Signalsmith-Audio/signalsmith-stretch
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Add reflected pre-roll to .outputSeek()

Browse Source
This commit is contained in:
Geraint 2025-08-11 16:37:44 +01:00
parent 2724daacaf
commit 90d6c686eb
2 changed files with 31 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
CMakeLists.txt
View File

@ -7,7 +7,7 @@ include(FetchContent)
FetchContent_Declare(
signalsmith-linear
GIT_REPOSITORY https://github.com/Signalsmith-Audio/linear.git
GIT_TAG 0.2.2
GIT_TAG 0.2.3
GIT_SHALLOW ON
)
FetchContent_MakeAvailable(signalsmith-linear)

55
signalsmith-stretch.h
View File

@ -89,7 +89,8 @@ struct SignalsmithStretch {
blockProcess = {};
formantMetric.resize(bands + 2);
tmpBuffer.resize(std::max(outputLatency()*channels, blockSamples + intervalSamples));
tmpProcessBuffer.resize(blockSamples + intervalSamples);
tmpPreRollBuffer.resize(outputLatency()*channels);
}
// For querying the existing config
int blockSamples() const {
@ -137,11 +138,11 @@ struct SignalsmithStretch {
// You should ideally feed it `seekLength()` frames of input, unless it's directly after a `.reset()` (in which case `.outputSeek()` might be a better choice)
template<class Inputs>
void seek(Inputs &&inputs, int inputSamples, double playbackRate) {
tmpBuffer.resize(0);
tmpBuffer.resize(stft.blockSamples() + stft.defaultInterval());
tmpProcessBuffer.resize(0);
tmpProcessBuffer.resize(stft.blockSamples() + stft.defaultInterval());
int startIndex = std::max<int>(0, inputSamples - int(tmpBuffer.size())); // start position in input
int padStart = int(tmpBuffer.size() + startIndex) - inputSamples; // start position in tmpBuffer
int startIndex = std::max<int>(0, inputSamples - int(tmpProcessBuffer.size())); // start position in input
int padStart = int(tmpProcessBuffer.size() + startIndex) - inputSamples; // start position in tmpProcessBuffer
Sample totalEnergy = 0;
for (int c = 0; c < channels; ++c) {
@ -149,12 +150,12 @@ struct SignalsmithStretch {
for (int i = startIndex; i < inputSamples; ++i) {
Sample s = inputChannel[i];
totalEnergy += s*s;
tmpBuffer[i - startIndex + padStart] = s;
tmpProcessBuffer[i - startIndex + padStart] = s;
}
stft.writeInput(c, tmpBuffer.size(), tmpBuffer.data());
stft.writeInput(c, tmpProcessBuffer.size(), tmpProcessBuffer.data());
}
stft.moveInput(tmpBuffer.size());
stft.moveInput(tmpProcessBuffer.size());
if (totalEnergy >= noiseFloor) {
silenceCounter = 0;
silenceFirst = true;
@ -180,20 +181,26 @@ struct SignalsmithStretch {
int seekSamples = inputLength - surplusInput;
seek(inputs, seekSamples, playbackRate);
tmpBuffer.resize(outputLatency()*channels);
struct PreRollOutput {
tmpPreRollBuffer.resize(outputLatency()*channels);
struct BufferOutput {
Sample *samples;
int length;
Sample * operator[](int c) {
return samples + c*length;
}
} preRollOutput{tmpBuffer.data(), outputLatency()};
} preRollOutput{tmpPreRollBuffer.data(), outputLatency()};
// Use the surplus input to produce pre-roll output
OffsetIO<Inputs> offsetInput{inputs, seekSamples};
process(offsetInput, surplusInput, preRollOutput, outputLatency());
// TODO: put the thing down, flip it and reverse it
process(offsetInput, surplusInput, preRollOutput, preRollOutput.length);
// put the thing down, flip it and reverse it
for (auto &v : tmpPreRollBuffer) v = -v;
for (int c = 0; c < channels; ++c) {
std::reverse(preRollOutput[c], preRollOutput[c] + preRollOutput.length);
stft.addOutput(c, preRollOutput.length, preRollOutput[c]);
}
}
int outputSeekLength(Sample playbackRate) const {
return inputLatency() + playbackRate*outputLatency();
@ -208,14 +215,14 @@ struct SignalsmithStretch {
auto copyInput = [&](int toIndex){
int length = std::min<int>(int(stft.blockSamples() + stft.defaultInterval()), toIndex - prevCopiedInput);
tmpBuffer.resize(length);
tmpProcessBuffer.resize(length);
int offset = toIndex - length;
for (int c = 0; c < channels; ++c) {
auto &&inputBuffer = inputs[c];
for (int i = 0; i < length; ++i) {
tmpBuffer[i] = inputBuffer[i + offset];
tmpProcessBuffer[i] = inputBuffer[i + offset];
}
stft.writeInput(c, length, tmpBuffer.data());
stft.writeInput(c, length, tmpProcessBuffer.data());
}
stft.moveInput(length);
prevCopiedInput = toIndex;
@ -433,19 +440,17 @@ struct SignalsmithStretch {
if (outputBlock > 0) process(zeros, outputBlock*playbackRate, outputs, outputBlock);
int tailSamples = outputSamples - outputBlock; // at most one interval
int reflectSamples = std::min<int>(tailSamples, outputSamples - tailSamples);
tmpProcessBuffer.resize(tailSamples);
stft.finishOutput(1);
for (int c = 0; c < channels; ++c) {
tmpBuffer.resize(tailSamples);
stft.readOutput(c, tailSamples, tmpBuffer.data());
stft.readOutput(c, tailSamples, tmpProcessBuffer.data());
auto &&outputChannel = outputs[c];
for (int i = 0; i < tailSamples; ++i) {
outputChannel[outputBlock + i] = tmpBuffer[i];
outputChannel[outputBlock + i] = tmpProcessBuffer[i];
}
tmpBuffer.resize(reflectSamples);
stft.readOutput(c, reflectSamples, tailSamples, tmpBuffer.data());
for (int i = 0; i < reflectSamples; ++i) {
outputChannel[outputBlock + tailSamples - 1 - i] -= tmpBuffer[i];
stft.readOutput(c, tailSamples, tailSamples, tmpProcessBuffer.data());
for (int i = 0; i < tailSamples; ++i) {
outputChannel[outputBlock + tailSamples - 1 - i] -= tmpProcessBuffer[i];
}
}
stft.reset(0.1f);
@ -516,7 +521,7 @@ private:
typename STFT::Input stashedInput;
typename STFT::Output stashedOutput;
std::vector<Sample> tmpBuffer;
std::vector<Sample> tmpProcessBuffer, tmpPreRollBuffer;
int channels = 0, bands = 0;
int prevInputOffset = -1;