libwebp: update to 0.5.0

third_party/libwebp/dec/tree.c

 // Copyright 2010 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 trees and probas
@@ skipping 476 matching lines @@
       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
     },
     { { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
       { 254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 },
       { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }
     }
   }
 };
 
 // Paragraph 9.9
+
+static const int kBands[16 + 1] = {
+  0, 1, 2, 3, 6, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7,
+  0  // extra entry as sentinel
+};
+
 void VP8ParseProba(VP8BitReader* const br, VP8Decoder* const dec) {
   VP8Proba* const proba = &dec->proba_;
   int t, b, c, p;
   for (t = 0; t < NUM_TYPES; ++t) {
     for (b = 0; b < NUM_BANDS; ++b) {
       for (c = 0; c < NUM_CTX; ++c) {
         for (p = 0; p < NUM_PROBAS; ++p) {
           const int v = VP8GetBit(br, CoeffsUpdateProba[t][b][c][p]) ?
                         VP8GetValue(br, 8) : CoeffsProba0[t][b][c][p];
           proba->bands_[t][b].probas_[c][p] = v;
         }
       }
     }
+    for (b = 0; b < 16 + 1; ++b) {
+      proba->bands_ptr_[t][b] = &proba->bands_[t][kBands[b]];
+    }
   }
   dec->use_skip_proba_ = VP8Get(br);
   if (dec->use_skip_proba_) {
     dec->skip_p_ = VP8GetValue(br, 8);
   }
 }