Update libwebp to 0.6.1

* lossless performance and compression improvements + a new 'cruncher' mode (-m 6 -q 100)
* ARM performance improvements with clang (15-20% w/ndk r15c)
* webp-js: emscripten/webassembly based javascript decoder
* miscellaneous bug & build fixes

1 files changed, 152 insertions, 0 deletions

diff --git a/thirdparty/libwebp/src/enc/config_enc.c b/thirdparty/libwebp/src/enc/config_enc.c
new file mode 100644
index 0000000000..9d4828978e
--- /dev/null
+++ b/thirdparty/libwebp/src/enc/config_enc.c
@@ -0,0 +1,152 @@
+// 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.
+// -----------------------------------------------------------------------------
+//
+// Coding tools configuration
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#ifdef HAVE_CONFIG_H
+#include "src/webp/config.h"
+#endif
+
+#include "src/webp/encode.h"
+
+//------------------------------------------------------------------------------
+// WebPConfig
+//------------------------------------------------------------------------------
+
+int WebPConfigInitInternal(WebPConfig* config,
+                           WebPPreset preset, float quality, int version) {
+  if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_ENCODER_ABI_VERSION)) {
+    return 0;   // caller/system version mismatch!
+  }
+  if (config == NULL) return 0;
+
+  config->quality = quality;
+  config->target_size = 0;
+  config->target_PSNR = 0.;
+  config->method = 4;
+  config->sns_strength = 50;
+  config->filter_strength = 60;   // mid-filtering
+  config->filter_sharpness = 0;
+  config->filter_type = 1;        // default: strong (so U/V is filtered too)
+  config->partitions = 0;
+  config->segments = 4;
+  config->pass = 1;
+  config->show_compressed = 0;
+  config->preprocessing = 0;
+  config->autofilter = 0;
+  config->partition_limit = 0;
+  config->alpha_compression = 1;
+  config->alpha_filtering = 1;
+  config->alpha_quality = 100;
+  config->lossless = 0;
+  config->exact = 0;
+  config->image_hint = WEBP_HINT_DEFAULT;
+  config->emulate_jpeg_size = 0;
+  config->thread_level = 0;
+  config->low_memory = 0;
+  config->near_lossless = 100;
+  config->use_delta_palette = 0;
+  config->use_sharp_yuv = 0;
+
+  // TODO(skal): tune.
+  switch (preset) {
+    case WEBP_PRESET_PICTURE:
+      config->sns_strength = 80;
+      config->filter_sharpness = 4;
+      config->filter_strength = 35;
+      config->preprocessing &= ~2;   // no dithering
+      break;
+    case WEBP_PRESET_PHOTO:
+      config->sns_strength = 80;
+      config->filter_sharpness = 3;
+      config->filter_strength = 30;
+      config->preprocessing |= 2;
+      break;
+    case WEBP_PRESET_DRAWING:
+      config->sns_strength = 25;
+      config->filter_sharpness = 6;
+      config->filter_strength = 10;
+      break;
+    case WEBP_PRESET_ICON:
+      config->sns_strength = 0;
+      config->filter_strength = 0;   // disable filtering to retain sharpness
+      config->preprocessing &= ~2;   // no dithering
+      break;
+    case WEBP_PRESET_TEXT:
+      config->sns_strength = 0;
+      config->filter_strength = 0;   // disable filtering to retain sharpness
+      config->preprocessing &= ~2;   // no dithering
+      config->segments = 2;
+      break;
+    case WEBP_PRESET_DEFAULT:
+    default:
+      break;
+  }
+  return WebPValidateConfig(config);
+}
+
+int WebPValidateConfig(const WebPConfig* config) {
+  if (config == NULL) return 0;
+  if (config->quality < 0 || config->quality > 100) return 0;
+  if (config->target_size < 0) return 0;
+  if (config->target_PSNR < 0) return 0;
+  if (config->method < 0 || config->method > 6) return 0;
+  if (config->segments < 1 || config->segments > 4) return 0;
+  if (config->sns_strength < 0 || config->sns_strength > 100) return 0;
+  if (config->filter_strength < 0 || config->filter_strength > 100) return 0;
+  if (config->filter_sharpness < 0 || config->filter_sharpness > 7) return 0;
+  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->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;
+  if (config->partition_limit < 0 || config->partition_limit > 100) return 0;
+  if (config->alpha_compression < 0) return 0;
+  if (config->alpha_filtering < 0) return 0;
+  if (config->alpha_quality < 0 || config->alpha_quality > 100) return 0;
+  if (config->lossless < 0 || config->lossless > 1) return 0;
+  if (config->near_lossless < 0 || config->near_lossless > 100) return 0;
+  if (config->image_hint >= WEBP_HINT_LAST) return 0;
+  if (config->emulate_jpeg_size < 0 || config->emulate_jpeg_size > 1) return 0;
+  if (config->thread_level < 0 || config->thread_level > 1) return 0;
+  if (config->low_memory < 0 || config->low_memory > 1) return 0;
+  if (config->exact < 0 || config->exact > 1) return 0;
+  if (config->use_delta_palette < 0 || config->use_delta_palette > 1) {
+    return 0;
+  }
+  if (config->use_sharp_yuv < 0 || config->use_sharp_yuv > 1) return 0;
+
+  return 1;
+}
+
+//------------------------------------------------------------------------------
+
+#define MAX_LEVEL 9
+
+// Mapping between -z level and -m / -q parameter settings.
+static const struct {
+  uint8_t method_;
+  uint8_t quality_;
+} kLosslessPresets[MAX_LEVEL + 1] = {
+  { 0,  0 }, { 1, 20 }, { 2, 25 }, { 3, 30 }, { 3, 50 },
+  { 4, 50 }, { 4, 75 }, { 4, 90 }, { 5, 90 }, { 6, 100 }
+};
+
+int WebPConfigLosslessPreset(WebPConfig* config, int level) {
+  if (config == NULL || level < 0 || level > MAX_LEVEL) return 0;
+  config->lossless = 1;
+  config->method = kLosslessPresets[level].method_;
+  config->quality = kLosslessPresets[level].quality_;
+  return 1;
+}
+
+//------------------------------------------------------------------------------