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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_BASE_STREAM_PARSER_H_
      6 #define MEDIA_BASE_STREAM_PARSER_H_
      7 
      8 #include <deque>
      9 #include <string>
     10 
     11 #include "base/callback_forward.h"
     12 #include "base/memory/ref_counted.h"
     13 #include "base/memory/scoped_ptr.h"
     14 #include "base/time/time.h"
     15 #include "media/base/media_export.h"
     16 #include "media/base/media_log.h"
     17 #include "media/base/text_track.h"
     18 
     19 namespace media {
     20 
     21 class AudioDecoderConfig;
     22 class StreamParserBuffer;
     23 class VideoDecoderConfig;
     24 
     25 // Abstract interface for parsing media byte streams.
     26 class MEDIA_EXPORT StreamParser {
     27  public:
     28   typedef std::deque<scoped_refptr<StreamParserBuffer> > BufferQueue;
     29 
     30   StreamParser();
     31   virtual ~StreamParser();
     32 
     33   // Indicates completion of parser initialization.
     34   // First parameter - Indicates initialization success. Set to true if
     35   //                   initialization was successful. False if an error
     36   //                   occurred.
     37   // Second parameter -  Indicates the stream duration. Only contains a valid
     38   //                     value if the first parameter is true.
     39   typedef base::Callback<void(bool, base::TimeDelta)> InitCB;
     40 
     41   // Indicates when new stream configurations have been parsed.
     42   // First parameter - The new audio configuration. If the config is not valid
     43   //                   then it means that there isn't an audio stream.
     44   // Second parameter - The new video configuration. If the config is not valid
     45   //                    then it means that there isn't an audio stream.
     46   // Return value - True if the new configurations are accepted.
     47   //                False if the new configurations are not supported
     48   //                and indicates that a parsing error should be signalled.
     49   typedef base::Callback<bool(const AudioDecoderConfig&,
     50                               const VideoDecoderConfig&)> NewConfigCB;
     51 
     52   // New stream buffers have been parsed.
     53   // First parameter - A queue of newly parsed audio buffers.
     54   // Second parameter - A queue of newly parsed video buffers.
     55   // Return value - True indicates that the buffers are accepted.
     56   //                False if something was wrong with the buffers and a parsing
     57   //                error should be signalled.
     58   typedef base::Callback<bool(const BufferQueue&,
     59                               const BufferQueue&)> NewBuffersCB;
     60 
     61   // New stream buffers of inband text have been parsed.
     62   // First parameter - The text track to which these cues will be added.
     63   // Second parameter - A queue of newly parsed buffers.
     64   // Return value - True indicates that the buffers are accepted.
     65   //                False if something was wrong with the buffers and a parsing
     66   //                error should be signalled.
     67   typedef base::Callback<bool(TextTrack*, const BufferQueue&)> NewTextBuffersCB;
     68 
     69   // Signals the beginning of a new media segment.
     70   typedef base::Callback<void()> NewMediaSegmentCB;
     71 
     72   // A new potentially encrypted stream has been parsed.
     73   // First parameter - The type of the initialization data associated with the
     74   //                   stream.
     75   // Second parameter - The initialization data associated with the stream.
     76   // Third parameter - Number of bytes of the initialization data.
     77   typedef base::Callback<void(const std::string&,
     78                               scoped_ptr<uint8[]>, int)> NeedKeyCB;
     79 
     80   // Initialize the parser with necessary callbacks. Must be called before any
     81   // data is passed to Parse(). |init_cb| will be called once enough data has
     82   // been parsed to determine the initial stream configurations, presentation
     83   // start time, and duration.
     84   virtual void Init(const InitCB& init_cb,
     85                     const NewConfigCB& config_cb,
     86                     const NewBuffersCB& new_buffers_cb,
     87                     const NewTextBuffersCB& text_cb,
     88                     const NeedKeyCB& need_key_cb,
     89                     const AddTextTrackCB& add_text_track_cb,
     90                     const NewMediaSegmentCB& new_segment_cb,
     91                     const base::Closure& end_of_segment_cb,
     92                     const LogCB& log_cb) = 0;
     93 
     94   // Called when a seek occurs. This flushes the current parser state
     95   // and puts the parser in a state where it can receive data for the new seek
     96   // point.
     97   virtual void Flush() = 0;
     98 
     99   // Called when there is new data to parse.
    100   //
    101   // Returns true if the parse succeeds.
    102   virtual bool Parse(const uint8* buf, int size) = 0;
    103 
    104  private:
    105   DISALLOW_COPY_AND_ASSIGN(StreamParser);
    106 };
    107 
    108 }  // namespace media
    109 
    110 #endif  // MEDIA_BASE_STREAM_PARSER_H_
    111