| // 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_RENDERER_H_ |
| #define MEDIA_BASE_AUDIO_RENDERER_H_ |
| |
| #include "base/callback.h" |
| #include "base/time/time.h" |
| #include "media/base/buffering_state.h" |
| #include "media/base/media_export.h" |
| #include "media/base/pipeline_status.h" |
| |
| namespace media { |
| |
| class DemuxerStream; |
| class TimeSource; |
| |
| class MEDIA_EXPORT AudioRenderer { |
| public: |
| // First parameter is the current time that has been rendered. |
| // Second parameter is the maximum time value that the clock cannot exceed. |
| typedef base::Callback<void(base::TimeDelta, base::TimeDelta)> TimeCB; |
| |
| AudioRenderer(); |
| |
| // Stop all operations and fire all pending callbacks. |
| virtual ~AudioRenderer(); |
| |
| // Initialize an AudioRenderer with |stream|, executing |init_cb| upon |
| // completion. |
| // |
| // |statistics_cb| is executed periodically with audio rendering stats. |
| // |
| // |time_cb| is executed whenever time has advanced by way of audio rendering. |
| // |
| // |buffering_state_cb| is executed when audio rendering has either run out of |
| // data or has enough data to continue playback. |
| // |
| // |ended_cb| is executed when audio rendering has reached the end of stream. |
| // |
| // |error_cb| is executed if an error was encountered. |
| virtual void Initialize(DemuxerStream* stream, |
| const PipelineStatusCB& init_cb, |
| const StatisticsCB& statistics_cb, |
| const TimeCB& time_cb, |
| const BufferingStateCB& buffering_state_cb, |
| const base::Closure& ended_cb, |
| const PipelineStatusCB& error_cb) = 0; |
| |
| // Returns the TimeSource associated with audio rendering. |
| virtual TimeSource* GetTimeSource() = 0; |
| |
| // Discard any audio data, executing |callback| when completed. |
| // |
| // Clients should expect |buffering_state_cb| to be called with |
| // BUFFERING_HAVE_NOTHING while flushing is in progress. |
| virtual void Flush(const base::Closure& callback) = 0; |
| |
| // Starts playback by reading from |stream| and decoding and rendering audio. |
| // |
| // Only valid to call after a successful Initialize() or Flush(). |
| virtual void StartPlaying() = 0; |
| |
| // Sets the output volume. |
| virtual void SetVolume(float volume) = 0; |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(AudioRenderer); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_BASE_AUDIO_RENDERER_H_ |