From 9397fdfe95ad5f3e74a1fce2e049abddcbbbfba5 Mon Sep 17 00:00:00 2001 From: MerryMage Date: Wed, 12 Apr 2017 12:56:07 +0100 Subject: [PATCH] Mixer: Use a temporary buffer when stretching audio --- Source/Core/AudioCommon/Mixer.cpp | 48 ++++++++++++++----------------- Source/Core/AudioCommon/Mixer.h | 3 +- 2 files changed, 24 insertions(+), 27 deletions(-) diff --git a/Source/Core/AudioCommon/Mixer.cpp b/Source/Core/AudioCommon/Mixer.cpp index 0863dd1d7c..ffb9489246 100644 --- a/Source/Core/AudioCommon/Mixer.cpp +++ b/Source/Core/AudioCommon/Mixer.cpp @@ -132,20 +132,21 @@ unsigned int CMixer::Mix(short* samples, unsigned int num_samples) if (SConfig::GetInstance().m_audio_stretch) { - unsigned int actual_samples = std::min({ - m_dma_mixer.AvailableSamples(), m_streaming_mixer.AvailableSamples(), num_samples, - }); + unsigned int available_samples = + std::min(m_dma_mixer.AvailableSamples(), m_streaming_mixer.AvailableSamples()); - m_dma_mixer.Mix(samples, actual_samples, false); - m_streaming_mixer.Mix(samples, actual_samples, false); - m_wiimote_speaker_mixer.Mix(samples, actual_samples, false); + m_stretch_buffer.fill(0); + + m_dma_mixer.Mix(m_stretch_buffer.data(), available_samples, false); + m_streaming_mixer.Mix(m_stretch_buffer.data(), available_samples, false); + m_wiimote_speaker_mixer.Mix(m_stretch_buffer.data(), available_samples, false); if (!m_is_stretching) { m_sound_touch.clear(); m_is_stretching = true; } - StretchAudio(samples, actual_samples, num_samples); + StretchAudio(m_stretch_buffer.data(), available_samples, samples, num_samples); } else { @@ -158,12 +159,12 @@ unsigned int CMixer::Mix(short* samples, unsigned int num_samples) return num_samples; } -void CMixer::StretchAudio(short* samples, unsigned int actual_samples, unsigned int num_samples) +void CMixer::StretchAudio(const short* in, unsigned int num_in, short* out, unsigned int num_out) { - const double time_delta = static_cast(num_samples) / m_sampleRate; // seconds + const double time_delta = static_cast(num_out) / m_sampleRate; // seconds // We were given actual_samples number of samples, and num_samples were requested from us. - double current_ratio = static_cast(actual_samples) / static_cast(num_samples); + double current_ratio = static_cast(num_in) / static_cast(num_out); const double max_latency = SConfig::GetInstance().m_audio_stretch_max_latency; const double max_backlog = m_sampleRate * max_latency / 1000.0; @@ -171,7 +172,7 @@ void CMixer::StretchAudio(short* samples, unsigned int actual_samples, unsigned if (backlog_fullness > 1.0) { // Exceeded latency budget: Do not add more samples into FIFO. - actual_samples = 0; + num_in = 0; } // We ideally want the backlog to be about 50% full. @@ -182,7 +183,7 @@ void CMixer::StretchAudio(short* samples, unsigned int actual_samples, unsigned // 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 = 0.3; // seconds + constexpr double lpf_time_scale = 1.0; // seconds const double m_lpf_gain = 1.0 - std::exp(-time_delta / lpf_time_scale); m_stretch_ratio += m_lpf_gain * (current_ratio - m_stretch_ratio); @@ -190,29 +191,24 @@ void CMixer::StretchAudio(short* samples, unsigned int actual_samples, unsigned // many silence samples. These do not need to be timestretched. m_sound_touch.setTempo(std::max(m_stretch_ratio, 0.1)); - if (actual_samples != num_samples) - { - DEBUG_LOG(AUDIO, "Audio stretching: samples:%u/%u ratio:%f backlog:%f gain: %f", actual_samples, - num_samples, m_stretch_ratio, backlog_fullness, m_lpf_gain); - } + DEBUG_LOG(AUDIO, "Audio stretching: samples:%u/%u ratio:%f backlog:%f gain: %f", num_in, num_out, + m_stretch_ratio, backlog_fullness, m_lpf_gain); - m_sound_touch.putSamples(samples, actual_samples); + m_sound_touch.putSamples(in, num_in); - memset(samples, 0, num_samples * 2 * sizeof(short)); - - const size_t samples_received = m_sound_touch.receiveSamples(samples, num_samples); + const size_t samples_received = m_sound_touch.receiveSamples(out, num_out); if (samples_received != 0) { - m_last_stretched_sample[0] = samples[samples_received * 2 - 2]; - m_last_stretched_sample[1] = samples[samples_received * 2 - 1]; + m_last_stretched_sample[0] = out[samples_received * 2 - 2]; + m_last_stretched_sample[1] = out[samples_received * 2 - 1]; } // Preform padding if we've run out of samples. - for (size_t i = samples_received; i < num_samples; i++) + for (size_t i = samples_received; i < num_out; i++) { - samples[i * 2 + 0] = m_last_stretched_sample[0]; - samples[i * 2 + 1] = m_last_stretched_sample[1]; + out[i * 2 + 0] = m_last_stretched_sample[0]; + out[i * 2 + 1] = m_last_stretched_sample[1]; } } diff --git a/Source/Core/AudioCommon/Mixer.h b/Source/Core/AudioCommon/Mixer.h index 45b542bcf5..f2127cceba 100644 --- a/Source/Core/AudioCommon/Mixer.h +++ b/Source/Core/AudioCommon/Mixer.h @@ -75,7 +75,7 @@ private: u32 m_frac = 0; }; - void StretchAudio(short* samples, unsigned int actual_samples, unsigned int num_samples); + void StretchAudio(const short* in, unsigned int num_in, short* out, unsigned int num_out); MixerFifo m_dma_mixer{this, 32000}; MixerFifo m_streaming_mixer{this, 48000}; @@ -86,6 +86,7 @@ private: soundtouch::SoundTouch m_sound_touch; double m_stretch_ratio = 1.0; std::array m_last_stretched_sample = {}; + std::array m_stretch_buffer; WaveFileWriter m_wave_writer_dtk; WaveFileWriter m_wave_writer_dsp;