| // Copyright 2012 The Chromium Authors |
| // 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 <algorithm> |
| #include <numbers> |
| |
| #include "base/time/time.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, |
| const AudioGlitchInfo& glitch_info, |
| AudioBus* audio_bus) { |
| cumulative_glitch_info_ += glitch_info; |
| return RenderInternal(audio_bus, delay, volume_); |
| } |
| |
| double FakeAudioRenderCallback::ProvideInput( |
| AudioBus* audio_bus, |
| uint32_t frames_delayed, |
| const AudioGlitchInfo& glitch_info) { |
| cumulative_glitch_info_ += glitch_info; |
| // 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; |
| |
| float* channel_data = audio_bus->channel(0); |
| |
| // Fill first channel with a sine wave. |
| for (int i = 0; i < number_of_frames; ++i) { |
| channel_data[i] = sin(2 * std::numbers::pi * (x_ + step_ * i)) * volume; |
| } |
| x_ += number_of_frames * step_; |
| |
| // Matches the AudioRenderer::InputFadeInHelper implementation. |
| if (needs_fade_in_) { |
| constexpr base::TimeDelta kFadeInDuration = base::Milliseconds(5); |
| |
| const int fade_in_frames = |
| std::min(static_cast<int>(AudioTimestampHelper::TimeToFrames( |
| kFadeInDuration, sample_rate_)), |
| audio_bus->frames()); |
| |
| for (int i = 0; i < fade_in_frames; ++i) |
| channel_data[i] = channel_data[i] * i / fade_in_frames; |
| |
| needs_fade_in_ = false; |
| } |
| |
| // 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 |