Browse Source
Merge pull request #8134 from Tachi107/remove-time-stretcher
Merge pull request #8134 from Tachi107/remove-time-stretcher
audio_core: remove time stretcherpull/15/merge
merry
4 years ago
committed by
GitHub
GitHub
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
9 changed files with 3 additions and 144 deletions
-
3.gitmodules
-
3externals/CMakeLists.txt
-
1externals/soundtouch
-
3src/audio_core/CMakeLists.txt
-
25src/audio_core/cubeb_sink.cpp
-
4src/audio_core/sdl2_sink.cpp
-
68src/audio_core/time_stretch.cpp
-
34src/audio_core/time_stretch.h
-
6src/yuzu_cmd/default_ini.h
@ -1,68 +0,0 @@ |
|||
// Copyright 2018 yuzu Emulator Project
|
|||
// Licensed under GPLv2 or any later version
|
|||
// Refer to the license.txt file included.
|
|||
|
|||
#include <algorithm>
|
|||
#include <cmath>
|
|||
#include <cstddef>
|
|||
#include "audio_core/time_stretch.h"
|
|||
#include "common/logging/log.h"
|
|||
|
|||
namespace AudioCore { |
|||
|
|||
TimeStretcher::TimeStretcher(u32 sample_rate, u32 channel_count) : m_sample_rate{sample_rate} { |
|||
m_sound_touch.setChannels(channel_count); |
|||
m_sound_touch.setSampleRate(sample_rate); |
|||
m_sound_touch.setPitch(1.0); |
|||
m_sound_touch.setTempo(1.0); |
|||
} |
|||
|
|||
void TimeStretcher::Clear() { |
|||
m_sound_touch.clear(); |
|||
} |
|||
|
|||
void TimeStretcher::Flush() { |
|||
m_sound_touch.flush(); |
|||
} |
|||
|
|||
std::size_t TimeStretcher::Process(const s16* in, std::size_t num_in, s16* out, |
|||
std::size_t num_out) { |
|||
const double time_delta = static_cast<double>(num_out) / m_sample_rate; // seconds
|
|||
|
|||
// We were given actual_samples number of samples, and num_samples were requested from us.
|
|||
double current_ratio = static_cast<double>(num_in) / static_cast<double>(num_out); |
|||
|
|||
const double max_latency = 0.25; // seconds
|
|||
const double max_backlog = m_sample_rate * max_latency; |
|||
const double backlog_fullness = m_sound_touch.numSamples() / max_backlog; |
|||
if (backlog_fullness > 4.0) { |
|||
// Too many samples in backlog: Don't push anymore on
|
|||
num_in = 0; |
|||
} |
|||
|
|||
// We ideally want the backlog to be about 50% full.
|
|||
// This gives some headroom both ways to prevent underflow and overflow.
|
|||
// We tweak current_ratio to encourage this.
|
|||
constexpr double tweak_time_scale = 0.05; // seconds
|
|||
const double tweak_correction = (backlog_fullness - 0.5) * (time_delta / tweak_time_scale); |
|||
current_ratio *= std::pow(1.0 + 2.0 * tweak_correction, tweak_correction < 0 ? 3.0 : 1.0); |
|||
|
|||
// This low-pass filter smoothes out variance in the calculated stretch ratio.
|
|||
// The time-scale determines how responsive this filter is.
|
|||
constexpr double lpf_time_scale = 0.712; // seconds
|
|||
const double lpf_gain = 1.0 - std::exp(-time_delta / lpf_time_scale); |
|||
m_stretch_ratio += lpf_gain * (current_ratio - m_stretch_ratio); |
|||
|
|||
// Place a lower limit of 5% speed. When a game boots up, there will be
|
|||
// many silence samples. These do not need to be timestretched.
|
|||
m_stretch_ratio = std::max(m_stretch_ratio, 0.05); |
|||
m_sound_touch.setTempo(m_stretch_ratio); |
|||
|
|||
LOG_TRACE(Audio, "{:5}/{:5} ratio:{:0.6f} backlog:{:0.6f}", num_in, num_out, m_stretch_ratio, |
|||
backlog_fullness); |
|||
|
|||
m_sound_touch.putSamples(in, static_cast<u32>(num_in)); |
|||
return m_sound_touch.receiveSamples(out, static_cast<u32>(num_out)); |
|||
} |
|||
|
|||
} // namespace AudioCore
|
|||
@ -1,34 +0,0 @@ |
|||
// Copyright 2018 yuzu Emulator Project |
|||
// Licensed under GPLv2 or any later version |
|||
// Refer to the license.txt file included. |
|||
|
|||
#pragma once |
|||
|
|||
#include <cstddef> |
|||
#include <SoundTouch.h> |
|||
#include "common/common_types.h" |
|||
|
|||
namespace AudioCore { |
|||
|
|||
class TimeStretcher { |
|||
public: |
|||
TimeStretcher(u32 sample_rate, u32 channel_count); |
|||
|
|||
/// @param in Input sample buffer |
|||
/// @param num_in Number of input frames in `in` |
|||
/// @param out Output sample buffer |
|||
/// @param num_out Desired number of output frames in `out` |
|||
/// @returns Actual number of frames written to `out` |
|||
std::size_t Process(const s16* in, std::size_t num_in, s16* out, std::size_t num_out); |
|||
|
|||
void Clear(); |
|||
|
|||
void Flush(); |
|||
|
|||
private: |
|||
u32 m_sample_rate; |
|||
soundtouch::SoundTouch m_sound_touch; |
|||
double m_stretch_ratio = 1.0; |
|||
}; |
|||
|
|||
} // namespace AudioCore |
|||
Write
Preview
Loading…
Cancel
Save
Reference in new issue