Allow multiple concurrent Decode() requests in VideoDecoder interface.

media/filters/decoder_stream.h

Index: media/filters/decoder_stream.h
diff --git a/media/filters/decoder_stream.h b/media/filters/decoder_stream.h
index 4992141443b3410d71c050318fb2b160807a870b..f719d876b9253048f68de2f61223e553c379c9aa 100644
--- a/media/filters/decoder_stream.h
+++ b/media/filters/decoder_stream.h
@@ -87,6 +87,9 @@ class MEDIA_EXPORT DecoderStream {
   // 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().
   //
@@ -129,9 +132,6 @@ class MEDIA_EXPORT DecoderStream {
   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);
 
@@ -165,6 +165,9 @@ class MEDIA_EXPORT DecoderStream {
 
   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_;
 
@@ -187,6 +190,11 @@ class MEDIA_EXPORT DecoderStream {
   // 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_;
 
@@ -198,6 +206,9 @@ class MEDIA_EXPORT 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;