blob: bfb3c4df3789ff07ec2423050ce8f817f04bb7bd [file] [log] [blame]
// 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.
// MSVC++ requires this to be set before any other includes to get M_PI.
#define _USE_MATH_DEFINES
#include <cmath>
#include "media/base/audio_timestamp_helper.h"
#include "media/base/fake_audio_render_callback.h"
namespace media {
FakeAudioRenderCallback::FakeAudioRenderCallback(double step, int sample_rate)
: half_fill_(false),
step_(step),
last_delay_(base::TimeDelta::Max()),
last_channel_count_(-1),
volume_(1),
sample_rate_(sample_rate) {
reset();
}
FakeAudioRenderCallback::~FakeAudioRenderCallback() {}
int FakeAudioRenderCallback::Render(base::TimeDelta delay,
base::TimeTicks delay_timestamp,
int prior_frames_skipped,
AudioBus* audio_bus) {
return RenderInternal(audio_bus, delay, volume_);
}
double FakeAudioRenderCallback::ProvideInput(AudioBus* audio_bus,
uint32_t frames_delayed) {
// Volume should only be applied by the caller to ProvideInput, so don't bake
// it into the rendered audio.
auto delay = AudioTimestampHelper::FramesToTime(frames_delayed, sample_rate_);
RenderInternal(audio_bus, delay, 1.0);
return volume_;
}
int FakeAudioRenderCallback::RenderInternal(AudioBus* audio_bus,
base::TimeDelta delay,
double volume) {
DCHECK_LE(delay, base::TimeDelta::Max());
last_delay_ = delay;
last_channel_count_ = audio_bus->channels();
int number_of_frames = audio_bus->frames();
if (half_fill_)
number_of_frames /= 2;
// Fill first channel with a sine wave.
for (int i = 0; i < number_of_frames; ++i)
audio_bus->channel(0)[i] = sin(2 * M_PI * (x_ + step_ * i)) * volume;
x_ += number_of_frames * step_;
// Copy first channel into the rest of the channels.
for (int i = 1; i < audio_bus->channels(); ++i) {
memcpy(audio_bus->channel(i), audio_bus->channel(0),
number_of_frames * sizeof(*audio_bus->channel(i)));
}
return number_of_frames;
}
} // namespace media