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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef MEDIA_MP4_MP4_STREAM_PARSER_H_
      6 #define MEDIA_MP4_MP4_STREAM_PARSER_H_
      7 
      8 #include <set>
      9 #include <vector>
     10 
     11 #include "base/basictypes.h"
     12 #include "base/callback.h"
     13 #include "base/compiler_specific.h"
     14 #include "base/memory/scoped_ptr.h"
     15 #include "media/base/media_export.h"
     16 #include "media/base/stream_parser.h"
     17 #include "media/mp4/offset_byte_queue.h"
     18 #include "media/mp4/track_run_iterator.h"
     19 
     20 namespace media {
     21 namespace mp4 {
     22 
     23 struct Movie;
     24 class BoxReader;
     25 
     26 class MEDIA_EXPORT MP4StreamParser : public StreamParser {
     27  public:
     28   MP4StreamParser(const std::set<int>& audio_object_types, bool has_sbr);
     29   virtual ~MP4StreamParser();
     30 
     31   virtual void Init(const InitCB& init_cb, const NewConfigCB& config_cb,
     32                     const NewBuffersCB& new_buffers_cb,
     33                     const NewTextBuffersCB& text_cb,
     34                     const NeedKeyCB& need_key_cb,
     35                     const NewMediaSegmentCB& new_segment_cb,
     36                     const base::Closure& end_of_segment_cb,
     37                     const LogCB& log_cb) OVERRIDE;
     38   virtual void Flush() OVERRIDE;
     39   virtual bool Parse(const uint8* buf, int size) OVERRIDE;
     40 
     41  private:
     42   enum State {
     43     kWaitingForInit,
     44     kParsingBoxes,
     45     kEmittingSamples,
     46     kError
     47   };
     48 
     49   bool ParseBox(bool* err);
     50   bool ParseMoov(mp4::BoxReader* reader);
     51   bool ParseMoof(mp4::BoxReader* reader);
     52 
     53   void EmitNeedKeyIfNecessary(
     54       const std::vector<ProtectionSystemSpecificHeader>& headers);
     55 
     56   // To retain proper framing, each 'mdat' atom must be read; to limit memory
     57   // usage, the atom's data needs to be discarded incrementally as frames are
     58   // extracted from the stream. This function discards data from the stream up
     59   // to |offset|, updating the |mdat_tail_| value so that framing can be
     60   // retained after all 'mdat' information has been read.
     61   // Returns 'true' on success, 'false' if there was an error.
     62   bool ReadAndDiscardMDATsUntil(const int64 offset);
     63 
     64   void ChangeState(State new_state);
     65 
     66   bool EmitConfigs();
     67   bool PrepareAVCBuffer(const AVCDecoderConfigurationRecord& avc_config,
     68                         std::vector<uint8>* frame_buf,
     69                         std::vector<SubsampleEntry>* subsamples) const;
     70   bool PrepareAACBuffer(const AAC& aac_config,
     71                         std::vector<uint8>* frame_buf,
     72                         std::vector<SubsampleEntry>* subsamples) const;
     73   bool EnqueueSample(BufferQueue* audio_buffers,
     74                      BufferQueue* video_buffers,
     75                      bool* err);
     76   bool SendAndFlushSamples(BufferQueue* audio_buffers,
     77                            BufferQueue* video_buffers);
     78 
     79   void Reset();
     80 
     81   State state_;
     82   InitCB init_cb_;
     83   NewConfigCB config_cb_;
     84   NewBuffersCB new_buffers_cb_;
     85   NeedKeyCB need_key_cb_;
     86   NewMediaSegmentCB new_segment_cb_;
     87   base::Closure end_of_segment_cb_;
     88   LogCB log_cb_;
     89 
     90   OffsetByteQueue queue_;
     91 
     92   // These two parameters are only valid in the |kEmittingSegments| state.
     93   //
     94   // |moof_head_| is the offset of the start of the most recently parsed moof
     95   // block. All byte offsets in sample information are relative to this offset,
     96   // as mandated by the Media Source spec.
     97   int64 moof_head_;
     98   // |mdat_tail_| is the stream offset of the end of the current 'mdat' box.
     99   // Valid iff it is greater than the head of the queue.
    100   int64 mdat_tail_;
    101 
    102   scoped_ptr<mp4::Movie> moov_;
    103   scoped_ptr<mp4::TrackRunIterator> runs_;
    104 
    105   bool has_audio_;
    106   bool has_video_;
    107   uint32 audio_track_id_;
    108   uint32 video_track_id_;
    109   // The object types allowed for audio tracks.
    110   std::set<int> audio_object_types_;
    111   bool has_sbr_;
    112   bool is_audio_track_encrypted_;
    113   bool is_video_track_encrypted_;
    114 
    115   DISALLOW_COPY_AND_ASSIGN(MP4StreamParser);
    116 };
    117 
    118 }  // namespace mp4
    119 }  // namespace media
    120 
    121 #endif  // MEDIA_MP4_MP4_STREAM_PARSER_H_
    122