libwebp-0.3.1

Bug fix rollup + incremental decode support for extended format files
(alpha/icc + vp8).

BUG=

Review URL: https://chromiumcodereview.appspot.com/16871017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@207471 0039d316-1c4b-4281-b951-d872f2087c98

22 files changed, 268 insertions, 167 deletions

diff --git a/third_party/libwebp/enc/alpha.c b/third_party/libwebp/enc/alpha.c
index aadf88f..e636c96 100644
--- a/third_party/libwebp/enc/alpha.c
+++ b/third_party/libwebp/enc/alpha.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Alpha-plane compression.
@@ -80,7 +82,7 @@ static int EncodeLossless(const uint8_t* const data, int width, int height,
   config.lossless = 1;
   config.method = effort_level;  // impact is very small
   // Set a moderate default quality setting for alpha.
-  config.quality = 5.f * effort_level;
+  config.quality = 10.f * effort_level;
   assert(config.quality >= 0 && config.quality <= 100.f);
 
   ok = VP8LBitWriterInit(&tmp_bw, (width * height) >> 3);
@@ -156,6 +158,25 @@ static void CopyPlane(const uint8_t* src, int src_stride,
   }
 }
 
+static int GetNumColors(const uint8_t* data, int width, int height,
+                        int stride) {
+  int j;
+  int colors = 0;
+  uint8_t color[256] = { 0 };
+
+  for (j = 0; j < height; ++j) {
+    int i;
+    const uint8_t* const p = data + j * stride;
+    for (i = 0; i < width; ++i) {
+      color[p[i]] = 1;
+    }
+  }
+  for (j = 0; j < 256; ++j) {
+    if (color[j] > 0) ++colors;
+  }
+  return colors;
+}
+
 static int EncodeAlpha(VP8Encoder* const enc,
                        int quality, int method, int filter,
                        int effort_level,
@@ -207,18 +228,32 @@ static int EncodeAlpha(VP8Encoder* const enc,
     VP8BitWriter bw;
     int test_filter;
     uint8_t* filtered_alpha = NULL;
-
-    // We always test WEBP_FILTER_NONE first.
-    ok = EncodeAlphaInternal(quant_alpha, width, height,
-                             method, WEBP_FILTER_NONE, reduce_levels,
-                             effort_level, NULL, &bw, pic->stats);
-    if (!ok) {
-      VP8BitWriterWipeOut(&bw);
-      goto End;
+    int try_filter_none = (effort_level > 3);
+
+    if (filter == WEBP_FILTER_FAST) {  // Quick estimate of the best candidate.
+      const int kMinColorsForFilterNone = 16;
+      const int kMaxColorsForFilterNone = 192;
+      const int num_colors = GetNumColors(quant_alpha, width, height, width);
+      // For low number of colors, NONE yeilds better compression.
+      filter = (num_colors <= kMinColorsForFilterNone) ? WEBP_FILTER_NONE :
+               EstimateBestFilter(quant_alpha, width, height, width);
+      // For large number of colors, try FILTER_NONE in addition to the best
+      // filter as well.
+      if (num_colors > kMaxColorsForFilterNone) {
+        try_filter_none = 1;
+      }
     }
 
-    if (filter == WEBP_FILTER_FAST) {  // Quick estimate of a second candidate?
-      filter = EstimateBestFilter(quant_alpha, width, height, width);
+    // Test for WEBP_FILTER_NONE for higher effort levels.
+    if (try_filter_none || filter == WEBP_FILTER_NONE) {
+      ok = EncodeAlphaInternal(quant_alpha, width, height,
+                               method, WEBP_FILTER_NONE, reduce_levels,
+                               effort_level, NULL, &bw, pic->stats);
+
+      if (!ok) {
+        VP8BitWriterWipeOut(&bw);
+        goto End;
+      }
     }
     // Stop?
     if (filter == WEBP_FILTER_NONE) {
@@ -234,11 +269,14 @@ static int EncodeAlpha(VP8Encoder* const enc,
     // Try the other mode(s).
     {
       WebPAuxStats best_stats;
-      size_t best_score = VP8BitWriterSize(&bw);
+      size_t best_score = try_filter_none ?
+                          VP8BitWriterSize(&bw) : (size_t)~0U;
+      int wipe_tmp_bw = try_filter_none;
 
       memset(&best_stats, 0, sizeof(best_stats));  // prevent spurious warning
       if (pic->stats != NULL) best_stats = *pic->stats;
-      for (test_filter = WEBP_FILTER_HORIZONTAL;
+      for (test_filter =
+           try_filter_none ? WEBP_FILTER_HORIZONTAL : WEBP_FILTER_NONE;
            ok && (test_filter <= WEBP_FILTER_GRADIENT);
            ++test_filter) {
         VP8BitWriter tmp_bw;
@@ -262,7 +300,10 @@ static int EncodeAlpha(VP8Encoder* const enc,
         } else {
           VP8BitWriterWipeOut(&bw);
         }
-        VP8BitWriterWipeOut(&tmp_bw);
+        if (wipe_tmp_bw) {
+          VP8BitWriterWipeOut(&tmp_bw);
+        }
+        wipe_tmp_bw = 1;  // For next filter trial for WEBP_FILTER_BEST.
       }
       if (pic->stats != NULL) *pic->stats = best_stats;
     }
diff --git a/third_party/libwebp/enc/analysis.c b/third_party/libwebp/enc/analysis.c
index 221e9d0..4ff3edd 100644
--- a/third_party/libwebp/enc/analysis.c
+++ b/third_party/libwebp/enc/analysis.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Macroblock analysis
diff --git a/third_party/libwebp/enc/backward_references.c b/third_party/libwebp/enc/backward_references.c
index cf02787..db4f430 100644
--- a/third_party/libwebp/enc/backward_references.c
+++ b/third_party/libwebp/enc/backward_references.c
@@ -1,8 +1,10 @@
 // Copyright 2012 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Author: Jyrki Alakuijala (jyrki@google.com)
@@ -142,9 +144,10 @@ static void HashChainInsert(HashChain* const p,
 }
 
 static void GetParamsForHashChainFindCopy(int quality, int xsize,
-                                          int* window_size, int* iter_pos,
-                                          int* iter_limit) {
+                                          int cache_bits, int* window_size,
+                                          int* iter_pos, int* iter_limit) {
   const int iter_mult = (quality < 27) ? 1 : 1 + ((quality - 27) >> 4);
+  const int iter_neg = -iter_mult * (quality >> 1);
   // Limit the backward-ref window size for lower qualities.
   const int max_window_size = (quality > 50) ? WINDOW_SIZE
                             : (quality > 25) ? (xsize << 8)
@@ -152,77 +155,74 @@ static void GetParamsForHashChainFindCopy(int quality, int xsize,
   assert(xsize > 0);
   *window_size = (max_window_size > WINDOW_SIZE) ? WINDOW_SIZE
                : max_window_size;
-  *iter_pos = 5 + (quality >> 3);
-  *iter_limit = -quality * iter_mult;
+  *iter_pos = 8 + (quality >> 3);
+  // For lower entropy images, the rigourous search loop in HashChainFindCopy
+  // can be relaxed.
+  *iter_limit = (cache_bits > 0) ? iter_neg : iter_neg / 2;
 }
 
 static int HashChainFindCopy(const HashChain* const p,
-                             int base_position, int xsize,
+                             int base_position, int xsize_signed,
                              const uint32_t* const argb, int maxlen,
                              int window_size, int iter_pos, int iter_limit,
                              int* const distance_ptr,
                              int* const length_ptr) {
-  const uint64_t hash_code = GetPixPairHash64(&argb[base_position]);
-  int prev_length = 0;
-  int64_t best_val = 0;
-  int best_length = 0;
-  int best_distance = 0;
   const uint32_t* const argb_start = argb + base_position;
+  uint64_t best_val = 0;
+  uint32_t best_length = 1;
+  uint32_t best_distance = 0;
+  const uint32_t xsize = (uint32_t)xsize_signed;
   const int min_pos =
       (base_position > window_size) ? base_position - window_size : 0;
   int pos;
-
   assert(xsize > 0);
-  for (pos = p->hash_to_first_index_[hash_code];
+  for (pos = p->hash_to_first_index_[GetPixPairHash64(argb_start)];
        pos >= min_pos;
        pos = p->chain_[pos]) {
-    int64_t val;
-    int curr_length;
+    uint64_t val;
+    uint32_t curr_length;
+    uint32_t distance;
     if (iter_pos < 0) {
       if (iter_pos < iter_limit || best_val >= 0xff0000) {
         break;
       }
     }
     --iter_pos;
-    if (best_length != 0 &&
-        argb[pos + best_length - 1] != argb_start[best_length - 1]) {
+    if (argb[pos + best_length - 1] != argb_start[best_length - 1]) {
       continue;
     }
     curr_length = FindMatchLength(argb + pos, argb_start, maxlen);
-    if (curr_length < prev_length) {
+    if (curr_length < best_length) {
       continue;
     }
-    val = 65536 * curr_length;
+    distance = (uint32_t)(base_position - pos);
+    val = curr_length << 16;
     // Favoring 2d locality here gives savings for certain images.
-    if (base_position - pos < 9 * xsize) {
-      const int y = (base_position - pos) / xsize;
-      int x = (base_position - pos) % xsize;
-      if (x > xsize / 2) {
+    if (distance < 9 * xsize) {
+      const uint32_t y = distance / xsize;
+      uint32_t x = distance % xsize;
+      if (x > (xsize >> 1)) {
         x = xsize - x;
       }
-      if (x <= 7 && x >= -8) {
+      if (x <= 7) {
+        val += 9 * 9 + 9 * 9;
         val -= y * y + x * x;
-      } else {
-        val -= 9 * 9 + 9 * 9;
       }
-    } else {
-      val -= 9 * 9 + 9 * 9;
     }
     if (best_val < val) {
-      prev_length = curr_length;
       best_val = val;
       best_length = curr_length;
-      best_distance = base_position - pos;
+      best_distance = distance;
       if (curr_length >= MAX_LENGTH) {
         break;
       }
-      if ((best_distance == 1 || best_distance == xsize) &&
+      if ((best_distance == 1 || distance == xsize) &&
           best_length >= 128) {
         break;
       }
     }
   }
-  *distance_ptr = best_distance;
+  *distance_ptr = (int)best_distance;
   *length_ptr = best_length;
   return (best_length >= MIN_LENGTH);
 }
@@ -284,8 +284,8 @@ static int BackwardReferencesHashChain(int xsize, int ysize,
   if (!HashChainInit(hash_chain, pix_count)) goto Error;
 
   refs->size = 0;
-  GetParamsForHashChainFindCopy(quality, xsize, &window_size, &iter_pos,
-                                &iter_limit);
+  GetParamsForHashChainFindCopy(quality, xsize, cache_bits,
+                                &window_size, &iter_pos, &iter_limit);
   for (i = 0; i < pix_count; ) {
     // Alternative#1: Code the pixels starting at 'i' using backward reference.
     int offset = 0;
@@ -510,8 +510,8 @@ static int BackwardReferencesHashChainDistanceOnly(
   // We loop one pixel at a time, but store all currently best points to
   // non-processed locations from this point.
   dist_array[0] = 0;
-  GetParamsForHashChainFindCopy(quality, xsize, &window_size, &iter_pos,
-                                &iter_limit);
+  GetParamsForHashChainFindCopy(quality, xsize, cache_bits,
+                                &window_size, &iter_pos, &iter_limit);
   for (i = 0; i < pix_count; ++i) {
     double prev_cost = 0.0;
     int shortmax;
@@ -645,8 +645,8 @@ static int BackwardReferencesHashChainFollowChosenPath(
   }
 
   refs->size = 0;
-  GetParamsForHashChainFindCopy(quality, xsize, &window_size, &iter_pos,
-                                &iter_limit);
+  GetParamsForHashChainFindCopy(quality, xsize, cache_bits,
+                                &window_size, &iter_pos, &iter_limit);
   for (ix = 0; ix < chosen_path_size; ++ix, ++size) {
     int offset = 0;
     int len = 0;
@@ -785,7 +785,9 @@ int VP8LGetBackwardReferences(int width, int height,
     *best = refs_lz77;   // default guess: lz77 is better
     VP8LClearBackwardRefs(&refs_rle);
     if (try_lz77_trace_backwards) {
-      const int recursion_level = (num_pix < 320 * 200) ? 1 : 0;
+      // Set recursion level for large images using a color cache.
+      const int recursion_level =
+          (num_pix < 320 * 200) && (cache_bits > 0) ? 1 : 0;
       VP8LBackwardRefs refs_trace;
       if (!VP8LBackwardRefsAlloc(&refs_trace, num_pix)) {
         goto End;
diff --git a/third_party/libwebp/enc/backward_references.h b/third_party/libwebp/enc/backward_references.h
index 8cb1a7a..b0d1813 100644
--- a/third_party/libwebp/enc/backward_references.h
+++ b/third_party/libwebp/enc/backward_references.h
@@ -1,8 +1,10 @@
 // Copyright 2012 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Author: Jyrki Alakuijala (jyrki@google.com)
diff --git a/third_party/libwebp/enc/config.c b/third_party/libwebp/enc/config.c
index bb88111..acf96b0 100644
--- a/third_party/libwebp/enc/config.c
+++ b/third_party/libwebp/enc/config.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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
diff --git a/third_party/libwebp/enc/cost.c b/third_party/libwebp/enc/cost.c
index 89b60ba..d4916d7 100644
--- a/third_party/libwebp/enc/cost.c
+++ b/third_party/libwebp/enc/cost.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Cost tables for level and modes
diff --git a/third_party/libwebp/enc/cost.h b/third_party/libwebp/enc/cost.h
index e264d32..7d7c2c7 100644
--- a/third_party/libwebp/enc/cost.h
+++ b/third_party/libwebp/enc/cost.h
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Cost tables for level and modes.
diff --git a/third_party/libwebp/enc/filter.c b/third_party/libwebp/enc/filter.c
index 7fb78a3..aae2723d 100644
--- a/third_party/libwebp/enc/filter.c
+++ b/third_party/libwebp/enc/filter.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Selecting filter level
diff --git a/third_party/libwebp/enc/frame.c b/third_party/libwebp/enc/frame.c
index 9520618..c56abed 100644
--- a/third_party/libwebp/enc/frame.c
+++ b/third_party/libwebp/enc/frame.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 //   frame coding and analysis
diff --git a/third_party/libwebp/enc/histogram.c b/third_party/libwebp/enc/histogram.c
index 69e5fa3..787ea5d 100644
--- a/third_party/libwebp/enc/histogram.c
+++ b/third_party/libwebp/enc/histogram.c
@@ -1,8 +1,10 @@
 // Copyright 2012 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Author: Jyrki Alakuijala (jyrki@google.com)
diff --git a/third_party/libwebp/enc/histogram.h b/third_party/libwebp/enc/histogram.h
index fe7cea6..583b5a4 100644
--- a/third_party/libwebp/enc/histogram.h
+++ b/third_party/libwebp/enc/histogram.h
@@ -1,8 +1,10 @@
 // Copyright 2012 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Author: Jyrki Alakuijala (jyrki@google.com)
diff --git a/third_party/libwebp/enc/iterator.c b/third_party/libwebp/enc/iterator.c
index 86e473b..0746659 100644
--- a/third_party/libwebp/enc/iterator.c
+++ b/third_party/libwebp/enc/iterator.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // VP8Iterator: block iterator
diff --git a/third_party/libwebp/enc/layer.c b/third_party/libwebp/enc/layer.c
index 423127d..fa89660 100644
--- a/third_party/libwebp/enc/layer.c
+++ b/third_party/libwebp/enc/layer.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Enhancement layer (for YUV444/422)
diff --git a/third_party/libwebp/enc/picture.c b/third_party/libwebp/enc/picture.c
index 1e51a8d..5aaa385 100644
--- a/third_party/libwebp/enc/picture.c
+++ b/third_party/libwebp/enc/picture.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // WebPPicture utils: colorspace conversion, crop, ...
@@ -709,7 +711,7 @@ static int Import(WebPPicture* const picture,
     for (y = 0; y < height; ++y) {
       for (x = 0; x < width; ++x) {
         const int offset = step * x + y * rgb_stride;
-        const uint32_t argb = (a_ptr[offset] << 24) |
+        const uint32_t argb = ((uint32_t)a_ptr[offset] << 24) |
                               (r_ptr[offset] << 16) |
                               (g_ptr[offset] <<  8) |
                               (b_ptr[offset]);
@@ -809,7 +811,7 @@ int WebPPictureYUVAToARGB(WebPPicture* picture) {
         const uint8_t* const src = picture->a + y * picture->a_stride;
         int x;
         for (x = 0; x < width; ++x) {
-          argb_dst[x] = (argb_dst[x] & 0x00ffffffu) | (src[x] << 24);
+          argb_dst[x] = (argb_dst[x] & 0x00ffffffu) | ((uint32_t)src[x] << 24);
         }
       }
     }
diff --git a/third_party/libwebp/enc/quant.c b/third_party/libwebp/enc/quant.c
index dcfd4d16..462d4e9 100644
--- a/third_party/libwebp/enc/quant.c
+++ b/third_party/libwebp/enc/quant.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 //   Quantization
diff --git a/third_party/libwebp/enc/syntax.c b/third_party/libwebp/enc/syntax.c
index e81fa2b..b0f7676 100644
--- a/third_party/libwebp/enc/syntax.c
+++ b/third_party/libwebp/enc/syntax.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Header syntax writing
diff --git a/third_party/libwebp/enc/token.c b/third_party/libwebp/enc/token.c
index 4e2f6c0..6a63371 100644
--- a/third_party/libwebp/enc/token.c
+++ b/third_party/libwebp/enc/token.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Paginated token buffer
diff --git a/third_party/libwebp/enc/tree.c b/third_party/libwebp/enc/tree.c
index 8b25e5e..ecd8fb9 100644
--- a/third_party/libwebp/enc/tree.c
+++ b/third_party/libwebp/enc/tree.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Token probabilities
diff --git a/third_party/libwebp/enc/vp8enci.h b/third_party/libwebp/enc/vp8enci.h
index 6aa3f43..61d56be 100644
--- a/third_party/libwebp/enc/vp8enci.h
+++ b/third_party/libwebp/enc/vp8enci.h
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 //   WebP encoder: internal header.
@@ -28,7 +30,7 @@ extern "C" {
 // version numbers
 #define ENC_MAJ_VERSION 0
 #define ENC_MIN_VERSION 3
-#define ENC_REV_VERSION 0
+#define ENC_REV_VERSION 1
 
 // intra prediction modes
 enum { B_DC_PRED = 0,   // 4x4 modes
diff --git a/third_party/libwebp/enc/vp8l.c b/third_party/libwebp/enc/vp8l.c
index 5077167..945870c 100644
--- a/third_party/libwebp/enc/vp8l.c
+++ b/third_party/libwebp/enc/vp8l.c
@@ -1,8 +1,10 @@
 // Copyright 2012 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // main entry for the lossless encoder.
@@ -86,7 +88,7 @@ static int AnalyzeAndCreatePalette(const WebPPicture* const pic,
     argb += pic->argb_stride;
   }
 
-  // TODO(skal): could we reuse in_use[] to speed up ApplyPalette()?
+  // TODO(skal): could we reuse in_use[] to speed up EncodePalette()?
   num_colors = 0;
   for (i = 0; i < (int)(sizeof(in_use) / sizeof(in_use[0])); ++i) {
     if (in_use[i]) {
@@ -811,34 +813,66 @@ static WebPEncodingError AllocateTransformBuffer(VP8LEncoder* const enc,
   return err;
 }
 
-// Bundles multiple (1, 2, 4 or 8) pixels into a single pixel.
-static void BundleColorMap(const uint8_t* const row, int width,
-                           int xbits, uint32_t* const dst) {
-  int x;
-  if (xbits > 0) {
-    const int bit_depth = 1 << (3 - xbits);
-    const int mask = (1 << xbits) - 1;
-    uint32_t code = 0xff000000;
-    for (x = 0; x < width; ++x) {
-      const int xsub = x & mask;
-      if (xsub == 0) {
-        code = 0xff000000;
+static void ApplyPalette(uint32_t* src, uint32_t* dst,
+                         uint32_t src_stride, uint32_t dst_stride,
+                         const uint32_t* palette, int palette_size,
+                         int width, int height, int xbits, uint8_t* row) {
+  int i, x, y;
+  int use_LUT = 1;
+  for (i = 0; i < palette_size; ++i) {
+    if ((palette[i] & 0xffff00ffu) != 0) {
+      use_LUT = 0;
+      break;
+    }
+  }
+
+  if (use_LUT) {
+    int inv_palette[MAX_PALETTE_SIZE] = { 0 };
+    for (i = 0; i < palette_size; ++i) {
+      const int color = (palette[i] >> 8) & 0xff;
+      inv_palette[color] = i;
+    }
+    for (y = 0; y < height; ++y) {
+      for (x = 0; x < width; ++x) {
+        const int color = (src[x] >> 8) & 0xff;
+        row[x] = inv_palette[color];
       }
-      code |= row[x] << (8 + bit_depth * xsub);
-      dst[x >> xbits] = code;
+      VP8LBundleColorMap(row, width, xbits, dst);
+      src += src_stride;
+      dst += dst_stride;
     }
   } else {
-    for (x = 0; x < width; ++x) dst[x] = 0xff000000 | (row[x] << 8);
+    // Use 1 pixel cache for ARGB pixels.
+    uint32_t last_pix = palette[0];
+    int last_idx = 0;
+    for (y = 0; y < height; ++y) {
+      for (x = 0; x < width; ++x) {
+        const uint32_t pix = src[x];
+        if (pix != last_pix) {
+          for (i = 0; i < palette_size; ++i) {
+            if (pix == palette[i]) {
+              last_idx = i;
+              last_pix = pix;
+              break;
+            }
+          }
+        }
+        row[x] = last_idx;
+      }
+      VP8LBundleColorMap(row, width, xbits, dst);
+      src += src_stride;
+      dst += dst_stride;
+    }
   }
 }
 
 // Note: Expects "enc->palette_" to be set properly.
 // Also, "enc->palette_" will be modified after this call and should not be used
 // later.
-static WebPEncodingError ApplyPalette(VP8LBitWriter* const bw,
-                                      VP8LEncoder* const enc, int quality) {
+static WebPEncodingError EncodePalette(VP8LBitWriter* const bw,
+                                       VP8LEncoder* const enc, int quality) {
   WebPEncodingError err = VP8_ENC_OK;
-  int i, x, y;
+  int i;
   const WebPPicture* const pic = enc->pic_;
   uint32_t* src = pic->argb;
   uint32_t* dst;
@@ -864,20 +898,8 @@ static WebPEncodingError ApplyPalette(VP8LBitWriter* const bw,
   row = WebPSafeMalloc((uint64_t)width, sizeof(*row));
   if (row == NULL) return VP8_ENC_ERROR_OUT_OF_MEMORY;
 
-  for (y = 0; y < height; ++y) {
-    for (x = 0; x < width; ++x) {
-      const uint32_t pix = src[x];
-      for (i = 0; i < palette_size; ++i) {
-        if (pix == palette[i]) {
-          row[x] = i;
-          break;
-        }
-      }
-    }
-    BundleColorMap(row, width, xbits, dst);
-    src += pic->argb_stride;
-    dst += enc->current_width_;
-  }
+  ApplyPalette(src, dst, pic->argb_stride, enc->current_width_,
+               palette, palette_size, width, height, xbits, row);
 
   // Save palette to bitstream.
   VP8LWriteBits(bw, 1, TRANSFORM_PRESENT);
@@ -899,13 +921,10 @@ static WebPEncodingError ApplyPalette(VP8LBitWriter* const bw,
 
 // -----------------------------------------------------------------------------
 
-static int GetHistoBits(const WebPConfig* const config,
-                        const WebPPicture* const pic) {
-  const int width = pic->width;
-  const int height = pic->height;
+static int GetHistoBits(int method, int use_palette, int width, int height) {
   const uint64_t hist_size = sizeof(VP8LHistogram);
   // Make tile size a function of encoding method (Range: 0 to 6).
-  int histo_bits = 7 - config->method;
+  int histo_bits = (use_palette ? 9 : 7) - method;
   while (1) {
     const uint64_t huff_image_size = VP8LSubSampleSize(width, histo_bits) *
                                      VP8LSubSampleSize(height, histo_bits) *
@@ -917,13 +936,14 @@ static int GetHistoBits(const WebPConfig* const config,
          (histo_bits > MAX_HUFFMAN_BITS) ? MAX_HUFFMAN_BITS : histo_bits;
 }
 
-static void InitEncParams(VP8LEncoder* const enc) {
+static void FinishEncParams(VP8LEncoder* const enc) {
   const WebPConfig* const config = enc->config_;
-  const WebPPicture* const picture = enc->pic_;
+  const WebPPicture* const pic = enc->pic_;
   const int method = config->method;
   const float quality = config->quality;
+  const int use_palette = enc->use_palette_;
   enc->transform_bits_ = (method < 4) ? 5 : (method > 4) ? 3 : 4;
-  enc->histo_bits_ = GetHistoBits(config, picture);
+  enc->histo_bits_ = GetHistoBits(method, use_palette, pic->width, pic->height);
   enc->cache_bits_ = (quality <= 25.f) ? 0 : 7;
 }
 
@@ -965,8 +985,6 @@ WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
     goto Error;
   }
 
-  InitEncParams(enc);
-
   // ---------------------------------------------------------------------------
   // Analyze image (entropy, num_palettes etc)
 
@@ -975,8 +993,10 @@ WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
     goto Error;
   }
 
+  FinishEncParams(enc);
+
   if (enc->use_palette_) {
-    err = ApplyPalette(bw, enc, quality);
+    err = EncodePalette(bw, enc, quality);
     if (err != VP8_ENC_OK) goto Error;
     // Color cache is disabled for palette.
     enc->cache_bits_ = 0;
diff --git a/third_party/libwebp/enc/vp8li.h b/third_party/libwebp/enc/vp8li.h
index eae90dd..01f01f5 100644
--- a/third_party/libwebp/enc/vp8li.h
+++ b/third_party/libwebp/enc/vp8li.h
@@ -1,8 +1,10 @@
 // Copyright 2012 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // Lossless encoder: internal header.
diff --git a/third_party/libwebp/enc/webpenc.c b/third_party/libwebp/enc/webpenc.c
index 20fbac4..d420d06 100644
--- a/third_party/libwebp/enc/webpenc.c
+++ b/third_party/libwebp/enc/webpenc.c
@@ -1,8 +1,10 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 //
-// This code is licensed under the same terms as WebM:
-//  Software License Agreement:  http://www.webmproject.org/license/software/
-//  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
+// 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.
 // -----------------------------------------------------------------------------
 //
 // WebP encoder: main entry point
@@ -386,9 +388,9 @@ int WebPEncode(const WebPConfig* config, WebPPicture* pic) {
     // Analysis is done, proceed to actual coding.
     ok = ok && VP8EncStartAlpha(enc);   // possibly done in parallel
     if (!enc->use_tokens_) {
-      ok = VP8EncLoop(enc);
+      ok = ok && VP8EncLoop(enc);
     } else {
-      ok = VP8EncTokenLoop(enc);
+      ok = ok && VP8EncTokenLoop(enc);
     }
     ok = ok && VP8EncFinishAlpha(enc);
 #ifdef WEBP_EXPERIMENTAL_FEATURES