Parse VP9 compressed header

media/filters/vp9_compressed_header_parser.h

Index: media/filters/vp9_compressed_header_parser.h
diff --git a/media/filters/vp9_compressed_header_parser.h b/media/filters/vp9_compressed_header_parser.h
new file mode 100644
index 0000000000000000000000000000000000000000..7067265ad3f94f552d831ea09f3125c28bc13b8a
--- /dev/null
+++ b/media/filters/vp9_compressed_header_parser.h
@@ -0,0 +1,51 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MEDIA_FILTERS_VP9_COMPRESSED_HEADER_PARSER_H_
+#define MEDIA_FILTERS_VP9_COMPRESSED_HEADER_PARSER_H_
+
+#include "media/filters/vp9_bool_decoder.h"
+#include "media/filters/vp9_parser.h"
+
+namespace media {
+
+class Vp9CompressedHeaderParser {
+ public:
+  Vp9CompressedHeaderParser();
+
+  // Parses VP9 compressed header in |stream| with |frame_size| into |fhdr|.
+  // Returns true if no error.
+  bool Parse(const uint8_t* stream, off_t frame_size, Vp9FrameHeader* fhdr);
+
+ private:
+  void ReadTxMode(Vp9FrameHeader* fhdr);
+  uint8_t DecodeTermSubexp();
+  void DiffUpdateProb(Vp9Prob* prob);
+  template <int N>
+  void DiffUpdateProbArray(Vp9Prob (&prob_array)[N]);
+  void ReadTxModeProbs(Vp9FrameContext* frame_context);
+  void ReadCoefProbs(Vp9FrameHeader* fhdr);
+  void ReadSkipProb(Vp9FrameContext* frame_context);
+  void ReadInterModeProbs(Vp9FrameContext* frame_context);
+  void ReadInterpFilterProbs(Vp9FrameContext* frame_context);
+  void ReadIsInterProbs(Vp9FrameContext* frame_context);
+  void ReadFrameReferenceMode(Vp9FrameHeader* fhdr);
+  void ReadFrameReferenceModeProbs(Vp9FrameHeader* fhdr);
+  void ReadYModeProbs(Vp9FrameContext* frame_context);
+  void ReadPartitionProbs(Vp9FrameContext* frame_context);
+  void ReadMvProbs(bool allow_high_precision_mv,
+                   Vp9FrameContext* frame_context);
+  void UpdateMvProb(Vp9Prob* prob);
+  template <int N>
+  void UpdateMvProbArray(Vp9Prob (&prob_array)[N]);
+
+  // Bool decoder for compressed frame header.
+  Vp9BoolDecoder reader_;
+
+  DISALLOW_COPY_AND_ASSIGN(Vp9CompressedHeaderParser);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_FILTERS_VP9_COMPRESSED_HEADER_PARSER_H_