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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_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, but no audio or video buffers have
     80   // been parsed yet.
     81   bool waiting_for_buffers_;
     82 
     83   scoped_ptr<WebMClusterParser> cluster_parser_;
     84   ByteQueue byte_queue_;
     85 
     86   DISALLOW_COPY_AND_ASSIGN(WebMStreamParser);
     87 };
     88 
     89 }  // namespace media
     90 
     91 #endif  // MEDIA_WEBM_WEBM_STREAM_PARSER_H_
     92