| // 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_ |
| |
| // NullAudioSink 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! |
| // |
| // NullAudioSink 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 <vector> |
| |
| #include "base/threading/thread.h" |
| #include "media/base/audio_renderer_sink.h" |
| |
| namespace media { |
| |
| class MEDIA_EXPORT NullAudioSink |
| : NON_EXPORTED_BASE(public AudioRendererSink) { |
| public: |
| NullAudioSink(); |
| |
| // AudioRendererSink implementation. |
| virtual void Initialize(const AudioParameters& params, |
| RenderCallback* callback) OVERRIDE; |
| virtual void Start() OVERRIDE; |
| virtual void Stop() OVERRIDE; |
| virtual void Pause(bool flush) OVERRIDE; |
| virtual void Play() OVERRIDE; |
| virtual void SetPlaybackRate(float rate) OVERRIDE; |
| virtual bool SetVolume(double volume) OVERRIDE; |
| virtual void GetVolume(double* volume) OVERRIDE; |
| |
| protected: |
| virtual ~NullAudioSink(); |
| |
| private: |
| // Audio thread task that periodically calls FillBuffer() to consume |
| // audio data. |
| void FillBufferTask(); |
| |
| void SetPlaying(bool is_playing); |
| |
| // A buffer passed to FillBuffer to advance playback. |
| std::vector<float*> audio_data_; |
| |
| AudioParameters params_; |
| bool initialized_; |
| float playback_rate_; |
| bool playing_; |
| RenderCallback* callback_; |
| |
| // Separate thread used to throw away data. |
| base::Thread thread_; |
| base::Lock lock_; |
| |
| DISALLOW_COPY_AND_ASSIGN(NullAudioSink); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_FILTERS_NULL_AUDIO_RENDERER_H_ |