Merge AudioRendererImpl and AudioRendererBase; add NullAudioSink

media/filters/null_audio_renderer.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_FILTERS_NULL_AUDIO_RENDERER_H_
-#define MEDIA_FILTERS_NULL_AUDIO_RENDERER_H_
-
-// NullAudioRenderer effectively uses an extra thread to "throw away" the
-// audio data at a rate resembling normal playback speed.  It's just like
-// decoding to /dev/null!
-//
-// NullAudioRenderer can also be used in situations where the client has no
-// audio device or we haven't written an audio implementation for a particular
-// platform yet.
-
-#include <deque>
-
-#include "base/memory/scoped_ptr.h"
-#include "base/threading/thread.h"
-#include "media/base/buffers.h"
-#include "media/base/filters.h"
-#include "media/filters/audio_renderer_base.h"
-
-namespace media {
-
-class MEDIA_EXPORT NullAudioRenderer : public AudioRendererBase {
- public:
-  NullAudioRenderer();
-  virtual ~NullAudioRenderer();
-
-  // AudioRenderer implementation.
-  virtual void SetVolume(float volume) OVERRIDE;
-
- protected:
-  // AudioRendererBase implementation.
-  virtual bool OnInitialize(int bits_per_channel,
-                            ChannelLayout channel_layout,
-                            int sample_rate) OVERRIDE;
-  virtual void OnStop() OVERRIDE;
-  virtual void OnRenderEndOfStream() OVERRIDE;
-
- private:
-  // Audio thread task that periodically calls FillBuffer() to consume
-  // audio data.
-  void FillBufferTask();
-
-  // A number to convert bytes written in FillBuffer to milliseconds based on
-  // the audio format.
-  size_t bytes_per_millisecond_;
-
-  // A buffer passed to FillBuffer to advance playback.
-  scoped_array<uint8> buffer_;
-  size_t buffer_size_;
-
-  size_t bytes_per_frame_;
-
-  // Separate thread used to throw away data.
-  base::Thread thread_;
-
-  DISALLOW_COPY_AND_ASSIGN(NullAudioRenderer);
-};
-
-}  // namespace media
-
-#endif  // MEDIA_FILTERS_NULL_AUDIO_RENDERER_H_