Fix MSE GC, make it less aggressive, more spec-compliant

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 <deque>
 #include <map>
 #include <string>
@@ skipping 38 matching lines @@
   // Removes buffers between |start| and |end| according to the steps
   // in the "Coded Frame Removal Algorithm" in the Media Source
   // Extensions Spec.
   // https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#sourcebuffer-coded-frame-removal
   //
   // |duration| is the current duration of the presentation. It is
   // required by the computation outlined in the spec.
   void Remove(base::TimeDelta start, base::TimeDelta end,
               base::TimeDelta duration);
 
+  // If the buffer is full, runs Frame Removal to try to free up space, as
+  // specified in the "Coded Frame Eviction Algorithm" in the Media Source
+  // Extensions Spec. Returns false iff buffer is still full after running
+  // eviction
+  // https://w3c.github.io/media-source/#sourcebuffer-coded-frame-eviction
+  bool EvictFrames(DecodeTimestamp media_time);
+
   // Signal to the stream that duration has changed to |duration|.
   void OnSetDuration(base::TimeDelta duration);
 
   // Returns the range of buffered data in this stream, capped at |duration|.
   Ranges<base::TimeDelta> GetBufferedRanges(base::TimeDelta duration) const;
 
   // Returns the duration of the buffered data.
   // Returns base::TimeDelta() if the stream has no buffered data.
   base::TimeDelta GetBufferedDuration() const;
 
@@ skipping 69 matching lines @@
 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.
   };
 
   typedef base::Closure InitSegmentReceivedCB;
 
+  typedef base::Callback<base::TimeDelta(void)> GetMediaTimeCB;
+
   // |open_cb| Run when Initialize() is called to signal that the demuxer
   //   is ready to receive media data via AppenData().
   // |encrypted_media_init_data_cb| Run when the demuxer determines that an
   //   encryption key is needed to decrypt the content.
   // |enable_text| Process inband text tracks in the normal way when true,
   //   otherwise ignore them.
   // |log_cb| Run when the demuxer needs to emit MediaLog messages.
+  // |get_media_time_cb| Should return current media playback time, which
+  //   is used to ensure unconsumed data in not garbage collected.

[wolenetz, 2015/06/04 00:38:57]

nit: s/in/is

[servolk, 2015/06/04 03:03:01]

Done.

   // |splice_frames_enabled| Indicates that it's okay to generate splice frames
   //   per the MSE specification.  Renderers must understand DecoderBuffer's
   //   splice_timestamp() field.
   ChunkDemuxer(const base::Closure& open_cb,
                const EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
                const LogCB& log_cb,
+               const GetMediaTimeCB& get_media_time_cb,
                const scoped_refptr<MediaLog>& media_log,
                bool splice_frames_enabled);
   ~ChunkDemuxer() override;
 
   // Demuxer implementation.
   void Initialize(DemuxerHost* host,
                   const PipelineStatusCB& cb,
                   bool enable_text_tracks) override;
   void Stop() override;
   void Seek(base::TimeDelta time, const PipelineStatusCB& cb) override;
@@ skipping 63 matching lines @@
   void Abort(const std::string& id,
              base::TimeDelta append_window_start,
              base::TimeDelta append_window_end,
              base::TimeDelta* timestamp_offset);
 
   // Remove buffers between |start| and |end| for the source buffer
   // associated with |id|.
   void Remove(const std::string& id, base::TimeDelta start,
               base::TimeDelta end);
 
+  bool EvictFrames();
+
   // Returns the current presentation duration.
   double GetDuration();
   double GetDuration_Locked();
 
   // Notifies the demuxer that the duration of the media has changed to
   // |duration|.
   void SetDuration(double duration);
 
   // Returns true if the source buffer associated with |id| is currently parsing
   // a media segment, or false otherwise.
@@ skipping 101 matching lines @@
   State state_;
   bool cancel_next_seek_;
 
   DemuxerHost* host_;
   base::Closure open_cb_;
   EncryptedMediaInitDataCB encrypted_media_init_data_cb_;
   bool enable_text_;
   // Callback used to report log messages that can help the web developer
   // figure out what is wrong with the content.
   LogCB log_cb_;
+  GetMediaTimeCB get_media_time_cb_;
   scoped_refptr<MediaLog> media_log_;
 
   PipelineStatusCB init_cb_;
   // Callback to execute upon seek completion.
   // TODO(wolenetz/acolwell): Protect against possible double-locking by first
   // releasing |lock_| before executing this callback. See
   // http://crbug.com/308226
   PipelineStatusCB seek_cb_;
 
   scoped_ptr<ChunkDemuxerStream> audio_;
@@ skipping 22 matching lines @@
 
   // Indicates that splice frame generation is enabled.
   const bool splice_frames_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(ChunkDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_CHUNK_DEMUXER_H_