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.
4
5 // MSVC++ requires this to be set before any other includes to get M_PI.
6 #define _USE_MATH_DEFINES
7
8 #include <cmath>
9
10 #include "media/base/fake_audio_render_callback.h"
11
12 namespace media {
13
FakeAudioRenderCallback(double step)14 FakeAudioRenderCallback::FakeAudioRenderCallback(double step)
15 : half_fill_(false),
16 step_(step),
17 last_audio_delay_milliseconds_(-1),
18 volume_(1) {
19 reset();
20 }
21
~FakeAudioRenderCallback()22 FakeAudioRenderCallback::~FakeAudioRenderCallback() {}
23
Render(AudioBus * audio_bus,int audio_delay_milliseconds)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();
28 if (half_fill_)
29 number_of_frames /= 2;
30
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_;
35
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)));
40
41 return number_of_frames;
42 }
43
ProvideInput(AudioBus * audio_bus,base::TimeDelta buffer_delay)44 double FakeAudioRenderCallback::ProvideInput(AudioBus* audio_bus,
45 base::TimeDelta buffer_delay) {
46 Render(audio_bus, buffer_delay.InMillisecondsF() + 0.5);
47 return volume_;
48 }
49
50 } // namespace media
51