Add status parameter to DemuxerStream::ReadCB

media/base/audio_decoder.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_BASE_AUDIO_DECODER_H_
 #define MEDIA_BASE_AUDIO_DECODER_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "media/base/channel_layout.h"
 #include "media/base/pipeline_status.h"
 #include "media/base/media_export.h"
 
 namespace media {
 
 class Buffer;
 class DemuxerStream;
 
 class MEDIA_EXPORT AudioDecoder
     : public base::RefCountedThreadSafe<AudioDecoder> {
  public:
+  // Status codes for read operations.
+  enum Status {
+    kOk,  // Everything went as planned.
+    kAborted, // Read was aborted early.
+    kDecodeError,  // Decoding error happened.

[Ami GONE FROM CHROMIUM, 2012/06/26 00:33:21]

These comments aren't adding much value.

[acolwell GONE FROM CHROMIUM, 2012/07/12 01:19:38]

Done.

+  };
+
   // Initialize an AudioDecoder with the given DemuxerStream, executing the
   // callback upon completion.
   // statistics_cb is used to update global pipeline statistics.
   virtual void Initialize(const scoped_refptr<DemuxerStream>& stream,
                           const PipelineStatusCB& status_cb,
                           const StatisticsCB& statistics_cb) = 0;
 
   // Request samples to be decoded and returned via the provided callback.
   // Only one read may be in flight at any given time.
   //
   // Implementations guarantee that the callback will not be called from within
   // this method.
   //
   // Non-NULL sample buffer pointers will contain decoded audio data or may
   // indicate the end of the stream. A NULL buffer pointer indicates an aborted
   // Read(). This can happen if the DemuxerStream gets flushed and doesn't have
   // any more data to return.
-  typedef base::Callback<void(scoped_refptr<Buffer>)> ReadCB;
+  typedef base::Callback<void(Status, const scoped_refptr<Buffer>&)> ReadCB;
   virtual void Read(const ReadCB& read_cb) = 0;
 
   // Reset decoder state, dropping any queued encoded data.
   virtual void Reset(const base::Closure& closure) = 0;
 
   // Returns various information about the decoded audio format.
   virtual int bits_per_channel() = 0;
   virtual ChannelLayout channel_layout() = 0;
   virtual int samples_per_second() = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<AudioDecoder>;
   virtual ~AudioDecoder();
   AudioDecoder();
 
   DISALLOW_COPY_AND_ASSIGN(AudioDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_DECODER_H_