media/webm/webm_stream_parser.h

   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_WEBM_WEBM_STREAM_PARSER_H_
   6 #define MEDIA_WEBM_WEBM_STREAM_PARSER_H_
   7
   8 #include <map>
   9
  10 #include "base/callback_forward.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "media/base/audio_decoder_config.h"
  13 #include "media/base/buffers.h"
  14 #include "media/base/byte_queue.h"
  15 #include "media/base/stream_parser.h"
  16 #include "media/base/video_decoder_config.h"
  17
  18 namespace media {
  19
  20 class WebMClusterParser;
  21
  22 class WebMStreamParser : public StreamParser {
  23  public:
  24   WebMStreamParser();
  25   virtual ~WebMStreamParser();
  26
  27   // StreamParser implementation.
  28   virtual void Init(const InitCB& init_cb, const NewConfigCB& config_cb,
  29                     const NewBuffersCB& new_buffers_cb,
  30                     const NewTextBuffersCB& text_cb,
  31                     const NeedKeyCB& need_key_cb,
  32                     const AddTextTrackCB& add_text_track_cb,
  33                     const NewMediaSegmentCB& new_segment_cb,
  34                     const base::Closure& end_of_segment_cb,
  35                     const LogCB& log_cb) OVERRIDE;
  36   virtual void Flush() OVERRIDE;
  37   virtual bool Parse(const uint8* buf, int size) OVERRIDE;
  38
  39  private:
  40   enum State {
  41     kWaitingForInit,
  42     kParsingHeaders,
  43     kParsingClusters,
  44     kError
  45   };
  46
  47   void ChangeState(State new_state);
  48
  49   // Parses WebM Header, Info, Tracks elements. It also skips other level 1
  50   // elements that are not used right now. Once the Info & Tracks elements have
  51   // been parsed, this method will transition the parser from PARSING_HEADERS to
  52   // PARSING_CLUSTERS.
  53   //
  54   // Returns < 0 if the parse fails.
  55   // Returns 0 if more data is needed.
  56   // Returning > 0 indicates success & the number of bytes parsed.
  57   int ParseInfoAndTracks(const uint8* data, int size);
  58
  59   // Incrementally parses WebM cluster elements. This method also skips
  60   // CUES elements if they are encountered since we currently don't use the
  61   // data in these elements.
  62   //
  63   // Returns < 0 if the parse fails.
  64   // Returns 0 if more data is needed.
  65   // Returning > 0 indicates success & the number of bytes parsed.
  66   int ParseCluster(const uint8* data, int size);
  67
  68   // Fire needkey event through the |need_key_cb_|.
  69   void FireNeedKey(const std::string& key_id);
  70
  71   State state_;
  72   InitCB init_cb_;
  73   NewConfigCB config_cb_;
  74   NewBuffersCB new_buffers_cb_;
  75   NewTextBuffersCB text_cb_;
  76   NeedKeyCB need_key_cb_;
  77   AddTextTrackCB add_text_track_cb_;
  78
  79   typedef std::map<int, TextTrack* > TextTrackMap;
  80   TextTrackMap text_track_map_;
  81
  82   NewMediaSegmentCB new_segment_cb_;
  83   base::Closure end_of_segment_cb_;
  84   LogCB log_cb_;
  85
  86   // True if a new cluster id has been seen, but no audio or video buffers have
  87   // been parsed yet.
  88   bool waiting_for_buffers_;
  89
  90   scoped_ptr<WebMClusterParser> cluster_parser_;
  91   ByteQueue byte_queue_;
  92
  93   DISALLOW_COPY_AND_ASSIGN(WebMStreamParser);
  94 };
  95
  96 }  // namespace media
  97
  98 #endif  // MEDIA_WEBM_WEBM_STREAM_PARSER_H_