diff options
author | Andrea Pappacoda <andrea@pappacoda.it> | 2022-04-01 19:54:58 +0200 |
---|---|---|
committer | Andrea Pappacoda <andrea@pappacoda.it> | 2022-04-01 19:54:58 +0200 |
commit | faf6a9876c394664d647355726290014b24efffc (patch) | |
tree | d6dca0d742af8ccc9443e77583b3c6e51d2841ac /src/audio_core/time_stretch.cpp | |
parent | Merge pull request #8128 from FernandoS27/gc-fixes (diff) | |
download | yuzu-faf6a9876c394664d647355726290014b24efffc.tar yuzu-faf6a9876c394664d647355726290014b24efffc.tar.gz yuzu-faf6a9876c394664d647355726290014b24efffc.tar.bz2 yuzu-faf6a9876c394664d647355726290014b24efffc.tar.lz yuzu-faf6a9876c394664d647355726290014b24efffc.tar.xz yuzu-faf6a9876c394664d647355726290014b24efffc.tar.zst yuzu-faf6a9876c394664d647355726290014b24efffc.zip |
Diffstat (limited to 'src/audio_core/time_stretch.cpp')
-rw-r--r-- | src/audio_core/time_stretch.cpp | 68 |
1 files changed, 0 insertions, 68 deletions
diff --git a/src/audio_core/time_stretch.cpp b/src/audio_core/time_stretch.cpp deleted file mode 100644 index 726591fce..000000000 --- a/src/audio_core/time_stretch.cpp +++ /dev/null @@ -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 |