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 // MSVC++ requires this to be set before any other includes to get M_PI.
6 #define _USE_MATH_DEFINES
10 #include "media/base/fake_audio_render_callback.h"
14 FakeAudioRenderCallback::FakeAudioRenderCallback(double step
)
17 last_audio_delay_milliseconds_(-1),
22 FakeAudioRenderCallback::~FakeAudioRenderCallback() {}
24 int FakeAudioRenderCallback::Render(AudioBus
* audio_bus
,
25 int audio_delay_milliseconds
) {
26 last_audio_delay_milliseconds_
= audio_delay_milliseconds
;
27 int number_of_frames
= audio_bus
->frames();
29 number_of_frames
/= 2;
31 // Fill first channel with a sine wave.
32 for (int i
= 0; i
< number_of_frames
; ++i
)
33 audio_bus
->channel(0)[i
] = sin(2 * M_PI
* (x_
+ step_
* i
));
34 x_
+= number_of_frames
* step_
;
36 // Copy first channel into the rest of the channels.
37 for (int i
= 1; i
< audio_bus
->channels(); ++i
)
38 memcpy(audio_bus
->channel(i
), audio_bus
->channel(0),
39 number_of_frames
* sizeof(*audio_bus
->channel(i
)));
41 return number_of_frames
;
44 double FakeAudioRenderCallback::ProvideInput(AudioBus
* audio_bus
,
45 base::TimeDelta buffer_delay
) {
46 Render(audio_bus
, buffer_delay
.InMillisecondsF() + 0.5);