Add AudioBufferStream.

media/base/audio_decoder.h

Index: media/base/audio_decoder.h
diff --git a/media/base/audio_decoder.h b/media/base/audio_decoder.h
index 5aefb84aa67e486971f5836cbdccb3e338abdb08..3795b37c7000eefa226fb5302226ed71f66d3c8e 100644
--- a/media/base/audio_decoder.h
+++ b/media/base/audio_decoder.h
@@ -7,9 +7,11 @@
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
+#include "media/base/audio_decoder_config.h"
 #include "media/base/channel_layout.h"
-#include "media/base/pipeline_status.h"
+#include "media/base/decoder_buffer.h"
 #include "media/base/media_export.h"
+#include "media/base/pipeline_status.h"
 
 namespace media {
 
@@ -18,11 +20,15 @@ class DemuxerStream;
 
 class MEDIA_EXPORT AudioDecoder {
  public:
-  // Status codes for read operations.
+  // Status codes for decode operations.
+  // TODO(rileya): Now that both AudioDecoder and VideoDecoder Status enums
+  // match, break them into a decoder_status.h.
   enum Status {
-    kOk,
-    kAborted,
-    kDecodeError,
+    kOk,  // We're all good.
+    kAborted,  // We aborted as a result of Stop() or Reset().
+    kNotEnoughData,  // Not enough data to produce a video frame.
+    kDecodeError,  // A decoding error occurred.
+    kDecryptError  // Decrypting error happened.
   };
 
   AudioDecoder();
@@ -31,9 +37,8 @@ class MEDIA_EXPORT AudioDecoder {
   // Initializes an AudioDecoder with the given DemuxerStream, executing the
   // callback upon completion.
   // statistics_cb is used to update global pipeline statistics.
-  virtual void Initialize(DemuxerStream* stream,
-                          const PipelineStatusCB& status_cb,
-                          const StatisticsCB& statistics_cb) = 0;
+  virtual void Initialize(const AudioDecoderConfig& config,
+                          const PipelineStatusCB& status_cb) = 0;
 
   // Requests samples to be decoded and returned via the provided callback.
   // Only one read may be in flight at any given time.
@@ -46,8 +51,14 @@ class MEDIA_EXPORT AudioDecoder {
   // Read(). This can happen if the DemuxerStream gets flushed and doesn't have
   // any more data to return.
   typedef base::Callback<void(Status, const scoped_refptr<AudioBuffer>&)>
-      ReadCB;
-  virtual void Read(const ReadCB& read_cb) = 0;
+      DecodeCB;
+  virtual void Decode(const scoped_refptr<DecoderBuffer>& buffer,
+                      const DecodeCB& decode_cb) = 0;
+
+  // Some AudioDecoders will queue up multiple AudioBuffers from a single
+  // DecoderBuffer, if we have any such queued buffers this will return the next
+  // one. Otherwise we return a NULL AudioBuffer.
+  virtual scoped_refptr<AudioBuffer> GetAudioBuffer(Status* status);

[xhwang, 2014/02/27 19:52:28]

I wonder shouldn't this |status| always be kOk? We shouldn't call this function
if the decoder is pending reset or stop in the first place. I may miss something
here though...

 
   // Resets decoder state, dropping any queued encoded data.
   virtual void Reset(const base::Closure& closure) = 0;