GetHuffBitLengthsAndCodes(histogram_image, huffman_codes)) {
+        goto Error;
+      }
+      // Free combined histograms.
+      VP8LFreeHistogramSet(histogram_image);
+      histogram_image = NULL;
+
+      // Free scratch histograms.
+      VP8LFreeHistogram(tmp_histo);
+      tmp_histo = NULL;
+
+      // Color Cache parameters.
+      if (cache_bits_tmp > 0) {
+        VP8LPutBits(bw, 1, 1);
+        VP8LPutBits(bw, cache_bits_tmp, 4);
+      } else {
+        VP8LPutBits(bw, 0, 1);
+      }
 
-    // Huffman image + meta huffman.
-    {
-      const int write_histogram_image = (histogram_image_size > 1);
+      // Huffman image + meta huffman.
+      write_histogram_image = (histogram_image_size > 1);
       VP8LPutBits(bw, write_histogram_image, 1);
       if (write_histogram_image) {
         uint32_t* const histogram_argb =
@@ -980,10 +1216,7 @@ static WebPEncodingError EncodeImageInternal(
                                       sizeof(*histogram_argb));
         int max_index = 0;
         uint32_t i;
-        if (histogram_argb == NULL) {
-          err = VP8_ENC_ERROR_OUT_OF_MEMORY;
-          goto Error;
-        }
+        if (histogram_argb == NULL) goto Error;
         for (i = 0; i < histogram_image_xysize; ++i) {
           const int symbol_index = histogram_symbols[i] & 0xffff;
           histogram_argb[i] = (symbol_index << 8);
@@ -995,65 +1228,64 @@ static WebPEncodingError EncodeImageInternal(
 
         VP8LPutBits(bw, histogram_bits - 2, 3);
         err = EncodeImageNoHuffman(
-            bw, histogram_argb, hash_chain, refs_tmp, &refs_array[2],
+            bw, histogram_argb, &hash_chain_histogram, &refs_array[2],
             VP8LSubSampleSize(width, histogram_bits),
             VP8LSubSampleSize(height, histogram_bits), quality, low_effort);
         WebPSafeFree(histogram_argb);
         if (err != VP8_ENC_OK) goto Error;
       }
-    }
 
-    // Store Huffman codes.
-    {
-      int i;
-      int max_tokens = 0;
-      // Find maximum number of symbols for the huffman tree-set.
-      for (i = 0; i < 5 * histogram_image_size; ++i) {
-        HuffmanTreeCode* const codes = &huffman_codes[i];
-        if (max_tokens < codes->num_symbols) {
-          max_tokens = codes->num_symbols;
+      // Store Huffman codes.
+      {
+        int i;
+        int max_tokens = 0;
+        // Find maximum number of symbols for the huffman tree-set.
+        for (i = 0; i < 5 * histogram_image_size; ++i) {
+          HuffmanTreeCode* const codes = &huffman_codes[i];
+          if (max_tokens < codes->num_symbols) {
+            max_tokens = codes->num_symbols;
+          }
+        }
+        tokens = (HuffmanTreeToken*)WebPSafeMalloc(max_tokens, sizeof(*tokens));
+        if (tokens == NULL) goto Error;
+        for (i = 0; i < 5 * histogram_image_size; ++i) {
+          HuffmanTreeCode* const codes = &huffman_codes[i];
+          StoreHuffmanCode(bw, huff_tree, tokens, codes);
+          ClearHuffmanTreeIfOnlyOneSymbol(codes);
         }
       }
-      tokens = (HuffmanTreeToken*)WebPSafeMalloc(max_tokens, sizeof(*tokens));
-      if (tokens == NULL) {
-        err = VP8_ENC_ERROR_OUT_OF_MEMORY;
-        goto Error;
+      // Store actual literals.
+      hdr_size_tmp = (int)(VP8LBitWriterNumBytes(bw) - init_byte_position);
+      err = StoreImageToBitMask(bw, width, histogram_bits, &refs_array[i_cache],
+                                histogram_symbols, huffman_codes);
+      if (err != VP8_ENC_OK) goto Error;
+      // Keep track of the smallest image so far.
+      if (VP8LBitWriterNumBytes(bw) < bw_size_best) {
+        bw_size_best = VP8LBitWriterNumBytes(bw);
+        *cache_bits = cache_bits_tmp;
+        *hdr_size = hdr_size_tmp;
+        *data_size =
+            (int)(VP8LBitWriterNumBytes(bw) - init_byte_position - *hdr_size);
+        VP8LBitWriterSwap(bw, &bw_best);
       }
-      for (i = 0; i < 5 * histogram_image_size; ++i) {
-        HuffmanTreeCode* const codes = &huffman_codes[i];
-        StoreHuffmanCode(bw, huff_tree, tokens, codes);
-        ClearHuffmanTreeIfOnlyOneSymbol(codes);
+      WebPSafeFree(tokens);
+      tokens = NULL;
+      if (huffman_codes != NULL) {
+        WebPSafeFree(huffman_codes->codes);
+        WebPSafeFree(huffman_codes);
+        huffman_codes = NULL;
       }
     }
-    // Store actual literals.
-    hdr_size_tmp = (int)(VP8LBitWriterNumBytes(bw) - init_byte_position);
-    err = StoreImageToBitMask(bw, width, histogram_bits, refs_best,
-                              histogram_symbols, huffman_codes);
-    // Keep track of the smallest image so far.
-    if (lz77s_idx == 0 ||
-        VP8LBitWriterNumBytes(bw) < VP8LBitWriterNumBytes(&bw_best)) {
-      *hdr_size = hdr_size_tmp;
-      *data_size =
-          (int)(VP8LBitWriterNumBytes(bw) - init_byte_position - *hdr_size);
-      VP8LBitWriterSwap(bw, &bw_best);
-    }
-    // Reset the bit writer for the following iteration if any.
-    if (config->lz77s_types_to_try_size_ > 1) VP8LBitWriterReset(&bw_init, bw);
-    WebPSafeFree(tokens);
-    tokens = NULL;
-    if (huffman_codes != NULL) {
-      WebPSafeFree(huffman_codes->codes);
-      WebPSafeFree(huffman_codes);
-      huffman_codes = NULL;
-    }
   }
   VP8LBitWriterSwap(bw, &bw_best);
+  err = VP8_ENC_OK;
 
  Error:
   WebPSafeFree(tokens);
   WebPSafeFree(huff_tree);
   VP8LFreeHistogramSet(histogram_image);
   VP8LFreeHistogram(tmp_histo);
+  VP8LHashChainClear(&hash_chain_histogram);
   if (huffman_codes != NULL) {
     WebPSafeFree(huffman_codes->codes);
     WebPSafeFree(huffman_codes);
@@ -1095,8 +1327,7 @@ static WebPEncodingError ApplyPredictFilter(const VP8LEncoder* const enc,
   VP8LPutBits(bw, pred_bits - 2, 3);
   return EncodeImageNoHuffman(
       bw, enc->transform_data_, (VP8LHashChain*)&enc->hash_chain_,
-      (VP8LBackwardRefs*)&enc->refs_[0],  // cast const away
-      (VP8LBackwardRefs*)&enc->refs_[1], transform_width, transform_height,
+      (VP8LBackwardRefs*)&enc->refs_[0], transform_width, transform_height,
       quality, low_effort);
 }
 
@@ -1116,8 +1347,7 @@ static WebPEncodingError ApplyCrossColorFilter(const VP8LEncoder* const enc,
   VP8LPutBits(bw, ccolor_transform_bits - 2, 3);
   return EncodeImageNoHuffman(
       bw, enc->transform_data_, (VP8LHashChain*)&enc->hash_chain_,
-      (VP8LBackwardRefs*)&enc->refs_[0],  // cast const away
-      (VP8LBackwardRefs*)&enc->refs_[1], transform_width, transform_height,
+      (VP8LBackwardRefs*)&enc->refs_[0], transform_width, transform_height,
       quality, low_effort);
 }
 
@@ -1272,22 +1502,6 @@ static WebPEncodingError MakeInputImageCopy(VP8LEncoder* const enc) {
 
 // -----------------------------------------------------------------------------
 
-static WEBP_INLINE int SearchColorNoIdx(const uint32_t sorted[], uint32_t color,
-                                        int hi) {
-  int low = 0;
-  if (sorted[low] == color) return low;  // loop invariant: sorted[low] != color
-  while (1) {
-    const int mid = (low + hi) >> 1;
-    if (sorted[mid] == color) {
-      return mid;
-    } else if (sorted[mid] < color) {
-      low = mid;
-    } else {
-      hi = mid;
-    }
-  }
-}
-
 #define APPLY_PALETTE_GREEDY_MAX 4
 
 static WEBP_INLINE uint32_t SearchColorGreedy(const uint32_t palette[],
@@ -1322,17 +1536,6 @@ static WEBP_INLINE uint32_t ApplyPaletteHash2(uint32_t color) {
          (32 - PALETTE_INV_SIZE_BITS);
 }
 
-// Sort palette in increasing order and prepare an inverse mapping array.
-static void PrepareMapToPalette(const uint32_t palette[], int num_colors,
-                                uint32_t sorted[], uint32_t idx_map[]) {
-  int i;
-  memcpy(sorted, palette, num_colors * sizeof(*sorted));
-  qsort(sorted, num_colors, sizeof(*sorted), PaletteCompareColorsForQsort);
-  for (i = 0; i < num_colors; ++i) {
-    idx_map[SearchColorNoIdx(sorted, palette[i], num_colors)] = i;
-  }
-}
-
 // Use 1 pixel cache for ARGB pixels.
 #define APPLY_PALETTE_FOR(COLOR_INDEX) do {         \
   uint32_t prev_pix = palette[0];                   \
@@ -1464,8 +1667,8 @@ static WebPEncodingError EncodePalette(VP8LBitWriter* const bw, int low_effort,
   }
   tmp_palette[0] = palette[0];
   return EncodeImageNoHuffman(bw, tmp_palette, &enc->hash_chain_,
-                              &enc->refs_[0], &enc->refs_[1], palette_size, 1,
-                              20 /* quality */, low_effort);
+                              &enc->refs_[0], palette_size, 1, /*quality=*/20,
+                              low_effort);
 }
 
 // -----------------------------------------------------------------------------
@@ -1491,7 +1694,7 @@ static void VP8LEncoderDelete(VP8LEncoder* enc) {
   if (enc != NULL) {
     int i;
     VP8LHashChainClear(&enc->hash_chain_);
-    for (i = 0; i < 3; ++i) VP8LBackwardRefsClear(&enc->refs_[i]);
+    for (i = 0; i < 4; ++i) VP8LBackwardRefsClear(&enc->refs_[i]);
     ClearTransformBuffer(enc);
     WebPSafeFree(enc);
   }
@@ -1541,7 +1744,7 @@ static int EncodeStreamHook(void* input, void* data2) {
   int data_size = 0;
   int use_delta_palette = 0;
   int idx;
-  size_t best_size = 0;
+  size_t best_size = ~(size_t)0;
   VP8LBitWriter bw_init = *bw, bw_best;
   (void)data2;
 
@@ -1553,12 +1756,15 @@ static int EncodeStreamHook(void* input, void* data2) {
 
   for (idx = 0; idx < num_crunch_configs; ++idx) {
     const int entropy_idx = crunch_configs[idx].entropy_idx_;
-    enc->use_palette_ = (entropy_idx == kPalette);
+    enc->use_palette_ =
+        (entropy_idx == kPalette) || (entropy_idx == kPaletteAndSpatial);
     enc->use_subtract_green_ =
         (entropy_idx == kSubGreen) || (entropy_idx == kSpatialSubGreen);
-    enc->use_predict_ =
-        (entropy_idx == kSpatial) || (entropy_idx == kSpatialSubGreen);
-    if (low_effort) {
+    enc->use_predict_ = (entropy_idx == kSpatial) ||
+                        (entropy_idx == kSpatialSubGreen) ||
+                        (entropy_idx == kPaletteAndSpatial);
+    // When using a palette, R/B==0, hence no need to test for cross-color.
+    if (low_effort || enc->use_palette_) {
       enc->use_cross_color_ = 0;
     } else {
       enc->use_cross_color_ = red_and_blue_always_zero ? 0 : enc->use_predict_;
@@ -1590,6 +1796,19 @@ static int EncodeStreamHook(void* input, void* data2) {
 
     // Encode palette
     if (enc->use_palette_) {
+      if (crunch_configs[idx].palette_sorting_type_ == kSortedDefault) {
+        // Nothing to do, we have already sorted the palette.
+        memcpy(enc->palette_, enc->palette_sorted_,
+               enc->palette_size_ * sizeof(*enc->palette_));
+      } else if (crunch_configs[idx].palette_sorting_type_ == kMinimizeDelta) {
+        PaletteSortMinimizeDeltas(enc->palette_sorted_, enc->palette_size_,
+                                  enc->palette_);
+      } else {
+        assert(crunch_configs[idx].palette_sorting_type_ == kModifiedZeng);
+        err = PaletteSortModifiedZeng(enc->pic_, enc->palette_sorted_,
+                                      enc->palette_size_, enc->palette_);
+        if (err != VP8_ENC_OK) goto Error;
+      }
       err = EncodePalette(bw, low_effort, enc);
       if (err != VP8_ENC_OK) goto Error;
       err = MapImageFromPalette(enc, use_delta_palette);
@@ -1640,7 +1859,7 @@ static int EncodeStreamHook(void* input, void* data2) {
     if (err != VP8_ENC_OK) goto Error;
 
     // If we are better than what we already have.
-    if (idx == 0 || VP8LBitWriterNumBytes(bw) < best_size) {
+    if (VP8LBitWriterNumBytes(bw) < best_size) {
       best_size = VP8LBitWriterNumBytes(bw);
       // Store the BitWriter.
       VP8LBitWriterSwap(bw, &bw_best);
@@ -1754,6 +1973,8 @@ WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
         enc_side->palette_size_ = enc_main->palette_size_;
         memcpy(enc_side->palette_, enc_main->palette_,
                sizeof(enc_main->palette_));
+        memcpy(enc_side->palette_sorted_, enc_main->palette_sorted_,
+               sizeof(enc_main->palette_sorted_));
         param->enc_ = enc_side;
       }
       // Create the workers.
@@ -1816,7 +2037,7 @@ Error:
 }
 
 #undef CRUNCH_CONFIGS_MAX
-#undef CRUNCH_CONFIGS_LZ77_MAX
+#undef CRUNCH_SUBCONFIGS_MAX
 
 int VP8LEncodeImage(const WebPConfig* const config,
                     const WebPPicture* const picture) {
diff --git a/thirdparty/libwebp/src/enc/vp8li_enc.h b/thirdparty/libwebp/src/enc/vp8li_enc.h
index d2d0fc509c..00de48946c 100644
--- a/thirdparty/libwebp/src/enc/vp8li_enc.h
+++ b/thirdparty/libwebp/src/enc/vp8li_enc.h
@@ -69,9 +69,11 @@ typedef struct {
   int use_palette_;
   int palette_size_;
   uint32_t palette_[MAX_PALETTE_SIZE];
+  // Sorted version of palette_ for cache purposes.
+  uint32_t palette_sorted_[MAX_PALETTE_SIZE];
 
   // Some 'scratch' (potentially large) objects.
-  struct VP8LBackwardRefs refs_[3];  // Backward Refs array for temporaries.
+  struct VP8LBackwardRefs refs_[4];  // Backward Refs array for temporaries.
   VP8LHashChain hash_chain_;         // HashChain data for constructing
                                      // backward references.
 } VP8LEncoder;
diff --git a/thirdparty/libwebp/src/enc/webp_enc.c b/thirdparty/libwebp/src/enc/webp_enc.c
index 9f4b10c26c..ce2db2e94b 100644
--- a/thirdparty/libwebp/src/enc/webp_enc.c
+++ b/thirdparty/libwebp/src/enc/webp_enc.c
@@ -400,7 +400,7 @@ int WebPEncode(const WebPConfig* config, WebPPicture* pic) {
     }
 
     if (!config->exact) {
-      WebPCleanupTransparentAreaLossless(pic);
+      WebPReplaceTransparentPixels(pic, 0x000000);
     }
 
     ok = VP8LEncodeImage(config, pic);  // Sets pic->error in case of problem.
diff --git a/thirdparty/libwebp/src/mux/anim_encode.c b/thirdparty/libwebp/src/mux/anim_encode.c
index 7be99068f6..7078d9ae6b 100644
--- a/thirdparty/libwebp/src/mux/anim_encode.c
+++ b/thirdparty/libwebp/src/mux/anim_encode.c
@@ -248,9 +248,6 @@ WebPAnimEncoder* WebPAnimEncoderNewInternal(
 
   enc = (WebPAnimEncoder*)WebPSafeCalloc(1, sizeof(*enc));
   if (enc == NULL) return NULL;
-  // sanity inits, so we can call WebPAnimEncoderDelete():
-  enc->encoded_frames_ = NULL;
-  enc->mux_ = NULL;
   MarkNoError(enc);
 
   // Dimensions and options.
@@ -421,7 +418,7 @@ static void MinimizeChangeRectangle(const WebPPicture* const src,
   const int max_allowed_diff_lossy = QualityToMaxDiff(quality);
   const int max_allowed_diff = is_lossless ? 0 : max_allowed_diff_lossy;
 
-  // Sanity checks.
+  // Assumption/correctness checks.
   assert(src->width == dst->width && src->height == dst->height);
   assert(rect->x_offset_ + rect->width_ <= dst->width);
   assert(rect->y_offset_ + rect->height_ <= dst->height);
@@ -949,7 +946,8 @@ static int IncreasePreviousDuration(WebPAnimEncoder* const enc, int duration) {
   int new_duration;
 
   assert(enc->count_ >= 1);
-  assert(prev_enc_frame->sub_frame_.duration ==
+  assert(!prev_enc_frame->is_key_frame_ ||
+         prev_enc_frame->sub_frame_.duration ==
          prev_enc_frame->key_frame_.duration);
   assert(prev_enc_frame->sub_frame_.duration ==
          (prev_enc_frame->sub_frame_.duration & (MAX_DURATION - 1)));
@@ -966,7 +964,7 @@ static int IncreasePreviousDuration(WebPAnimEncoder* const enc, int duration) {
       0x10, 0x88, 0x88, 0x08
     };
     const WebPData lossless_1x1 = {
-        lossless_1x1_bytes, sizeof(lossless_1x1_bytes)
+      lossless_1x1_bytes, sizeof(lossless_1x1_bytes)
     };
     const uint8_t lossy_1x1_bytes[] = {
       0x52, 0x49, 0x46, 0x46, 0x40, 0x00, 0x00, 0x00, 0x57, 0x45, 0x42, 0x50,
@@ -1358,6 +1356,12 @@ int WebPAnimEncoderAdd(WebPAnimEncoder* enc, WebPPicture* frame, int timestamp,
     if (!IncreasePreviousDuration(enc, (int)prev_frame_duration)) {
       return 0;
     }
+    // IncreasePreviousDuration() may add a frame to avoid exceeding
+    // MAX_DURATION which could cause CacheFrame() to over read encoded_frames_
+    // before the next flush.
+    if (enc->count_ == enc->size_ && !FlushFrames(enc)) {
+      return 0;
+    }
   } else {
     enc->first_timestamp_ = timestamp;
   }
diff --git a/thirdparty/libwebp/src/mux/muxedit.c b/thirdparty/libwebp/src/mux/muxedit.c
index ccf14b2a0c..02c3edecd7 100644
--- a/thirdparty/libwebp/src/mux/muxedit.c
+++ b/thirdparty/libwebp/src/mux/muxedit.c
@@ -235,7 +235,6 @@ WebPMuxError WebPMuxSetImage(WebPMux* mux, const WebPData* bitstream,
   WebPMuxImage wpi;
   WebPMuxError err;
 
-  // Sanity checks.
   if (mux == NULL || bitstream == NULL || bitstream->bytes == NULL ||
       bitstream->size > MAX_CHUNK_PAYLOAD) {
     return WEBP_MUX_INVALID_ARGUMENT;
@@ -267,7 +266,6 @@ WebPMuxError WebPMuxPushFrame(WebPMux* mux, const WebPMuxFrameInfo* info,
   WebPMuxImage wpi;
   WebPMuxError err;
 
-  // Sanity checks.
   if (mux == NULL || info == NULL) return WEBP_MUX_INVALID_ARGUMENT;
 
   if (info->id != WEBP_CHUNK_ANMF) return WEBP_MUX_INVALID_ARGUMENT;
diff --git a/thirdparty/libwebp/src/mux/muxi.h b/thirdparty/libwebp/src/mux/muxi.h
index ad3e1bdb97..330da66754 100644
--- a/thirdparty/libwebp/src/mux/muxi.h
+++ b/thirdparty/libwebp/src/mux/muxi.h
@@ -28,8 +28,8 @@ extern "C" {
 // Defines and constants.
 
 #define MUX_MAJ_VERSION 1
-#define MUX_MIN_VERSION 1
-#define MUX_REV_VERSION 0
+#define MUX_MIN_VERSION 2
+#define MUX_REV_VERSION 1
 
 // Chunk object.
 typedef struct WebPChunk WebPChunk;
diff --git a/thirdparty/libwebp/src/mux/muxread.c b/thirdparty/libwebp/src/mux/muxread.c
index ae3b876bc5..80050396e1 100644
--- a/thirdparty/libwebp/src/mux/muxread.c
+++ b/thirdparty/libwebp/src/mux/muxread.c
@@ -56,7 +56,7 @@ static WebPMuxError ChunkVerifyAndAssign(WebPChunk* chunk,
   uint32_t chunk_size;
   WebPData chunk_data;
 
-  // Sanity checks.
+  // Correctness checks.
   if (data_size < CHUNK_HEADER_SIZE) return WEBP_MUX_NOT_ENOUGH_DATA;
   chunk_size = GetLE32(data + TAG_SIZE);
   if (chunk_size > MAX_CHUNK_PAYLOAD) return WEBP_MUX_BAD_DATA;
@@ -155,7 +155,6 @@ static int MuxImageParse(const WebPChunk* const chunk, int copy_data,
         break;
       default:
         goto Fail;
-        break;
     }
     subchunk_size = ChunkDiskSize(&subchunk);
     bytes += subchunk_size;
@@ -187,7 +186,6 @@ WebPMux* WebPMuxCreateInternal(const WebPData* bitstream, int copy_data,
   WebPChunk** chunk_list_ends[WEBP_CHUNK_NIL + 1] = { NULL };
   ChunkInit(&chunk);
 
-  // Sanity checks.
   if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_MUX_ABI_VERSION)) {
     return NULL;  // version mismatch
   }
@@ -264,7 +262,6 @@ WebPMux* WebPMuxCreateInternal(const WebPData* bitstream, int copy_data,
         if (!MuxImageParse(&chunk, copy_data, wpi)) goto Err;
         ChunkRelease(&chunk);
         goto PushImage;
-        break;
       default:  // A non-image chunk.
         if (wpi->is_partial_) goto Err;  // Encountered a non-image chunk before
                                          // getting all chunks of an image.
@@ -483,7 +480,6 @@ WebPMuxError WebPMuxGetFrame(
   WebPMuxError err;
   WebPMuxImage* wpi;
 
-  // Sanity checks.
   if (mux == NULL || frame == NULL) {
     return WEBP_MUX_INVALID_ARGUMENT;
   }
diff --git a/thirdparty/libwebp/src/utils/bit_reader_inl_utils.h b/thirdparty/libwebp/src/utils/bit_reader_inl_utils.h
index 46b3880706..404b9a6d8c 100644
--- a/thirdparty/libwebp/src/utils/bit_reader_inl_utils.h
+++ b/thirdparty/libwebp/src/utils/bit_reader_inl_utils.h
@@ -55,7 +55,7 @@ void VP8LoadFinalBytes(VP8BitReader* const br);
 
 // makes sure br->value_ has at least BITS bits worth of data
 static WEBP_UBSAN_IGNORE_UNDEF WEBP_INLINE
-void VP8LoadNewBytes(VP8BitReader* const br) {
+void VP8LoadNewBytes(VP8BitReader* WEBP_RESTRICT const br) {
   assert(br != NULL && br->buf_ != NULL);
   // Read 'BITS' bits at a time if possible.
   if (br->buf_ < br->buf_max_) {
@@ -104,7 +104,7 @@ void VP8LoadNewBytes(VP8BitReader* const br) {
 }
 
 // Read a bit with proba 'prob'. Speed-critical function!
-static WEBP_INLINE int VP8GetBit(VP8BitReader* const br,
+static WEBP_INLINE int VP8GetBit(VP8BitReader* WEBP_RESTRICT const br,
                                  int prob, const char label[]) {
   // Don't move this declaration! It makes a big speed difference to store
   // 'range' *before* calling VP8LoadNewBytes(), even if this function doesn't
@@ -137,7 +137,8 @@ static WEBP_INLINE int VP8GetBit(VP8BitReader* const br,
 
 // simplified version of VP8GetBit() for prob=0x80 (note shift is always 1 here)
 static WEBP_UBSAN_IGNORE_UNSIGNED_OVERFLOW WEBP_INLINE
-int VP8GetSigned(VP8BitReader* const br, int v, const char label[]) {
+int VP8GetSigned(VP8BitReader* WEBP_RESTRICT const br, int v,
+                 const char label[]) {
   if (br->bits_ < 0) {
     VP8LoadNewBytes(br);
   }
@@ -155,7 +156,7 @@ int VP8GetSigned(VP8BitReader* const br, int v, const char label[]) {
   }
 }
 
-static WEBP_INLINE int VP8GetBitAlt(VP8BitReader* const br,
+static WEBP_INLINE int VP8GetBitAlt(VP8BitReader* WEBP_RESTRICT const br,
                                     int prob, const char label[]) {
   // Don't move this declaration! It makes a big speed difference to store
   // 'range' *before* calling VP8LoadNewBytes(), even if this function doesn't
diff --git a/thirdparty/libwebp/src/utils/bit_reader_utils.c b/thirdparty/libwebp/src/utils/bit_reader_utils.c
index 60271c0ae0..857cd60988 100644
--- a/thirdparty/libwebp/src/utils/bit_reader_utils.c
+++ b/thirdparty/libwebp/src/utils/bit_reader_utils.c
@@ -41,14 +41,7 @@ void VP8InitBitReader(VP8BitReader* const br,
   br->bits_    = -8;   // to load the very first 8bits
   br->eof_     = 0;
   VP8BitReaderSetBuffer(br, start, size);
-// -- GODOT -- begin
-#ifdef JAVASCRIPT_ENABLED // html5 required aligned reads
-  while(((uintptr_t)br->buf_ & 1) != 0 && !br->eof_)
-    VP8LoadFinalBytes(br);
-#else
   VP8LoadNewBytes(br);
-#endif
-// -- GODOT -- end
 }
 
 void VP8RemapBitReader(VP8BitReader* const br, ptrdiff_t offset) {
diff --git a/thirdparty/libwebp/src/utils/bit_reader_utils.h b/thirdparty/libwebp/src/utils/bit_reader_utils.h
index 199dacf224..e64156e318 100644
--- a/thirdparty/libwebp/src/utils/bit_reader_utils.h
+++ b/thirdparty/libwebp/src/utils/bit_reader_utils.h
@@ -58,12 +58,6 @@ extern "C" {
 // BITS can be any multiple of 8 from 8 to 56 (inclusive).
 // Pick values that fit natural register size.
 
-// -- GODOT -- start
-#ifdef JAVASCRIPT_ENABLED
-#define BITS 16
-#else
-// -- GODOT -- end
-
 #if defined(__i386__) || defined(_M_IX86)      // x86 32bit
 #define BITS 24
 #elif defined(__x86_64__) || defined(_M_X64)   // x86 64bit
@@ -78,10 +72,6 @@ extern "C" {
 #define BITS 24
 #endif
 
-// -- GODOT -- start
-#endif
-// -- GODOT -- end
-
 //------------------------------------------------------------------------------
 // Derived types and constants:
 //   bit_t = natural register type for storing 'value_' (which is BITS+8 bits)
diff --git a/thirdparty/libwebp/src/utils/bit_writer_utils.c b/thirdparty/libwebp/src/utils/bit_writer_utils.c
index bef0e31ca5..2f408508f1 100644
--- a/thirdparty/libwebp/src/utils/bit_writer_utils.c
+++ b/thirdparty/libwebp/src/utils/bit_writer_utils.c
@@ -278,7 +278,7 @@ void VP8LPutBitsFlushBits(VP8LBitWriter* const bw) {
   // If needed, make some room by flushing some bits out.
   if (bw->cur_ + VP8L_WRITER_BYTES > bw->end_) {
     const uint64_t extra_size = (bw->end_ - bw->buf_) + MIN_EXTRA_SIZE;
-    if (extra_size != (size_t)extra_size ||
+    if (!CheckSizeOverflow(extra_size) ||
         !VP8LBitWriterResize(bw, (size_t)extra_size)) {
       bw->cur_ = bw->buf_;
       bw->error_ = 1;
@@ -314,7 +314,7 @@ void VP8LPutBitsInternal(VP8LBitWriter* const bw, uint32_t bits, int n_bits) {
     while (used >= VP8L_WRITER_BITS) {
       if (bw->cur_ + VP8L_WRITER_BYTES > bw->end_) {
         const uint64_t extra_size = (bw->end_ - bw->buf_) + MIN_EXTRA_SIZE;
-        if (extra_size != (size_t)extra_size ||
+        if (!CheckSizeOverflow(extra_size) ||
             !VP8LBitWriterResize(bw, (size_t)extra_size)) {
           bw->cur_ = bw->buf_;
           bw->error_ = 1;
diff --git a/thirdparty/libwebp/src/utils/color_cache_utils.c b/thirdparty/libwebp/src/utils/color_cache_utils.c
index b09f538e8b..7b5222b6e5 100644
--- a/thirdparty/libwebp/src/utils/color_cache_utils.c
+++ b/thirdparty/libwebp/src/utils/color_cache_utils.c
@@ -20,22 +20,22 @@
 //------------------------------------------------------------------------------
 // VP8LColorCache.
 
-int VP8LColorCacheInit(VP8LColorCache* const cc, int hash_bits) {
+int VP8LColorCacheInit(VP8LColorCache* const color_cache, int hash_bits) {
   const int hash_size = 1 << hash_bits;
-  assert(cc != NULL);
+  assert(color_cache != NULL);
   assert(hash_bits > 0);
-  cc->colors_ = (uint32_t*)WebPSafeCalloc((uint64_t)hash_size,
-                                          sizeof(*cc->colors_));
-  if (cc->colors_ == NULL) return 0;
-  cc->hash_shift_ = 32 - hash_bits;
-  cc->hash_bits_ = hash_bits;
+  color_cache->colors_ = (uint32_t*)WebPSafeCalloc(
+      (uint64_t)hash_size, sizeof(*color_cache->colors_));
+  if (color_cache->colors_ == NULL) return 0;
+  color_cache->hash_shift_ = 32 - hash_bits;
+  color_cache->hash_bits_ = hash_bits;
   return 1;
 }
 
-void VP8LColorCacheClear(VP8LColorCache* const cc) {
-  if (cc != NULL) {
-    WebPSafeFree(cc->colors_);
-    cc->colors_ = NULL;
+void VP8LColorCacheClear(VP8LColorCache* const color_cache) {
+  if (color_cache != NULL) {
+    WebPSafeFree(color_cache->colors_);
+    color_cache->colors_ = NULL;
   }
 }
 
diff --git a/thirdparty/libwebp/src/utils/huffman_encode_utils.c b/thirdparty/libwebp/src/utils/huffman_encode_utils.c
index 6f3b1bbe02..fd7a47d8f7 100644
--- a/thirdparty/libwebp/src/utils/huffman_encode_utils.c
+++ b/thirdparty/libwebp/src/utils/huffman_encode_utils.c
@@ -404,8 +404,7 @@ static void ConvertBitDepthsToSymbols(HuffmanTreeCode* const tree) {
 // Main entry point
 
 void VP8LCreateHuffmanTree(uint32_t* const histogram, int tree_depth_limit,
-                           uint8_t* const buf_rle,
-                           HuffmanTree* const huff_tree,
+                           uint8_t* const buf_rle, HuffmanTree* const huff_tree,
                            HuffmanTreeCode* const huff_code) {
   const int num_symbols = huff_code->num_symbols;
   memset(buf_rle, 0, num_symbols * sizeof(*buf_rle));
diff --git a/thirdparty/libwebp/src/utils/huffman_encode_utils.h b/thirdparty/libwebp/src/utils/huffman_encode_utils.h
index 3e6763ce49..3f7f1d8074 100644
--- a/thirdparty/libwebp/src/utils/huffman_encode_utils.h
+++ b/thirdparty/libwebp/src/utils/huffman_encode_utils.h
@@ -51,7 +51,7 @@ int VP8LCreateCompressedHuffmanTree(const HuffmanTreeCode* const tree,
 // huffman code tree.
 void VP8LCreateHuffmanTree(uint32_t* const histogram, int tree_depth_limit,
                            uint8_t* const buf_rle, HuffmanTree* const huff_tree,
-                           HuffmanTreeCode* const tree);
+                           HuffmanTreeCode* const huff_code);
 
 #ifdef __cplusplus
 }
diff --git a/thirdparty/libwebp/src/utils/rescaler_utils.c b/thirdparty/libwebp/src/utils/rescaler_utils.c
index 4bcae24af5..a0581a14b1 100644
--- a/thirdparty/libwebp/src/utils/rescaler_utils.c
+++ b/thirdparty/libwebp/src/utils/rescaler_utils.c
@@ -12,66 +12,74 @@
 // Author: Skal (pascal.massimino@gmail.com)
 
 #include <assert.h>
+#include <limits.h>
 #include <stdlib.h>
 #include <string.h>
 #include "src/dsp/dsp.h"
 #include "src/utils/rescaler_utils.h"
+#include "src/utils/utils.h"
 
 //------------------------------------------------------------------------------
 
-void WebPRescalerInit(WebPRescaler* const wrk, int src_width, int src_height,
-                      uint8_t* const dst,
-                      int dst_width, int dst_height, int dst_stride,
-                      int num_channels, rescaler_t* const work) {
+int WebPRescalerInit(WebPRescaler* const rescaler,
+                     int src_width, int src_height,
+                     uint8_t* const dst,
+                     int dst_width, int dst_height, int dst_stride,
+                     int num_channels, rescaler_t* const work) {
   const int x_add = src_width, x_sub = dst_width;
   const int y_add = src_height, y_sub = dst_height;
-  wrk->x_expand = (src_width < dst_width);
-  wrk->y_expand = (src_height < dst_height);
-  wrk->src_width = src_width;
-  wrk->src_height = src_height;
-  wrk->dst_width = dst_width;
-  wrk->dst_height = dst_height;
-  wrk->src_y = 0;
-  wrk->dst_y = 0;
-  wrk->dst = dst;
-  wrk->dst_stride = dst_stride;
-  wrk->num_channels = num_channels;
+  const uint64_t total_size = 2ull * dst_width * num_channels * sizeof(*work);
+  if (!CheckSizeOverflow(total_size)) return 0;
+
+  rescaler->x_expand = (src_width < dst_width);
+  rescaler->y_expand = (src_height < dst_height);
+  rescaler->src_width = src_width;
+  rescaler->src_height = src_height;
+  rescaler->dst_width = dst_width;
+  rescaler->dst_height = dst_height;
+  rescaler->src_y = 0;
+  rescaler->dst_y = 0;
+  rescaler->dst = dst;
+  rescaler->dst_stride = dst_stride;
+  rescaler->num_channels = num_channels;
 
   // for 'x_expand', we use bilinear interpolation
-  wrk->x_add = wrk->x_expand ? (x_sub - 1) : x_add;
-  wrk->x_sub = wrk->x_expand ? (x_add - 1) : x_sub;
-  if (!wrk->x_expand) {  // fx_scale is not used otherwise
-    wrk->fx_scale = WEBP_RESCALER_FRAC(1, wrk->x_sub);
+  rescaler->x_add = rescaler->x_expand ? (x_sub - 1) : x_add;
+  rescaler->x_sub = rescaler->x_expand ? (x_add - 1) : x_sub;
+  if (!rescaler->x_expand) {  // fx_scale is not used otherwise
+    rescaler->fx_scale = WEBP_RESCALER_FRAC(1, rescaler->x_sub);
   }
   // vertical scaling parameters
-  wrk->y_add = wrk->y_expand ? y_add - 1 : y_add;
-  wrk->y_sub = wrk->y_expand ? y_sub - 1 : y_sub;
-  wrk->y_accum = wrk->y_expand ? wrk->y_sub : wrk->y_add;
-  if (!wrk->y_expand) {
+  rescaler->y_add = rescaler->y_expand ? y_add - 1 : y_add;
+  rescaler->y_sub = rescaler->y_expand ? y_sub - 1 : y_sub;
+  rescaler->y_accum = rescaler->y_expand ? rescaler->y_sub : rescaler->y_add;
+  if (!rescaler->y_expand) {
     // This is WEBP_RESCALER_FRAC(dst_height, x_add * y_add) without the cast.
-    // Its value is <= WEBP_RESCALER_ONE, because dst_height <= wrk->y_add, and
-    // wrk->x_add >= 1;
-    const uint64_t ratio =
-        (uint64_t)dst_height * WEBP_RESCALER_ONE / (wrk->x_add * wrk->y_add);
+    // Its value is <= WEBP_RESCALER_ONE, because dst_height <= rescaler->y_add
+    // and rescaler->x_add >= 1;
+    const uint64_t num = (uint64_t)dst_height * WEBP_RESCALER_ONE;
+    const uint64_t den = (uint64_t)rescaler->x_add * rescaler->y_add;
+    const uint64_t ratio = num / den;
     if (ratio != (uint32_t)ratio) {
       // When ratio == WEBP_RESCALER_ONE, we can't represent the ratio with the
       // current fixed-point precision. This happens when src_height ==
-      // wrk->y_add (which == src_height), and wrk->x_add == 1.
+      // rescaler->y_add (which == src_height), and rescaler->x_add == 1.
       // => We special-case fxy_scale = 0, in WebPRescalerExportRow().
-      wrk->fxy_scale = 0;
+      rescaler->fxy_scale = 0;
     } else {
-      wrk->fxy_scale = (uint32_t)ratio;
+      rescaler->fxy_scale = (uint32_t)ratio;
     }
-    wrk->fy_scale = WEBP_RESCALER_FRAC(1, wrk->y_sub);
+    rescaler->fy_scale = WEBP_RESCALER_FRAC(1, rescaler->y_sub);
   } else {
-    wrk->fy_scale = WEBP_RESCALER_FRAC(1, wrk->x_add);
-    // wrk->fxy_scale is unused here.
+    rescaler->fy_scale = WEBP_RESCALER_FRAC(1, rescaler->x_add);
+    // rescaler->fxy_scale is unused here.
   }
-  wrk->irow = work;
-  wrk->frow = work + num_channels * dst_width;
-  memset(work, 0, 2 * dst_width * num_channels * sizeof(*work));
+  rescaler->irow = work;
+  rescaler->frow = work + num_channels * dst_width;
+  memset(work, 0, (size_t)total_size);
 
   WebPRescalerDspInit();
+  return 1;
 }
 
 int WebPRescalerGetScaledDimensions(int src_width, int src_height,
@@ -82,6 +90,7 @@ int WebPRescalerGetScaledDimensions(int src_width, int src_height,
   {
     int width = *scaled_width;
     int height = *scaled_height;
+    const int max_size = INT_MAX / 2;
 
     // if width is unspecified, scale original proportionally to height ratio.
     if (width == 0 && src_height > 0) {
@@ -94,7 +103,7 @@ int WebPRescalerGetScaledDimensions(int src_width, int src_height,
           (int)(((uint64_t)src_height * width + src_width - 1) / src_width);
     }
     // Check if the overall dimensions still make sense.
-    if (width <= 0 || height <= 0) {
+    if (width <= 0 || height <= 0 || width > max_size || height > max_size) {
       return 0;
     }
 
@@ -107,31 +116,34 @@ int WebPRescalerGetScaledDimensions(int src_width, int src_height,
 //------------------------------------------------------------------------------
 // all-in-one calls
 
-int WebPRescaleNeededLines(const WebPRescaler* const wrk, int max_num_lines) {
-  const int num_lines = (wrk->y_accum + wrk->y_sub - 1) / wrk->y_sub;
+int WebPRescaleNeededLines(const WebPRescaler* const rescaler,
+                           int max_num_lines) {
+  const int num_lines =
+      (rescaler->y_accum + rescaler->y_sub - 1) / rescaler->y_sub;
   return (num_lines > max_num_lines) ? max_num_lines : num_lines;
 }
 
-int WebPRescalerImport(WebPRescaler* const wrk, int num_lines,
+int WebPRescalerImport(WebPRescaler* const rescaler, int num_lines,
                        const uint8_t* src, int src_stride) {
   int total_imported = 0;
-  while (total_imported < num_lines && !WebPRescalerHasPendingOutput(wrk)) {
-    if (wrk->y_expand) {
-      rescaler_t* const tmp = wrk->irow;
-      wrk->irow = wrk->frow;
-      wrk->frow = tmp;
+  while (total_imported < num_lines &&
+         !WebPRescalerHasPendingOutput(rescaler)) {
+    if (rescaler->y_expand) {
+      rescaler_t* const tmp = rescaler->irow;
+      rescaler->irow = rescaler->frow;
+      rescaler->frow = tmp;
     }
-    WebPRescalerImportRow(wrk, src);
-    if (!wrk->y_expand) {     // Accumulate the contribution of the new row.
+    WebPRescalerImportRow(rescaler, src);
+    if (!rescaler->y_expand) {    // Accumulate the contribution of the new row.
       int x;
-      for (x = 0; x < wrk->num_channels * wrk->dst_width; ++x) {
-        wrk->irow[x] += wrk->frow[x];
+      for (x = 0; x < rescaler->num_channels * rescaler->dst_width; ++x) {
+        rescaler->irow[x] += rescaler->frow[x];
       }
     }
-    ++wrk->src_y;
+    ++rescaler->src_y;
     src += src_stride;
     ++total_imported;
-    wrk->y_accum -= wrk->y_sub;
+    rescaler->y_accum -= rescaler->y_sub;
   }
   return total_imported;
 }
diff --git a/thirdparty/libwebp/src/utils/rescaler_utils.h b/thirdparty/libwebp/src/utils/rescaler_utils.h
index ca41e42c4a..ef201ef86c 100644
--- a/thirdparty/libwebp/src/utils/rescaler_utils.h
+++ b/thirdparty/libwebp/src/utils/rescaler_utils.h
@@ -47,12 +47,13 @@ struct WebPRescaler {
 };
 
 // Initialize a rescaler given scratch area 'work' and dimensions of src & dst.
-void WebPRescalerInit(WebPRescaler* const rescaler,
-                      int src_width, int src_height,
-                      uint8_t* const dst,
-                      int dst_width, int dst_height, int dst_stride,
-                      int num_channels,
-                      rescaler_t* const work);
+// Returns false in case of error.
+int WebPRescalerInit(WebPRescaler* const rescaler,
+                     int src_width, int src_height,
+                     uint8_t* const dst,
+                     int dst_width, int dst_height, int dst_stride,
+                     int num_channels,
+                     rescaler_t* const work);
 
 // If either 'scaled_width' or 'scaled_height' (but not both) is 0 the value
 // will be calculated preserving the aspect ratio, otherwise the values are
diff --git a/thirdparty/libwebp/src/utils/utils.c b/thirdparty/libwebp/src/utils/utils.c
index 764f752b82..9e464c16ce 100644
--- a/thirdparty/libwebp/src/utils/utils.c
+++ b/thirdparty/libwebp/src/utils/utils.c
@@ -101,6 +101,9 @@ static void Increment(int* const v) {
 #if defined(MALLOC_LIMIT)
     {
       const char* const malloc_limit_str = getenv("MALLOC_LIMIT");
+#if MALLOC_LIMIT > 1
+      mem_limit = (size_t)MALLOC_LIMIT;
+#endif
       if (malloc_limit_str != NULL) {
         mem_limit = atoi(malloc_limit_str);
       }
@@ -169,16 +172,16 @@ static int CheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {
   const uint64_t total_size = nmemb * size;
   if (nmemb == 0) return 1;
   if ((uint64_t)size > WEBP_MAX_ALLOCABLE_MEMORY / nmemb) return 0;
-  if (total_size != (size_t)total_size) return 0;
+  if (!CheckSizeOverflow(total_size)) return 0;
 #if defined(PRINT_MEM_INFO) && defined(MALLOC_FAIL_AT)
   if (countdown_to_fail > 0 && --countdown_to_fail == 0) {
     return 0;    // fake fail!
   }
 #endif
-#if defined(MALLOC_LIMIT)
+#if defined(PRINT_MEM_INFO) && defined(MALLOC_LIMIT)
   if (mem_limit > 0) {
     const uint64_t new_total_mem = (uint64_t)total_mem + total_size;
-    if (new_total_mem != (size_t)new_total_mem ||
+    if (!CheckSizeOverflow(new_total_mem) ||
         new_total_mem > mem_limit) {
       return 0;   // fake fail!
     }
@@ -231,7 +234,7 @@ void WebPFree(void* ptr) {
 void WebPCopyPlane(const uint8_t* src, int src_stride,
                    uint8_t* dst, int dst_stride, int width, int height) {
   assert(src != NULL && dst != NULL);
-  assert(src_stride >= width && dst_stride >= width);
+  assert(abs(src_stride) >= width && abs(dst_stride) >= width);
   while (height-- > 0) {
     memcpy(dst, src, width);
     src += src_stride;
diff --git a/thirdparty/libwebp/src/utils/utils.h b/thirdparty/libwebp/src/utils/utils.h
index 2a3ec92678..ef04f108fe 100644
--- a/thirdparty/libwebp/src/utils/utils.h
+++ b/thirdparty/libwebp/src/utils/utils.h
@@ -42,6 +42,10 @@ extern "C" {
 #endif
 #endif  // WEBP_MAX_ALLOCABLE_MEMORY
 
+static WEBP_INLINE int CheckSizeOverflow(uint64_t size) {
+  return size == (size_t)size;
+}
+
 // size-checking safe malloc/calloc: verify that the requested size is not too
 // large, or return NULL. You don't need to call these for constructs like
 // malloc(sizeof(foo)), but only if there's picture-dependent size involved
@@ -107,24 +111,33 @@ static WEBP_INLINE void PutLE32(uint8_t* const data, uint32_t val) {
   PutLE16(data + 2, (int)(val >> 16));
 }
 
-// Returns (int)floor(log2(n)). n must be > 0.
 // use GNU builtins where available.
 #if defined(__GNUC__) && \
     ((__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || __GNUC__ >= 4)
+// Returns (int)floor(log2(n)). n must be > 0.
 static WEBP_INLINE int BitsLog2Floor(uint32_t n) {
   return 31 ^ __builtin_clz(n);
 }
+// counts the number of trailing zero
+static WEBP_INLINE int BitsCtz(uint32_t n) { return __builtin_ctz(n); }
 #elif defined(_MSC_VER) && _MSC_VER > 1310 && \
       (defined(_M_X64) || defined(_M_IX86))
 #include <intrin.h>
 #pragma intrinsic(_BitScanReverse)
+#pragma intrinsic(_BitScanForward)
 
 static WEBP_INLINE int BitsLog2Floor(uint32_t n) {
-  unsigned long first_set_bit;
+  unsigned long first_set_bit;  // NOLINT (runtime/int)
   _BitScanReverse(&first_set_bit, n);
   return first_set_bit;
 }
-#else   // default: use the C-version.
+static WEBP_INLINE int BitsCtz(uint32_t n) {
+  unsigned long first_set_bit;  // NOLINT (runtime/int)
+  _BitScanForward(&first_set_bit, n);
+  return first_set_bit;
+}
+#else   // default: use the (slow) C-version.
+#define WEBP_HAVE_SLOW_CLZ_CTZ   // signal that the Clz/Ctz function are slow
 // Returns 31 ^ clz(n) = log2(n). This is the default C-implementation, either
 // based on table or not. Can be used as fallback if clz() is not available.
 #define WEBP_NEED_LOG_TABLE_8BIT
@@ -139,6 +152,15 @@ static WEBP_INLINE int WebPLog2FloorC(uint32_t n) {
 }
 
 static WEBP_INLINE int BitsLog2Floor(uint32_t n) { return WebPLog2FloorC(n); }
+
+static WEBP_INLINE int BitsCtz(uint32_t n) {
+  int i;
+  for (i = 0; i < 32; ++i, n >>= 1) {
+    if (n & 1) return i;
+  }
+  return 32;
+}
+
 #endif
 
 //------------------------------------------------------------------------------
diff --git a/thirdparty/libwebp/src/webp/decode.h b/thirdparty/libwebp/src/webp/decode.h
index 80dd0ef0cc..44fcd64a84 100644
--- a/thirdparty/libwebp/src/webp/decode.h
+++ b/thirdparty/libwebp/src/webp/decode.h
@@ -453,7 +453,7 @@ struct WebPDecoderOptions {
   int scaled_width, scaled_height;    // final resolution
   int use_threads;                    // if true, use multi-threaded decoding
   int dithering_strength;             // dithering strength (0=Off, 100=full)
-  int flip;                           // flip output vertically
+  int flip;                           // if true, flip output vertically
   int alpha_dithering_strength;       // alpha dithering strength in [0..100]
 
   uint32_t pad[5];                    // padding for later use
diff --git a/thirdparty/libwebp/src/webp/encode.h b/thirdparty/libwebp/src/webp/encode.h
index 655166e7d4..b4c599df87 100644
--- a/thirdparty/libwebp/src/webp/encode.h
+++ b/thirdparty/libwebp/src/webp/encode.h
@@ -148,7 +148,8 @@ struct WebPConfig {
   int use_delta_palette;  // reserved for future lossless feature
   int use_sharp_yuv;      // if needed, use sharp (and slow) RGB->YUV conversion
 
-  uint32_t pad[2];        // padding for later use
+  int qmin;               // minimum permissible quality factor
+  int qmax;               // maximum permissible quality factor
 };
 
 // Enumerate some predefined settings for WebPConfig, depending on the type
@@ -291,6 +292,11 @@ typedef enum WebPEncodingError {
 #define WEBP_MAX_DIMENSION 16383
 
 // Main exchange structure (input samples, output bytes, statistics)
+//
+// Once WebPPictureInit() has been called, it's ok to make all the INPUT fields
+// (use_argb, y/u/v, argb, ...) point to user-owned data, even if
+// WebPPictureAlloc() has been called. Depending on the value use_argb,
+// it's guaranteed that either *argb or *y/*u/*v content will be kept untouched.
 struct WebPPicture {
   //   INPUT
   //////////////