Allow multiple concurrent Decode() requests in VideoDecoder interface.

media/filters/decoder_stream.h

 // Copyright 2014 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_DECODER_STREAM_H_
 #define MEDIA_FILTERS_DECODER_STREAM_H_
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
@@ skipping 69 matching lines @@
   // it is stopped. This method can be called at any time but not during another
   // pending Stop().
   void Stop(const base::Closure& closure);
 
   // Returns true if the decoder currently has the ability to decode and return
   // an Output.
   // TODO(rileya): Remove the need for this by refactoring Decoder queueing
   // behavior.
   bool CanReadWithoutStalling() const;
 
+  // Returns true if one more decode request can be submitted to the decoder.
+  bool CanDecodeAnotherBuffer() const;

[xhwang, 2014/04/25 00:36:03]

nit: how about CanDecodeMore()?

[Sergey Ulanov, 2014/04/26 00:59:29]

Done.

+
   // Allows callers to register for notification of splice buffers from the
   // demuxer.  I.e., DecoderBuffer::splice_timestamp() is not kNoTimestamp().
   //
   // The observer will be notified of all buffers with a splice_timestamp() and
   // the first buffer after which has a splice_timestamp() of kNoTimestamp().
   typedef base::Callback<void(base::TimeDelta)> SpliceObserverCB;
   void set_splice_observer(const SpliceObserverCB& splice_observer) {
     splice_observer_cb_ = splice_observer;
   }
 
@@ skipping 22 matching lines @@
   // |decrypting_demuxer_stream| was also populated if a DecryptingDemuxerStream
   // is created to help decrypt the encrypted stream.
   void OnDecoderSelected(
       scoped_ptr<Decoder> selected_decoder,
       scoped_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream);
 
   // Satisfy pending |read_cb_| with |status| and |output|.
   void SatisfyRead(Status status,
                    const scoped_refptr<Output>& output);
 
-  // Abort pending |read_cb_|.
-  void AbortRead();
-
   // Decodes |buffer| and returns the result via OnDecodeOutputReady().
   void Decode(const scoped_refptr<DecoderBuffer>& buffer);
 
   // Flushes the decoder with an EOS buffer to retrieve internally buffered
   // decoder output.
   void FlushDecoder();
 
   // Callback for Decoder::Decode().
   void OnDecodeOutputReady(int buffer_size,
                            DecoderStatus status,
@@ skipping 13 matching lines @@
 
   void ResetDecoder();
   void OnDecoderReset();
 
   void StopDecoder();
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   State state_;
 
+  // Error code when state_ == STATE_ERROR.
+  Status error_;

[xhwang, 2014/04/25 00:36:03]

DECRYPT_ERROR is going to be deprecated. When state_ is ERROR, you can just
return DECODE_ERROR in ReadCBs.

[Sergey Ulanov, 2014/04/26 00:59:29]

Done.

+
   StatisticsCB statistics_cb_;
   InitCB init_cb_;
 
   ReadCB read_cb_;
   base::Closure reset_cb_;
   base::Closure stop_cb_;
 
   DemuxerStream* stream_;
 
   scoped_ptr<DecoderSelector<StreamType> > decoder_selector_;
 
   // These two will be set by DecoderSelector::SelectDecoder().
   scoped_ptr<Decoder> decoder_;
   scoped_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream_;
 
   SpliceObserverCB splice_observer_cb_;
   ConfigChangeObserverCB config_change_observer_cb_;
 
   // If a splice_timestamp() has been seen, this is true until a
   // splice_timestamp() of kNoTimestamp() is encountered.
   bool active_splice_;
 
+  // Decoded buffers that haven't been read yet. Used when the decoder supports
+  // parallel decoding.
+  std::list<scoped_refptr<Output> > ready_outputs_;
+  int pending_decode_requests_;

[xhwang, 2014/04/25 00:36:03]

This worth a separate comment.

[Sergey Ulanov, 2014/04/26 00:59:29]

Done.

+
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<DecoderStream<StreamType> > weak_factory_;
 
   // This is required so the VideoFrameStream can access private members in
   // FinishInitialization() and ReportStatistics().
   DISALLOW_IMPLICIT_CONSTRUCTORS(DecoderStream);
 };
 
 template <>
 bool DecoderStream<DemuxerStream::AUDIO>::CanReadWithoutStalling() const;
 
+template <>
+bool DecoderStream<DemuxerStream::AUDIO>::CanDecodeAnotherBuffer() const;
+
 typedef DecoderStream<DemuxerStream::VIDEO> VideoFrameStream;
 typedef DecoderStream<DemuxerStream::AUDIO> AudioBufferStream;
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_DECODER_STREAM_H_