| // 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. |
| |
| #include "media/base/fake_audio_render_callback.h" |
| |
| #include "base/numerics/math_constants.h" |
| #include "media/base/audio_timestamp_helper.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() = default; |
| |
| 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 * base::kPiDouble * (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 |