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authorRĂ©mi Verschelde <rverschelde@gmail.com>2017-12-12 00:14:26 +0100
committerGitHub <noreply@github.com>2017-12-12 00:14:26 +0100
commit3a078603112710d1d2719d7919711ab76ae161f0 (patch)
treef01b1d94887864387026e2955b9a69b7dd10318c /thirdparty/libwebp/src/dec/io_dec.c
parent33db6a14df19a8d3feecac5d4254699c34625fc1 (diff)
parent043103fe6a1168729abf74dd56b8982ce54eea43 (diff)
Merge pull request #14561 from volzhs/libwebp-0.6.1
Update libwebp to 0.6.1
Diffstat (limited to 'thirdparty/libwebp/src/dec/io_dec.c')
-rw-r--r--thirdparty/libwebp/src/dec/io_dec.c649
1 files changed, 649 insertions, 0 deletions
diff --git a/thirdparty/libwebp/src/dec/io_dec.c b/thirdparty/libwebp/src/dec/io_dec.c
new file mode 100644
index 0000000000..e603f19c98
--- /dev/null
+++ b/thirdparty/libwebp/src/dec/io_dec.c
@@ -0,0 +1,649 @@
+// Copyright 2011 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.
+// -----------------------------------------------------------------------------
+//
+// functions for sample output.
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#include <assert.h>
+#include <stdlib.h>
+#include "src/dec/vp8i_dec.h"
+#include "src/dec/webpi_dec.h"
+#include "src/dsp/dsp.h"
+#include "src/dsp/yuv.h"
+#include "src/utils/utils.h"
+
+//------------------------------------------------------------------------------
+// Main YUV<->RGB conversion functions
+
+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;
+ 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);
+ }
+ return io->mb_h;
+}
+
+// Point-sampling U/V sampler.
+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;
+ WebPSamplerProcessPlane(io->y, io->y_stride,
+ io->u, io->v, io->uv_stride,
+ dst, buf->stride, io->mb_w, io->mb_h,
+ WebPSamplers[output->colorspace]);
+ return io->mb_h;
+}
+
+//------------------------------------------------------------------------------
+// Fancy upsampling
+
+#ifdef FANCY_UPSAMPLING
+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;
+ WebPUpsampleLinePairFunc upsample = WebPUpsamplers[p->output->colorspace];
+ const uint8_t* cur_y = io->y;
+ const uint8_t* cur_u = io->u;
+ const uint8_t* cur_v = io->v;
+ const uint8_t* top_u = p->tmp_u;
+ const uint8_t* top_v = p->tmp_v;
+ int y = io->mb_y;
+ const int y_end = io->mb_y + io->mb_h;
+ const int mb_w = io->mb_w;
+ const int uv_w = (mb_w + 1) / 2;
+
+ if (y == 0) {
+ // First line is special cased. We mirror the u/v samples at boundary.
+ upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v, dst, NULL, mb_w);
+ } else {
+ // We can finish the left-over line from previous call.
+ upsample(p->tmp_y, cur_y, top_u, top_v, cur_u, cur_v,
+ dst - buf->stride, dst, mb_w);
+ ++num_lines_out;
+ }
+ // Loop over each output pairs of row.
+ for (; y + 2 < y_end; y += 2) {
+ top_u = cur_u;
+ top_v = cur_v;
+ cur_u += io->uv_stride;
+ cur_v += io->uv_stride;
+ dst += 2 * buf->stride;
+ cur_y += 2 * io->y_stride;
+ upsample(cur_y - io->y_stride, cur_y,
+ top_u, top_v, cur_u, cur_v,
+ dst - buf->stride, dst, mb_w);
+ }
+ // move to last row
+ cur_y += io->y_stride;
+ if (io->crop_top + y_end < io->crop_bottom) {
+ // Save the unfinished samples for next call (as we're not done yet).
+ memcpy(p->tmp_y, cur_y, mb_w * sizeof(*p->tmp_y));
+ memcpy(p->tmp_u, cur_u, uv_w * sizeof(*p->tmp_u));
+ memcpy(p->tmp_v, cur_v, uv_w * sizeof(*p->tmp_v));
+ // The fancy upsampler leaves a row unfinished behind
+ // (except for the very last row)
+ num_lines_out--;
+ } else {
+ // Process the very last row of even-sized picture
+ if (!(y_end & 1)) {
+ upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v,
+ dst + buf->stride, NULL, mb_w);
+ }
+ }
+ return num_lines_out;
+}
+
+#endif /* FANCY_UPSAMPLING */
+
+//------------------------------------------------------------------------------
+
+static void FillAlphaPlane(uint8_t* dst, int w, int h, int stride) {
+ int j;
+ for (j = 0; j < h; ++j) {
+ memset(dst, 0xff, w * sizeof(*dst));
+ dst += stride;
+ }
+}
+
+static int EmitAlphaYUV(const VP8Io* const io, WebPDecParams* const p,
+ int expected_num_lines_out) {
+ const uint8_t* alpha = io->a;
+ 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;
+ int j;
+ (void)expected_num_lines_out;
+ assert(expected_num_lines_out == mb_h);
+ if (alpha != NULL) {
+ for (j = 0; j < mb_h; ++j) {
+ memcpy(dst, alpha, mb_w * sizeof(*dst));
+ alpha += io->width;
+ dst += buf->a_stride;
+ }
+ } else if (buf->a != NULL) {
+ // the user requested alpha, but there is none, set it to opaque.
+ FillAlphaPlane(dst, mb_w, mb_h, buf->a_stride);
+ }
+ return 0;
+}
+
+static int GetAlphaSourceRow(const VP8Io* const io,
+ const uint8_t** alpha, int* const num_rows) {
+ int start_y = io->mb_y;
+ *num_rows = io->mb_h;
+
+ // Compensate for the 1-line delay of the fancy upscaler.
+ // This is similar to EmitFancyRGB().
+ if (io->fancy_upsampling) {
+ if (start_y == 0) {
+ // We don't process the last row yet. It'll be done during the next call.
+ --*num_rows;
+ } else {
+ --start_y;
+ // Fortunately, *alpha data is persistent, so we can go back
+ // one row and finish alpha blending, now that the fancy upscaler
+ // completed the YUV->RGB interpolation.
+ *alpha -= io->width;
+ }
+ if (io->crop_top + io->mb_y + io->mb_h == io->crop_bottom) {
+ // If it's the very last call, we process all the remaining rows!
+ *num_rows = io->crop_bottom - io->crop_top - start_y;
+ }
+ }
+ return start_y;
+}
+
+static int EmitAlphaRGB(const VP8Io* const io, WebPDecParams* const p,
+ int expected_num_lines_out) {
+ const uint8_t* alpha = io->a;
+ if (alpha != NULL) {
+ const int mb_w = io->mb_w;
+ const WEBP_CSP_MODE colorspace = p->output->colorspace;
+ const int alpha_first =
+ (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);
+ 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,
+ num_rows, dst, buf->stride);
+ (void)expected_num_lines_out;
+ assert(expected_num_lines_out == num_rows);
+ // has_alpha is true if there's non-trivial alpha to premultiply with.
+ if (has_alpha && WebPIsPremultipliedMode(colorspace)) {
+ WebPApplyAlphaMultiply(base_rgba, alpha_first,
+ mb_w, num_rows, buf->stride);
+ }
+ }
+ return 0;
+}
+
+static int EmitAlphaRGBA4444(const VP8Io* const io, WebPDecParams* const p,
+ int expected_num_lines_out) {
+ const uint8_t* alpha = io->a;
+ if (alpha != NULL) {
+ const int mb_w = io->mb_w;
+ 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);
+ uint8_t* const base_rgba = buf->rgba + start_y * buf->stride;
+#if (WEBP_SWAP_16BIT_CSP == 1)
+ uint8_t* alpha_dst = base_rgba;
+#else
+ uint8_t* alpha_dst = base_rgba + 1;
+#endif
+ uint32_t alpha_mask = 0x0f;
+ int i, j;
+ for (j = 0; j < num_rows; ++j) {
+ for (i = 0; i < mb_w; ++i) {
+ // Fill in the alpha value (converted to 4 bits).
+ const uint32_t alpha_value = alpha[i] >> 4;
+ alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value;
+ alpha_mask &= alpha_value;
+ }
+ alpha += io->width;
+ alpha_dst += buf->stride;
+ }
+ (void)expected_num_lines_out;
+ assert(expected_num_lines_out == num_rows);
+ if (alpha_mask != 0x0f && WebPIsPremultipliedMode(colorspace)) {
+ WebPApplyAlphaMultiply4444(base_rgba, mb_w, num_rows, buf->stride);
+ }
+ }
+ return 0;
+}
+
+//------------------------------------------------------------------------------
+// YUV rescaling (no final RGB conversion needed)
+
+#if !defined(WEBP_REDUCE_SIZE)
+static int Rescale(const uint8_t* src, int src_stride,
+ int new_lines, WebPRescaler* const wrk) {
+ int num_lines_out = 0;
+ while (new_lines > 0) { // import new contributions of source rows.
+ const int lines_in = WebPRescalerImport(wrk, new_lines, src, src_stride);
+ src += lines_in * src_stride;
+ new_lines -= lines_in;
+ num_lines_out += WebPRescalerExport(wrk); // emit output row(s)
+ }
+ return num_lines_out;
+}
+
+static int EmitRescaledYUV(const VP8Io* const io, WebPDecParams* const p) {
+ const int mb_h = io->mb_h;
+ const int uv_mb_h = (mb_h + 1) >> 1;
+ WebPRescaler* const scaler = p->scaler_y;
+ int num_lines_out = 0;
+ if (WebPIsAlphaMode(p->output->colorspace) && io->a != NULL) {
+ // Before rescaling, we premultiply the luma directly into the io->y
+ // internal buffer. This is OK since these samples are not used for
+ // intra-prediction (the top samples are saved in cache_y_/u_/v_).
+ // But we need to cast the const away, though.
+ WebPMultRows((uint8_t*)io->y, io->y_stride,
+ io->a, io->width, io->mb_w, mb_h, 0);
+ }
+ num_lines_out = Rescale(io->y, io->y_stride, mb_h, scaler);
+ Rescale(io->u, io->uv_stride, uv_mb_h, p->scaler_u);
+ Rescale(io->v, io->uv_stride, uv_mb_h, p->scaler_v);
+ return num_lines_out;
+}
+
+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;
+ if (io->a != NULL) {
+ uint8_t* const dst_y = buf->y + 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
+ WebPMultRows(dst_y, buf->y_stride, dst_a, buf->a_stride,
+ p->scaler_a->dst_width, num_lines_out, 1);
+ }
+ } else if (buf->a != NULL) {
+ // the user requested alpha, but there is none, set it to opaque.
+ assert(p->last_y + expected_num_lines_out <= io->scaled_height);
+ FillAlphaPlane(dst_a, io->scaled_width, expected_num_lines_out,
+ buf->a_stride);
+ }
+ return 0;
+}
+
+static int InitYUVRescaler(const VP8Io* const io, WebPDecParams* const p) {
+ const int has_alpha = WebPIsAlphaMode(p->output->colorspace);
+ const WebPYUVABuffer* const buf = &p->output->u.YUVA;
+ const int out_width = io->scaled_width;
+ const int out_height = io->scaled_height;
+ const int uv_out_width = (out_width + 1) >> 1;
+ 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
+ const size_t uv_work_size = 2 * uv_out_width; // and for each u/v ones
+ size_t tmp_size, 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);
+ if (has_alpha) {
+ tmp_size += work_size * sizeof(*work);
+ }
+ rescaler_size = num_rescalers * sizeof(*p->scaler_y) + WEBP_ALIGN_CST;
+
+ p->memory = WebPSafeMalloc(1ULL, tmp_size + rescaler_size);
+ if (p->memory == NULL) {
+ return 0; // memory error
+ }
+ work = (rescaler_t*)p->memory;
+
+ scalers = (WebPRescaler*)WEBP_ALIGN((const uint8_t*)work + tmp_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);
+ 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);
+ p->emit_alpha = EmitRescaledAlphaYUV;
+ WebPInitAlphaProcessing();
+ }
+ return 1;
+}
+
+//------------------------------------------------------------------------------
+// RGBA rescaling
+
+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;
+ 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.
+ while (WebPRescalerHasPendingOutput(p->scaler_y) &&
+ WebPRescalerHasPendingOutput(p->scaler_u)) {
+ assert(y_pos + num_lines_out < p->output->height);
+ assert(p->scaler_u->y_accum == p->scaler_v->y_accum);
+ WebPRescalerExportRow(p->scaler_y);
+ WebPRescalerExportRow(p->scaler_u);
+ WebPRescalerExportRow(p->scaler_v);
+ convert(p->scaler_y->dst, p->scaler_u->dst, p->scaler_v->dst,
+ dst, p->scaler_y->dst_width);
+ dst += buf->stride;
+ ++num_lines_out;
+ }
+ return num_lines_out;
+}
+
+static int EmitRescaledRGB(const VP8Io* const io, WebPDecParams* const p) {
+ const int mb_h = io->mb_h;
+ const int uv_mb_h = (mb_h + 1) >> 1;
+ int j = 0, uv_j = 0;
+ int num_lines_out = 0;
+ 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);
+ 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);
+ (void)v_lines_in; // remove a gcc warning
+ assert(u_lines_in == v_lines_in);
+ uv_j += u_lines_in;
+ }
+ num_lines_out += ExportRGB(p, p->last_y + num_lines_out);
+ }
+ return num_lines_out;
+}
+
+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;
+ const WEBP_CSP_MODE colorspace = p->output->colorspace;
+ const int alpha_first =
+ (colorspace == MODE_ARGB || colorspace == MODE_Argb);
+ uint8_t* dst = base_rgba + (alpha_first ? 0 : 3);
+ int num_lines_out = 0;
+ const int is_premult_alpha = WebPIsPremultipliedMode(colorspace);
+ uint32_t non_opaque = 0;
+ const int width = p->scaler_a->dst_width;
+
+ while (WebPRescalerHasPendingOutput(p->scaler_a) &&
+ num_lines_out < max_lines_out) {
+ assert(y_pos + num_lines_out < p->output->height);
+ WebPRescalerExportRow(p->scaler_a);
+ non_opaque |= WebPDispatchAlpha(p->scaler_a->dst, 0, width, 1, dst, 0);
+ dst += buf->stride;
+ ++num_lines_out;
+ }
+ if (is_premult_alpha && non_opaque) {
+ WebPApplyAlphaMultiply(base_rgba, alpha_first,
+ width, num_lines_out, buf->stride);
+ }
+ return num_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;
+#if (WEBP_SWAP_16BIT_CSP == 1)
+ uint8_t* alpha_dst = base_rgba;
+#else
+ uint8_t* alpha_dst = base_rgba + 1;
+#endif
+ int num_lines_out = 0;
+ const WEBP_CSP_MODE colorspace = p->output->colorspace;
+ const int width = p->scaler_a->dst_width;
+ const int is_premult_alpha = WebPIsPremultipliedMode(colorspace);
+ uint32_t alpha_mask = 0x0f;
+
+ while (WebPRescalerHasPendingOutput(p->scaler_a) &&
+ num_lines_out < max_lines_out) {
+ int i;
+ assert(y_pos + num_lines_out < p->output->height);
+ WebPRescalerExportRow(p->scaler_a);
+ for (i = 0; i < width; ++i) {
+ // Fill in the alpha value (converted to 4 bits).
+ const uint32_t alpha_value = p->scaler_a->dst[i] >> 4;
+ alpha_dst[2 * i] = (alpha_dst[2 * i] & 0xf0) | alpha_value;
+ alpha_mask &= alpha_value;
+ }
+ alpha_dst += buf->stride;
+ ++num_lines_out;
+ }
+ if (is_premult_alpha && alpha_mask != 0x0f) {
+ WebPApplyAlphaMultiply4444(base_rgba, width, num_lines_out, buf->stride);
+ }
+ return num_lines_out;
+}
+
+static int EmitRescaledAlphaRGB(const VP8Io* const io, WebPDecParams* const p,
+ int expected_num_out_lines) {
+ if (io->a != NULL) {
+ WebPRescaler* const scaler = p->scaler_a;
+ 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;
+ 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);
+ }
+ }
+ return 0;
+}
+
+static int InitRGBRescaler(const VP8Io* const io, WebPDecParams* const p) {
+ const int has_alpha = WebPIsAlphaMode(p->output->colorspace);
+ const int out_width = io->scaled_width;
+ 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
+ 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;
+ 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;
+ }
+ total_size = tmp_size1 * sizeof(*work) + tmp_size2 * sizeof(*tmp);
+ rescaler_size = num_rescalers * sizeof(*p->scaler_y) + WEBP_ALIGN_CST;
+
+ p->memory = WebPSafeMalloc(1ULL, total_size + rescaler_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);
+ 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);
+ 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);
+ p->emit_alpha = EmitRescaledAlphaRGB;
+ if (p->output->colorspace == MODE_RGBA_4444 ||
+ p->output->colorspace == MODE_rgbA_4444) {
+ p->emit_alpha_row = ExportAlphaRGBA4444;
+ } else {
+ p->emit_alpha_row = ExportAlpha;
+ }
+ WebPInitAlphaProcessing();
+ }
+ return 1;
+}
+
+#endif // WEBP_REDUCE_SIZE
+
+//------------------------------------------------------------------------------
+// Default custom functions
+
+static int CustomSetup(VP8Io* io) {
+ WebPDecParams* const p = (WebPDecParams*)io->opaque;
+ const WEBP_CSP_MODE colorspace = p->output->colorspace;
+ const int is_rgb = WebPIsRGBMode(colorspace);
+ const int is_alpha = WebPIsAlphaMode(colorspace);
+
+ p->memory = NULL;
+ p->emit = NULL;
+ p->emit_alpha = NULL;
+ p->emit_alpha_row = NULL;
+ if (!WebPIoInitFromOptions(p->options, io, is_alpha ? MODE_YUV : MODE_YUVA)) {
+ return 0;
+ }
+ if (is_alpha && WebPIsPremultipliedMode(colorspace)) {
+ WebPInitUpsamplers();
+ }
+ if (io->use_scaling) {
+#if !defined(WEBP_REDUCE_SIZE)
+ const int ok = is_rgb ? InitRGBRescaler(io, p) : InitYUVRescaler(io, p);
+ if (!ok) {
+ return 0; // memory error
+ }
+#else
+ return 0; // rescaling support not compiled
+#endif
+ } else {
+ if (is_rgb) {
+ WebPInitSamplers();
+ p->emit = EmitSampledRGB; // default
+ if (io->fancy_upsampling) {
+#ifdef FANCY_UPSAMPLING
+ const int uv_width = (io->mb_w + 1) >> 1;
+ p->memory = WebPSafeMalloc(1ULL, (size_t)(io->mb_w + 2 * uv_width));
+ if (p->memory == NULL) {
+ return 0; // memory error.
+ }
+ p->tmp_y = (uint8_t*)p->memory;
+ p->tmp_u = p->tmp_y + io->mb_w;
+ p->tmp_v = p->tmp_u + uv_width;
+ p->emit = EmitFancyRGB;
+ WebPInitUpsamplers();
+#endif
+ }
+ } else {
+ p->emit = EmitYUV;
+ }
+ if (is_alpha) { // need transparency output
+ p->emit_alpha =
+ (colorspace == MODE_RGBA_4444 || colorspace == MODE_rgbA_4444) ?
+ EmitAlphaRGBA4444
+ : is_rgb ? EmitAlphaRGB
+ : EmitAlphaYUV;
+ if (is_rgb) {
+ WebPInitAlphaProcessing();
+ }
+ }
+ }
+
+ return 1;
+}
+
+//------------------------------------------------------------------------------
+
+static int CustomPut(const VP8Io* io) {
+ WebPDecParams* const p = (WebPDecParams*)io->opaque;
+ const int mb_w = io->mb_w;
+ const int mb_h = io->mb_h;
+ int num_lines_out;
+ assert(!(io->mb_y & 1));
+
+ if (mb_w <= 0 || mb_h <= 0) {
+ return 0;
+ }
+ num_lines_out = p->emit(io, p);
+ if (p->emit_alpha != NULL) {
+ p->emit_alpha(io, p, num_lines_out);
+ }
+ p->last_y += num_lines_out;
+ return 1;
+}
+
+//------------------------------------------------------------------------------
+
+static void CustomTeardown(const VP8Io* io) {
+ WebPDecParams* const p = (WebPDecParams*)io->opaque;
+ WebPSafeFree(p->memory);
+ p->memory = NULL;
+}
+
+//------------------------------------------------------------------------------
+// Main entry point
+
+void WebPInitCustomIo(WebPDecParams* const params, VP8Io* const io) {
+ io->put = CustomPut;
+ io->setup = CustomSetup;
+ io->teardown = CustomTeardown;
+ io->opaque = params;
+}
+
+//------------------------------------------------------------------------------