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
  16 namespace media {
  17
  18 class WebMClusterParser;
  19
  20 class WebMStreamParser : public StreamParser {
  21  public:
  22   WebMStreamParser();
  23   virtual ~WebMStreamParser();
  24
  25   // StreamParser implementation.
  26   virtual void Init(const InitCB& init_cb, const NewConfigCB& config_cb,
  27                     const NewBuffersCB& new_buffers_cb,
  28                     const NewTextBuffersCB& text_cb,
  29                     const NeedKeyCB& need_key_cb,
  30                     const NewMediaSegmentCB& new_segment_cb,
  31                     const base::Closure& end_of_segment_cb,
  32                     const LogCB& log_cb) OVERRIDE;
  33   virtual void Flush() OVERRIDE;
  34   virtual bool Parse(const uint8* buf, int size) OVERRIDE;
  35
  36  private:
  37   enum State {
  38     kWaitingForInit,
  39     kParsingHeaders,
  40     kParsingClusters,
  41     kError
  42   };
  43
  44   void ChangeState(State new_state);
  45
  46   // Parses WebM Header, Info, Tracks elements. It also skips other level 1
  47   // elements that are not used right now. Once the Info & Tracks elements have
  48   // been parsed, this method will transition the parser from PARSING_HEADERS to
  49   // PARSING_CLUSTERS.
  50   //
  51   // Returns < 0 if the parse fails.
  52   // Returns 0 if more data is needed.
  53   // Returning > 0 indicates success & the number of bytes parsed.
  54   int ParseInfoAndTracks(const uint8* data, int size);
  55
  56   // Incrementally parses WebM cluster elements. This method also skips
  57   // CUES elements if they are encountered since we currently don't use the
  58   // data in these elements.
  59   //
  60   // Returns < 0 if the parse fails.
  61   // Returns 0 if more data is needed.
  62   // Returning > 0 indicates success & the number of bytes parsed.
  63   int ParseCluster(const uint8* data, int size);
  64
  65   // Fire needkey event through the |need_key_cb_|.
  66   void FireNeedKey(const std::string& key_id);
  67
  68   State state_;
  69   InitCB init_cb_;
  70   NewConfigCB config_cb_;
  71   NewBuffersCB new_buffers_cb_;
  72   NewTextBuffersCB text_cb_;
  73   NeedKeyCB need_key_cb_;
  74
  75   NewMediaSegmentCB new_segment_cb_;
  76   base::Closure end_of_segment_cb_;
  77   LogCB log_cb_;
  78
  79   // True if a new cluster id has been seen and its end has not yet been parsed.
  80   bool parsing_cluster_;
  81
  82   scoped_ptr<WebMClusterParser> cluster_parser_;
  83   ByteQueue byte_queue_;
  84
  85   DISALLOW_COPY_AND_ASSIGN(WebMStreamParser);
  86 };
  87
  88 }  // namespace media
  89
  90 #endif  // MEDIA_WEBM_WEBM_STREAM_PARSER_H_