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