media/formats/mp4/mp4_stream_parser.h

   1 // Copyright 2014 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_FORMATS_MP4_MP4_STREAM_PARSER_H_
   6 #define MEDIA_FORMATS_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/formats/common/offset_byte_queue.h"
  18 #include "media/formats/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                     bool ignore_text_tracks,
  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     kWaitingForSampleData,
  46     kEmittingSamples,
  47     kError
  48   };
  49
  50   bool ParseBox(bool* err);
  51   bool ParseMoov(mp4::BoxReader* reader);
  52   bool ParseMoof(mp4::BoxReader* reader);
  53
  54   void EmitNeedKeyIfNecessary(
  55       const std::vector<ProtectionSystemSpecificHeader>& headers);
  56
  57   // To retain proper framing, each 'mdat' atom must be read; to limit memory
  58   // usage, the atom's data needs to be discarded incrementally as frames are
  59   // extracted from the stream. This function discards data from the stream up
  60   // to |max_clear_offset|, updating the |mdat_tail_| value so that framing can
  61   // be retained after all 'mdat' information has been read. |max_clear_offset|
  62   // is the upper bound on what can be removed from |queue_|. Anything below
  63   // this offset is no longer needed by the parser.
  64   // Returns 'true' on success, 'false' if there was an error.
  65   bool ReadAndDiscardMDATsUntil(int64 max_clear_offset);
  66
  67   void ChangeState(State new_state);
  68
  69   bool EmitConfigs();
  70   bool PrepareAVCBuffer(const AVCDecoderConfigurationRecord& avc_config,
  71                         std::vector<uint8>* frame_buf,
  72                         std::vector<SubsampleEntry>* subsamples) const;
  73   bool PrepareAACBuffer(const AAC& aac_config,
  74                         std::vector<uint8>* frame_buf,
  75                         std::vector<SubsampleEntry>* subsamples) const;
  76   bool EnqueueSample(BufferQueue* audio_buffers,
  77                      BufferQueue* video_buffers,
  78                      bool* err);
  79   bool SendAndFlushSamples(BufferQueue* audio_buffers,
  80                            BufferQueue* video_buffers);
  81
  82   void Reset();
  83
  84   // Checks to see if we have enough data in |queue_| to transition to
  85   // kEmittingSamples and start enqueuing samples.
  86   bool HaveEnoughDataToEnqueueSamples();
  87
  88   // Sets |highest_end_offset_| based on the data in |moov_|
  89   // and |moof|. Returns true if |highest_end_offset_| was successfully
  90   // computed.
  91   bool ComputeHighestEndOffset(const MovieFragment& moof);
  92
  93   State state_;
  94   InitCB init_cb_;
  95   NewConfigCB config_cb_;
  96   NewBuffersCB new_buffers_cb_;
  97   NeedKeyCB need_key_cb_;
  98   NewMediaSegmentCB new_segment_cb_;
  99   base::Closure end_of_segment_cb_;
 100   LogCB log_cb_;
 101
 102   OffsetByteQueue queue_;
 103
 104   // These two parameters are only valid in the |kEmittingSegments| state.
 105   //
 106   // |moof_head_| is the offset of the start of the most recently parsed moof
 107   // block. All byte offsets in sample information are relative to this offset,
 108   // as mandated by the Media Source spec.
 109   int64 moof_head_;
 110   // |mdat_tail_| is the stream offset of the end of the current 'mdat' box.
 111   // Valid iff it is greater than the head of the queue.
 112   int64 mdat_tail_;
 113
 114   // The highest end offset in the current moof. This offset is
 115   // relative to |moof_head_|. This value is used to make sure we have collected
 116   // enough bytes to parse all samples and aux_info in the current moof.
 117   int64 highest_end_offset_;
 118
 119   scoped_ptr<mp4::Movie> moov_;
 120   scoped_ptr<mp4::TrackRunIterator> runs_;
 121
 122   bool has_audio_;
 123   bool has_video_;
 124   uint32 audio_track_id_;
 125   uint32 video_track_id_;
 126   // The object types allowed for audio tracks.
 127   std::set<int> audio_object_types_;
 128   bool has_sbr_;
 129   bool is_audio_track_encrypted_;
 130   bool is_video_track_encrypted_;
 131
 132   DISALLOW_COPY_AND_ASSIGN(MP4StreamParser);
 133 };
 134
 135 }  // namespace mp4
 136 }  // namespace media
 137
 138 #endif  // MEDIA_FORMATS_MP4_MP4_STREAM_PARSER_H_