1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef MEDIA_BASE_AUDIO_RENDERER_H_
6 #define MEDIA_BASE_AUDIO_RENDERER_H_
8 #include "base/callback.h"
9 #include "base/time/time.h"
10 #include "media/base/buffering_state.h"
11 #include "media/base/media_export.h"
12 #include "media/base/pipeline_status.h"
19 class MEDIA_EXPORT AudioRenderer
{
23 // Stop all operations and fire all pending callbacks.
24 virtual ~AudioRenderer();
26 // Initialize an AudioRenderer with |stream|, executing |init_cb| upon
29 // |statistics_cb| is executed periodically with audio rendering stats.
31 // |buffering_state_cb| is executed when audio rendering has either run out of
32 // data or has enough data to continue playback.
34 // |ended_cb| is executed when audio rendering has reached the end of stream.
36 // |error_cb| is executed if an error was encountered.
37 virtual void Initialize(DemuxerStream
* stream
,
38 const PipelineStatusCB
& init_cb
,
39 const StatisticsCB
& statistics_cb
,
40 const BufferingStateCB
& buffering_state_cb
,
41 const base::Closure
& ended_cb
,
42 const PipelineStatusCB
& error_cb
) = 0;
44 // Returns the TimeSource associated with audio rendering.
45 virtual TimeSource
* GetTimeSource() = 0;
47 // Discard any audio data, executing |callback| when completed.
49 // Clients should expect |buffering_state_cb| to be called with
50 // BUFFERING_HAVE_NOTHING while flushing is in progress.
51 virtual void Flush(const base::Closure
& callback
) = 0;
53 // Starts playback by reading from |stream| and decoding and rendering audio.
55 // Only valid to call after a successful Initialize() or Flush().
56 virtual void StartPlaying() = 0;
58 // Sets the output volume.
59 virtual void SetVolume(float volume
) = 0;
62 DISALLOW_COPY_AND_ASSIGN(AudioRenderer
);
67 #endif // MEDIA_BASE_AUDIO_RENDERER_H_