media/base/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_BASE_STREAM_PARSER_H_
   6 #define MEDIA_BASE_STREAM_PARSER_H_
   7
   8 #include <deque>
   9 #include <map>
  10 #include <string>
  11 #include <vector>
  12
  13 #include "base/callback_forward.h"
  14 #include "base/memory/ref_counted.h"
  15 #include "base/memory/scoped_ptr.h"
  16 #include "base/time/time.h"
  17 #include "media/base/demuxer_stream.h"
  18 #include "media/base/eme_constants.h"
  19 #include "media/base/media_export.h"
  20 #include "media/base/media_log.h"
  21
  22 namespace media {
  23
  24 class AudioDecoderConfig;
  25 class StreamParserBuffer;
  26 class TextTrackConfig;
  27 class VideoDecoderConfig;
  28
  29 // Abstract interface for parsing media byte streams.
  30 class MEDIA_EXPORT StreamParser {
  31  public:
  32   typedef std::deque<scoped_refptr<StreamParserBuffer> > BufferQueue;
  33
  34   // Range of |TrackId| is dependent upon stream parsers. It is currently
  35   // the key for the buffer's text track config in the applicable
  36   // TextTrackConfigMap (which is passed in StreamParser::NewConfigCB), or
  37   // 0 for other media types that currently allow at most one track.
  38   // WebMTracksParser uses -1 as an invalid text track number.
  39   // TODO(wolenetz/acolwell): Change to size_type while fixing stream parsers to
  40   // emit validated track configuration and buffer vectors rather than max 1
  41   // audio, max 1 video, and N text tracks in a map keyed by
  42   // bytestream-specific-ranged track numbers. See http://crbug.com/341581.
  43   typedef int TrackId;
  44
  45   // Map of text track ID to the track configuration.
  46   typedef std::map<TrackId, TextTrackConfig> TextTrackConfigMap;
  47
  48   // Map of text track ID to decode-timestamp-ordered buffers for the track.
  49   typedef std::map<TrackId, const BufferQueue> TextBufferQueueMap;
  50
  51   // Stream parameters passed in InitCB.
  52   struct InitParameters {
  53     InitParameters(base::TimeDelta duration);
  54
  55     // Stream duration.
  56     base::TimeDelta duration;
  57
  58     // Indicates the source time associated with presentation timestamp 0. A
  59     // null Time is returned if no mapping to Time exists.
  60     base::Time timeline_offset;
  61
  62     // Indicates that timestampOffset should be updated based on the earliest
  63     // end timestamp (audio or video) provided during each NewBuffersCB.
  64     bool auto_update_timestamp_offset;
  65
  66     // Indicates live stream.
  67     DemuxerStream::Liveness liveness;
  68   };
  69
  70   // Indicates completion of parser initialization.
  71   //   params - Stream parameters.
  72   typedef base::Callback<void(const InitParameters& params)> InitCB;
  73
  74   // Indicates when new stream configurations have been parsed.
  75   // First parameter - The new audio configuration. If the config is not valid
  76   //                   then it means that there isn't an audio stream.
  77   // Second parameter - The new video configuration. If the config is not valid
  78   //                    then it means that there isn't an audio stream.
  79   // Third parameter - The new text tracks configuration.  If the map is empty,
  80   //                   then no text tracks were parsed from the stream.
  81   // Return value - True if the new configurations are accepted.
  82   //                False if the new configurations are not supported
  83   //                and indicates that a parsing error should be signalled.
  84   typedef base::Callback<bool(const AudioDecoderConfig&,
  85                               const VideoDecoderConfig&,
  86                               const TextTrackConfigMap&)> NewConfigCB;
  87
  88   // New stream buffers have been parsed.
  89   // First parameter - A queue of newly parsed audio buffers.
  90   // Second parameter - A queue of newly parsed video buffers.
  91   // Third parameter - A map of text track ids to queues of newly parsed inband
  92   //                   text buffers. If the map is not empty, it must contain
  93   //                   at least one track with a non-empty queue of text
  94   //                   buffers.
  95   // Return value - True indicates that the buffers are accepted.
  96   //                False if something was wrong with the buffers and a parsing
  97   //                error should be signalled.
  98   typedef base::Callback<bool(const BufferQueue&,
  99                               const BufferQueue&,
 100                               const TextBufferQueueMap&)> NewBuffersCB;
 101
 102   // Signals the beginning of a new media segment.
 103   typedef base::Callback<void()> NewMediaSegmentCB;
 104
 105   // A new potentially encrypted stream has been parsed.
 106   // First parameter - The type of the initialization data associated with the
 107   //                   stream.
 108   // Second parameter - The initialization data associated with the stream.
 109   typedef base::Callback<void(EmeInitDataType, const std::vector<uint8>&)>
 110       EncryptedMediaInitDataCB;
 111
 112   StreamParser();
 113   virtual ~StreamParser();
 114
 115   // Initializes the parser with necessary callbacks. Must be called before any
 116   // data is passed to Parse(). |init_cb| will be called once enough data has
 117   // been parsed to determine the initial stream configurations, presentation
 118   // start time, and duration. If |ignore_text_track| is true, then no text
 119   // buffers should be passed later by the parser to |new_buffers_cb|.
 120   virtual void Init(
 121       const InitCB& init_cb,
 122       const NewConfigCB& config_cb,
 123       const NewBuffersCB& new_buffers_cb,
 124       bool ignore_text_track,
 125       const EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
 126       const NewMediaSegmentCB& new_segment_cb,
 127       const base::Closure& end_of_segment_cb,
 128       const LogCB& log_cb) = 0;
 129
 130   // Called when a seek occurs. This flushes the current parser state
 131   // and puts the parser in a state where it can receive data for the new seek
 132   // point.
 133   virtual void Flush() = 0;
 134
 135   // Called when there is new data to parse.
 136   //
 137   // Returns true if the parse succeeds.
 138   virtual bool Parse(const uint8* buf, int size) = 0;
 139
 140  private:
 141   DISALLOW_COPY_AND_ASSIGN(StreamParser);
 142 };
 143
 144 // Appends to |merged_buffers| the provided buffers in decode-timestamp order.
 145 // Any previous contents of |merged_buffers| is assumed to have lower
 146 // decode timestamps versus the provided buffers. All provided buffer queues
 147 // are assumed to already be in decode-timestamp order.
 148 // Returns false if any of the provided audio/video/text buffers are found
 149 // to not be in decode timestamp order, or have a decode timestamp less than
 150 // the last buffer, if any, in |merged_buffers|. Partial results may exist
 151 // in |merged_buffers| in this case. Returns true on success.
 152 // No validation of media type within the various buffer queues is done here.
 153 // TODO(wolenetz/acolwell): Merge incrementally in parsers to eliminate
 154 // subtle issues with tie-breaking. See http://crbug.com/338484.
 155 MEDIA_EXPORT bool MergeBufferQueues(
 156     const StreamParser::BufferQueue& audio_buffers,
 157     const StreamParser::BufferQueue& video_buffers,
 158     const StreamParser::TextBufferQueueMap& text_buffers,
 159     StreamParser::BufferQueue* merged_buffers);
 160
 161 }  // namespace media
 162
 163 #endif  // MEDIA_BASE_STREAM_PARSER_H_