Add HE AAC support to ISO BMFF.

content/common/gpu/media/h264_parser.h

 // Copyright (c) 2012 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.
 //
 // This file contains an implementation of an H264 Annex-B video stream parser.
 
 #ifndef CONTENT_COMMON_GPU_MEDIA_H264_PARSER_H_
 #define CONTENT_COMMON_GPU_MEDIA_H264_PARSER_H_
 
 #include <sys/types.h>
 
 #include <map>
 
 #include "base/basictypes.h"
+#include "base/compiler_specific.h"
 #include "content/common/content_export.h"
+#include "media/base/bit_reader.h"
 
 namespace content {
 
 // For explanations of each struct and its members, see H.264 specification
 // at http://www.itu.int/rec/T-REC-H.264.
 struct CONTENT_EXPORT H264NALU {
   H264NALU();
 
   enum Type {
     kUnspecified = 0,
@@ skipping 269 matching lines @@
   // Parse a slice header, returning it in |*shdr|. |*nalu| must be set to
   // the NALU returned from AdvanceToNextNALU() and corresponding to |*shdr|.
   Result ParseSliceHeader(const H264NALU& nalu, H264SliceHeader* shdr);
 
   // Parse a SEI message, returning it in |*sei_msg|, provided and managed
   // by the caller.
   Result ParseSEI(H264SEIMessage* sei_msg);
 
  private:
   // A class to provide bit-granularity reading of H.264 streams.
-  // This is not a generic bit reader class, as it takes into account
-  // H.264 stream-specific constraints, such as skipping emulation-prevention
-  // bytes and stop bits. See spec for more details.
+  // This class takes into account H.264 stream-specific constraints, such as
+  // skipping emulation-prevention bytes and stop bits. See spec for more
+  // details.
   // TODO(posciak): need separate unittests for this class.
-  class H264BitReader {
+  class H264BitReader : public media::BitReader {
    public:
     H264BitReader();
-    ~H264BitReader();
-
-    // Initialize the reader to start reading at |data|, |size| being size
-    // of |data| in bytes.
-    // Return false on insufficient size of stream..
-    // TODO(posciak,fischman): consider replacing Initialize() with
-    // heap-allocating and creating bit readers on demand instead.
-    bool Initialize(const uint8* data, off_t size);
-
-    // Read |num_bits| next bits from stream and return in |*out|, first bit
-    // from the stream starting at |num_bits| position in |*out|.
-    // |num_bits| may be 1-32, inclusive.
-    // Return false if the given number of bits cannot be read (not enough
-    // bits in the stream), true otherwise.
-    bool ReadBits(int num_bits, int *out);
-
-    // Return the number of bits left in the stream.
-    off_t NumBitsLeft();
-
-    // See the definition of more_rbsp_data() in spec.
-    bool HasMoreRBSPData();
+    virtual ~H264BitReader() OVERRIDE;
 
    private:
-    // Advance to the next byte, loading it into curr_byte_.
-    // Return false on end of stream.
-    bool UpdateCurrByte();
-
-    // Pointer to the next unread (not in curr_byte_) byte in the stream.
-    const uint8* data_;
-
-    // Bytes left in the stream (without the curr_byte_).
-    off_t bytes_left_;
-
-    // Contents of the current byte; first unread bit starting at position
-    // 8 - num_remaining_bits_in_curr_byte_ from MSB.
-    int curr_byte_;
-
-    // Number of bits remaining in curr_byte_
-    int num_remaining_bits_in_curr_byte_;
-
-    // Used in emulation prevention three byte detection (see spec).
-    // Initially set to 0xffff to accept all initial two-byte sequences.
-    int prev_two_bytes_;
-
-    DISALLOW_COPY_AND_ASSIGN(H264BitReader);

[acolwell GONE FROM CHROMIUM, 2012/06/28 17:31:25]

nit: You should keep the DISALLOW_COPY_AND_ASSIGN()

+    // This function handles the H.264 escape sequence and stop bit.
+    virtual void UpdateCurrByte() OVERRIDE;
   };
 
   // Exp-Golomb code parsing as specified in chapter 9.1 of the spec.
   // Read one unsigned exp-Golomb code from the stream and return in |*val|.
   Result ReadUE(int* val);
 
   // Read one signed exp-Golomb code from the stream and return in |*val|.
   Result ReadSE(int* val);
 
   // Parse scaling lists (see spec).
@@ skipping 32 matching lines @@
   typedef std::map<int, H264PPS*> PPSById;
   SPSById active_SPSes_;
   PPSById active_PPSes_;
 
   DISALLOW_COPY_AND_ASSIGN(H264Parser);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_GPU_MEDIA_H264_PARSER_H_