Chrome-side implementation of media source timestamp offset

media/filters/chunk_demuxer.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_FILTERS_CHUNK_DEMUXER_H_
 #define MEDIA_FILTERS_CHUNK_DEMUXER_H_
 
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/synchronization/lock.h"
 #include "media/base/byte_queue.h"
 #include "media/base/demuxer.h"
 #include "media/base/ranges.h"
 #include "media/base/stream_parser.h"
 #include "media/filters/source_buffer_stream.h"
 
 namespace media {
 
 class ChunkDemuxerClient;
 class ChunkDemuxerStream;
 class FFmpegURLProtocol;
+class SourceInfo;
 
 // Demuxer implementation that allows chunks of media data to be passed
 // from JavaScript to the media stack.
 class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
  public:
   enum Status {
     kOk,              // ID added w/o error.
     kNotSupported,    // Type specified is not supported.
     kReachedIdLimit,  // Reached ID limit. We can't handle any more IDs.
   };
@@ skipping 32 matching lines @@
   Ranges<base::TimeDelta> GetBufferedRanges(const std::string& id) const;
 
   // Appends media data to the source buffer associated with |id|. Returns
   // false if this method is called in an invalid state.
   bool AppendData(const std::string& id, const uint8* data, size_t length);
 
   // Aborts parsing the current segment and reset the parser to a state where
   // it can accept a new segment.
   void Abort(const std::string& id);
 
+  // Sets a time |offset| in seconds to be applied to subsequent buffers
+  // appended to the source buffer assicated with |id|.
+  bool TimestampOffset(const std::string& id, float offset);

[acolwell GONE FROM CHROMIUM, 2012/07/20 18:21:01]

nit: SetTimestampOffset()?

[vrk (LEFT CHROMIUM), 2012/07/25 17:16:48]

Done, and changed other similar methods.

+
   // Signals an EndOfStream request.
   // Returns false if called in an unexpected state or if there is a gap between
   // the current position and the end of the buffered data.
   bool EndOfStream(PipelineStatus status);
   void Shutdown();
 
  protected:
   virtual ~ChunkDemuxer();
 
  private:
@@ skipping 23 matching lines @@
   // StreamParser callbacks.
   void OnStreamParserInitDone(bool success, base::TimeDelta duration);
   bool OnNewConfigs(bool has_audio, bool has_video,
                     const AudioDecoderConfig& audio_config,
                     const VideoDecoderConfig& video_config);
   bool OnAudioBuffers(const StreamParser::BufferQueue& buffers);
   bool OnVideoBuffers(const StreamParser::BufferQueue& buffers);
   bool OnNeedKey(scoped_array<uint8> init_data, int init_data_size);
   void OnNewMediaSegment(const std::string& source_id,
                          base::TimeDelta start_timestamp);
+  void OnEndOfMediaSegment(const std::string& source_id);
 
   // Computes the intersection between the video & audio
   // buffered ranges.
   Ranges<base::TimeDelta> ComputeIntersection() const;
 
+  // Applies |time_offset| to the timestamps of |buffers|.
+  void AdjustBufferTimestamps(const StreamParser::BufferQueue& buffers,
+                              base::TimeDelta timestamp_offset);
+
   mutable base::Lock lock_;
   State state_;
 
   DemuxerHost* host_;
   ChunkDemuxerClient* client_;
   PipelineStatusCB init_cb_;
   PipelineStatusCB seek_cb_;
 
   scoped_refptr<ChunkDemuxerStream> audio_;
   scoped_refptr<ChunkDemuxerStream> video_;
 
   base::TimeDelta duration_;
 
   typedef std::map<std::string, StreamParser*> StreamParserMap;
   StreamParserMap stream_parser_map_;
 
+  // Contains state belonging to a media source.
+  struct StreamInfo {

[acolwell GONE FROM CHROMIUM, 2012/07/20 18:21:01]

nit: s/StreamInfo/SourceInfo or SourceIdInfo since this is source buffer
specific not stream specific?

[vrk (LEFT CHROMIUM), 2012/07/25 17:16:48]

Done.

+    base::TimeDelta timestamp_offset;
+    bool can_update_offset;
+  };
+  typedef std::map<std::string, StreamInfo> StreamInfoMap;
+  StreamInfoMap stream_info_map_;
+
   // Used to ensure that (1) config data matches the type and codec provided in
   // AddId(), (2) only 1 audio and 1 video sources are added, and (3) ids may be
   // removed with RemoveID() but can not be re-added (yet).
   std::string source_id_audio_;
   std::string source_id_video_;
 
   base::TimeDelta start_time_;
 
   DISALLOW_COPY_AND_ASSIGN(ChunkDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_CHUNK_DEMUXER_H_