libwebp: update to 0.4.1

third_party/libwebp/dec/tree.c

Index: third_party/libwebp/dec/tree.c
diff --git a/third_party/libwebp/dec/tree.c b/third_party/libwebp/dec/tree.c
index bf9b7c551a13cf17a7f5ba2a35c2ea296eb93519..88238885d32551a327b5335791beb434c01e67f7 100644
--- a/third_party/libwebp/dec/tree.c
+++ b/third_party/libwebp/dec/tree.c
@@ -12,6 +12,7 @@
 // Author: Skal (pascal.massimino@gmail.com)
 
 #include "vp8i.h"
+#include "../utils/bit_reader_inl.h"
 
 #define USE_GENERIC_TREE
 
@@ -278,10 +279,23 @@ void VP8ResetProba(VP8Proba* const proba) {
   // proba->bands_[][] is initialized later
 }
 
-void VP8ParseIntraMode(VP8BitReader* const br, VP8Decoder* const dec) {
-  uint8_t* const top = dec->intra_t_ + 4 * dec->mb_x_;
+static void ParseIntraMode(VP8BitReader* const br,
+                           VP8Decoder* const dec, int mb_x) {
+  uint8_t* const top = dec->intra_t_ + 4 * mb_x;
   uint8_t* const left = dec->intra_l_;
-  VP8MBData* const block = dec->mb_data_ + dec->mb_x_;
+  VP8MBData* const block = dec->mb_data_ + mb_x;
+
+  // Note: we don't save segment map (yet), as we don't expect
+  // to decode more than 1 keyframe.
+  if (dec->segment_hdr_.update_map_) {
+    // Hardcoded tree parsing
+    block->segment_ = !VP8GetBit(br, dec->proba_.segments_[0])
+                    ? VP8GetBit(br, dec->proba_.segments_[1])
+                    : 2 + VP8GetBit(br, dec->proba_.segments_[2]);
+  } else {
+    block->segment_ = 0;  // default for intra
+  }
+  if (dec->use_skip_proba_) block->skip_ = VP8GetBit(br, dec->skip_p_);
 
   block->is_i4x4_ = !VP8GetBit(br, 145);   // decide for B_PRED first
   if (!block->is_i4x4_) {
@@ -332,6 +346,14 @@ void VP8ParseIntraMode(VP8BitReader* const br, VP8Decoder* const dec) {
                  : VP8GetBit(br, 183) ? TM_PRED : H_PRED;
 }
 
+int VP8ParseIntraModeRow(VP8BitReader* const br, VP8Decoder* const dec) {
+  int mb_x;
+  for (mb_x = 0; mb_x < dec->mb_w_; ++mb_x) {
+    ParseIntraMode(br, dec, mb_x);
+  }
+  return !dec->br_.eof_;
+}
+
 //------------------------------------------------------------------------------
 // Paragraph 13