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_AUDIO_SIMPLE_SOURCES_H_
6 #define MEDIA_AUDIO_SIMPLE_SOURCES_H_
8 #include "base/synchronization/lock.h"
9 #include "media/audio/audio_io.h"
10 #include "media/base/seekable_buffer.h"
14 // An audio source that produces a pure sinusoidal tone.
15 class MEDIA_EXPORT SineWaveAudioSource
16 : public AudioOutputStream::AudioSourceCallback
{
18 // |channels| is the number of audio channels, |freq| is the frequency in
19 // hertz and it has to be less than half of the sampling frequency
20 // |sample_freq| or else you will get aliasing.
21 SineWaveAudioSource(int channels
, double freq
, double sample_freq
);
22 virtual ~SineWaveAudioSource() {}
24 // Return up to |cap| samples of data via OnMoreData(). Use Reset() to
25 // allow more data to be served.
26 void CapSamples(int cap
);
29 // Implementation of AudioSourceCallback.
30 virtual int OnMoreData(AudioBus
* audio_bus
,
31 AudioBuffersState audio_buffers
) OVERRIDE
;
32 virtual void OnError(AudioOutputStream
* stream
) OVERRIDE
;
34 // The number of OnMoreData()+OnMoreIOData() and OnError() calls respectively.
35 int callbacks() { return callbacks_
; }
36 int errors() { return errors_
; }
45 base::Lock time_lock_
;
50 #endif // MEDIA_AUDIO_SIMPLE_SOURCES_H_