Separate DemuxerStream and VideoDecoder.

media/filters/video_frame_stream.h

 // Copyright (c) 2013 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_VIDEO_FRAME_STREAM_H_
 #define MEDIA_FILTERS_VIDEO_FRAME_STREAM_H_
 
-#include <list>
-
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "media/base/decryptor.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/media_export.h"
 #include "media/base/pipeline_status.h"
 #include "media/base/video_decoder.h"
 
 namespace base {
 class MessageLoopProxy;
 }
 
 namespace media {
 
 class DecryptingDemuxerStream;
 class VideoDecoderSelector;
 
 // Wraps a DemuxerStream and a list of VideoDecoders and provides decoded
 // VideoFrames to its client (e.g. VideoRendererBase).
-class MEDIA_EXPORT VideoFrameStream : public DemuxerStream {
+class MEDIA_EXPORT VideoFrameStream {
  public:
   // Indicates completion of VideoFrameStream initialization.
   typedef base::Callback<void(bool success, bool has_alpha)> InitCB;
 
   VideoFrameStream(const scoped_refptr<base::MessageLoopProxy>& message_loop,
                    ScopedVector<VideoDecoder> decoders,
                    const SetDecryptorReadyCB& set_decryptor_ready_cb);
   virtual ~VideoFrameStream();
 
   // Initializes the VideoFrameStream and returns the initialization result
   // through |init_cb|. Note that |init_cb| is always called asynchronously.
   void Initialize(DemuxerStream* stream,
                   const StatisticsCB& statistics_cb,
                   const InitCB& init_cb);
 
   // Reads a decoded VideoFrame and returns it via the |read_cb|. Note that
   // |read_cb| is always called asynchronously. This method should only be
   // called after initialization has succeeded and must not be called during
   // any pending Reset() and/or Stop().
+  // TODO(xhwang): Rename this back to Read().
   void ReadFrame(const VideoDecoder::ReadCB& read_cb);
 
   // Resets the decoder, flushes all decoded frames and/or internal buffers,
   // fires any existing pending read callback and calls |closure| on completion.
   // Note that |closure| is always called asynchronously. This method should
   // only be called after initialization has succeeded and must not be called
   // during any pending Reset() and/or Stop().
   void Reset(const base::Closure& closure);
 
   // Stops the decoder, fires any existing pending read callback or reset
   // callback and calls |closure| on completion. Note that |closure| is always
   // called asynchronously. The VideoFrameStream cannot be used anymore after
   // 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
   // a VideoFrame.
   bool CanReadWithoutStalling() const;
 
-  // DemuxerStream implementation.
-  virtual void Read(const ReadCB& read_cb) OVERRIDE;
-  virtual AudioDecoderConfig audio_decoder_config() OVERRIDE;
-  virtual VideoDecoderConfig video_decoder_config() OVERRIDE;
-  virtual Type type() OVERRIDE;
-  virtual void EnableBitstreamConverter() OVERRIDE;
-
  private:
   enum State {
     STATE_UNINITIALIZED,
     STATE_INITIALIZING,
-    STATE_NORMAL,
+    STATE_NORMAL,  // Includes idle, pending decoder decode/reset/stop.
     STATE_FLUSHING_DECODER,
+    STATE_PENDING_DEMUXER_READ,
     STATE_REINITIALIZING_DECODER,
     STATE_STOPPED,
     STATE_ERROR
   };
 
   // Called when |decoder_selector| selected the |selected_decoder|.
   // |decrypting_demuxer_stream| was also populated if a DecryptingDemuxerStream
   // is created to help decrypt the encrypted stream.
   void OnDecoderSelected(
       scoped_ptr<VideoDecoder> selected_decoder,
       scoped_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream);
 
-  // Callback for VideoDecoder::Read().
+  // Satisfy pending |read_cb_| with |status| and |frame|.
+  void SatisfyRead(VideoDecoder::Status status,
+                   const scoped_refptr<VideoFrame>& frame);
+
+  // Abort pending |read_cb_|.
+  void AbortRead();
+
+  // Decodes |buffer| and returns the result via OnFrameReady().
+  void Decode(const scoped_refptr<DecoderBuffer>& buffer);
+
+  // Flushes the decoder with an EOS buffer to retrieve internally buffered
+  // video frames.
+  void FlushDecoder();
+
+  // Callback for VideoDecoder::Decode().
   void OnFrameReady(const VideoDecoder::Status status,
                     const scoped_refptr<VideoFrame>& frame);
 
+  // Reads a buffer from |stream_| and returns the result via OnBufferReady().
+  void ReadFromDemuxerStream();
+
   // Callback for DemuxerStream::Read().
-  void OnBufferReady(const DemuxerStream::ReadCB& demuxer_read_cb,
-                     DemuxerStream::Status status,
+  void OnBufferReady(DemuxerStream::Status status,
                      const scoped_refptr<DecoderBuffer>& buffer);
 
   void ReinitializeDecoder();
 
   // Callback for VideoDecoder reinitialization.
   void OnDecoderReinitialized(PipelineStatus status);
 
   void ResetDecoder();
   void OnDecoderReset();
 
@@ skipping 20 matching lines @@
   // These two will be set by VideoDecoderSelector::SelectVideoDecoder().
   scoped_ptr<VideoDecoder> decoder_;
   scoped_ptr<DecryptingDemuxerStream> decrypting_demuxer_stream_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoFrameStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_VIDEO_FRAME_STREAM_H_