Signalsmith-Audio/basics
1
0
Fork 0
Code

Add detuning to reverb

Browse Source
This commit is contained in:
Geraint 2022-12-05 22:37:28 +00:00
parent 6e41b252a7
commit 713f3a309a
1 changed files with 86 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

111
reverb.h
View File

@ -20,21 +20,23 @@ namespace signalsmith { namespace basics {
using typename BaseEffect::ParamRange;
using typename BaseEffect::ParamSteps;
using Array = std::array<Sample, 8>;
using Array3 = std::array<Sample, 3>;
ParamRange dry{1}, wet{0.25};
ParamRange roomMs{100};
ParamRange rt20{3};
ParamRange dry{1}, wet{0.5};
ParamRange roomMs{80};
ParamRange rt20{1};
ParamRange early{1};
ParamRange detune{2};
ReverbSTFX(double maxRoomMs=200) : maxRoomMs(maxRoomMs) {}
ReverbSTFX(double maxRoomMs=200, double detuneDepthMs=2) : maxRoomMs(maxRoomMs), detuneDepthMs(detuneDepthMs) {}
template<class Storage>
void state(Storage &storage) {
using namespace signalsmith::units;
storage.info("[Basics] Reverb", "An FDN reverb");
int version = storage.version(3);
if (version != 3) return;
int version = storage.version(4);
if (version != 4) return;
storage.param("dry", dry)
.info("dry", "dry signal gain")
@ -59,14 +61,19 @@ namespace signalsmith { namespace basics {
storage.param("rt20", rt20)
.info("decay", "RT20: decay time to -20dB")
.range(0.1, 3, 30)
.range(0.01, 2, 30)
.unit("seconds", 2, 0, 1)
.unit("seconds", 1, 1, 1e100);
storage.param("early", early)
.info("early", "Early reflections")
.range(0, 1, 2)
.range(0, 1, 2.5)
.unit("%", 0, pcToRatio, ratioToPc);
storage.param("detune", detune)
.info("detune", "Detuning rate (inside feedback loop)")
.range(0, 5, 50)
.unit("", 1);
}
template<class Config>
@ -74,13 +81,15 @@ namespace signalsmith { namespace basics {
config.outputChannels = config.inputChannels = 2;
config.auxInputs.resize(0);
config.auxOutputs.resize(0);
detuneDepthSamples = detuneDepthMs*0.001*config.sampleRate;
double maxRoomSamples = maxRoomMs*0.001*config.sampleRate;
delay1.configure(maxRoomSamples, 0.125);
delay2.configure(maxRoomSamples, 1);
delay3.configure(maxRoomSamples, 0.5);
delay4.configure(maxRoomSamples, 0.25);
delayFeedback.configure(maxRoomSamples*2, 1);
delayFeedback.configure(maxRoomSamples*1.36 + detuneDepthSamples, 1);
delayEarly.configure(maxRoomSamples, 0.25);
}
@ -90,6 +99,8 @@ namespace signalsmith { namespace basics {
delay3.reset();
delayFeedback.reset();
delayEarly.reset();
detuneLfoPhase = 0;
}
int latencySamples() const {
@ -109,14 +120,14 @@ namespace signalsmith { namespace basics {
auto smoothedDryGain = block.smooth(dry);
Sample scalingFactor = stereoMixer.scalingFactor2()*0.015625; // 4 Hadamard mixes
auto smoothedWetGain = block.smooth(wet.from(), wet.to());
auto smoothedInputGain = block.smooth( // tuned by ear: smaller feedback loops with longer decays sound louder
scalingFactor*std::sqrt(roomMs.from()/(rt20.from()*50 + roomMs.from())),
scalingFactor*std::sqrt(roomMs.to()/(rt20.to()*50 + roomMs.to()))
);
using signalsmith::units::dbToGain;
auto smoothedDecayGain = block.smooth(
dbToGain(getDecayDb(rt20.from(), roomMs.from())),
dbToGain(getDecayDb(rt20.to(), roomMs.to()))
double decayGainFrom = dbToGain(getDecayDb(rt20.from(), roomMs.from()));
double decayGainTo = dbToGain(getDecayDb(rt20.to(), roomMs.to()));
auto smoothedDecayGain = block.smooth(decayGainFrom, decayGainTo);
auto smoothedInputGain = block.smooth( // scale according to the number of expected echoes in the first 100ms
scalingFactor*std::sqrt((1 - decayGainFrom)/(1 - std::pow(decayGainFrom, 100/roomMs.from()))),
scalingFactor*std::sqrt((1 - decayGainTo)/(1 - std::pow(decayGainTo, 100/roomMs.to())))
);
auto smoothedEarlyGain = block.smooth(early, [&](double g) {
return g*0.35; // tuned by ear
@ -126,15 +137,29 @@ namespace signalsmith { namespace basics {
updateDelays(roomMs.to()*0.001*config.sampleRate);
});
bool fading = block.fading();
// Detuning LFO rate
double detuneCentsPerLoop = detune*std::sqrt(roomMs*0.001);
double detuneLfoRate = (detuneCentsPerLoop*0.0004)/detuneDepthSamples; // tuned by ear, assuming 3/8 channels are detuned
for (int i = 0; i < block.length; ++i) {
Sample inputGain = smoothedInputGain.at(i);
Sample decayGain = smoothedDecayGain.at(i);
Sample earlyGain = smoothedEarlyGain.at(i);
std::array<Sample, 2> stereoIn = {inputLeft[i], inputRight[i]};
Array samples;
std::array<Sample, 2> stereoIn = {inputLeft[i]*inputGain, inputRight[i]*inputGain};
stereoMixer.stereoToMulti(stereoIn, samples);
std::array<Sample, 2> stereoInScaled = {stereoIn[0]*inputGain, stereoIn[1]*inputGain};
stereoMixer.stereoToMulti(stereoInScaled, samples);
double lfoCos = std::cos(detuneLfoPhase*2*M_PI), lfoSin = std::sin(detuneLfoPhase*2*M_PI);
Array3 lfoArray = {
(0.5 + lfoCos*0.5)*detuneDepthSamples,
(0.5 + lfoCos*-0.25 + lfoSin*0.43301270189)*detuneDepthSamples,
(0.5 + lfoCos*-0.25 + lfoSin*-0.43301270189)*detuneDepthSamples
};
detuneLfoPhase += detuneLfoRate;
if (fading) {
Sample fade = block.fade(i);
@ -143,10 +168,13 @@ namespace signalsmith { namespace basics {
samples = delay2.write(samples).read(fade);
Hadamard::unscaledInPlace(samples);
Array feedback = delayFeedback.read(fade);
Array feedback = delayFeedback.readDetuned(lfoArray, fade);
Householder::inPlace(feedback);
Array feedbackInput;
for (int c = 0; c < 8; ++c) feedbackInput[c] = samples[c] + feedback[c]*decayGain;
for (int c = 0; c < 8; ++c) {
int c2 = (c + 3)&7;
feedbackInput[c2] = samples[c] + feedback[c]*decayGain;
}
delayFeedback.write(feedbackInput);
Array earlyReflections = delayEarly.write(samples).read(fade);
@ -162,10 +190,13 @@ namespace signalsmith { namespace basics {
samples = delay2.write(samples).read();
Hadamard::unscaledInPlace(samples);
Array feedback = delayFeedback.read();
Array feedback = delayFeedback.readDetuned(lfoArray, lfoSin);
Householder::inPlace(feedback);
Array feedbackInput;
for (int c = 0; c < 8; ++c) feedbackInput[c] = samples[c] + feedback[c]*decayGain;
for (int c = 0; c < 8; ++c) {
int c2 = (c + 3)&7;
feedbackInput[c2] = samples[c] + feedback[c]*decayGain;
}
delayFeedback.write(feedbackInput);
Array earlyReflections = delayEarly.write(samples).read();
@ -185,11 +216,15 @@ namespace signalsmith { namespace basics {
outputLeft[i] = stereoIn[0]*dryGain + stereoOut[0]*wetGain;
outputRight[i] = stereoIn[1]*dryGain + stereoOut[1]*wetGain;
}
detuneLfoPhase -= std::floor(detuneLfoPhase);
}
private:
int channels = 0;
double maxRoomMs;
double maxRoomMs, detuneDepthMs;
double detuneLfoPhase = 0;
double detuneDepthSamples = 0;
static Sample getDecayDb(Sample rt20, Sample loopMs) {
Sample dbPerSecond = -20/rt20;
@ -236,7 +271,7 @@ namespace signalsmith { namespace basics {
rangeSamples *= delayScale;
delayOffsetsPrev = delayOffsets;
std::mt19937 engine(seed);
constexpr double ratios[8] = {0.125, -0.125, 0.375, -0.375, 0.625, -0.625, 0.875, -0.875};
constexpr double ratios[8] = {0.0625, -0.0625, 0.1875, -0.1875, 0.3125, -0.3125, 0.4375, -0.4375};
for (int i = 0; i < 8; ++i) {
delayOffsets[i] = int(-std::floor(rangeSamples*std::pow(2, ratios[i]/2)));
std::uniform_int_distribution<int> indexDist(0, i);
@ -269,6 +304,32 @@ namespace signalsmith { namespace basics {
}
return result;
}
signalsmith::delay::Reader<Sample, signalsmith::delay::InterpolatorLagrange7> fractionalReader;
Array readDetuned(Array3 lfoDepths) {
Array result;
for (int i = 0; i < 3; ++i) {
result[i] = fractionalReader.read(buffer[i], lfoDepths[i] - delayOffsets[i]);
}
for (int i = 3; i < 8; ++i) {
result[i] = buffer[i][delayOffsets[i]];
}
return result;
}
Array readDetuned(Array3 lfoDepths, Sample fade) {
Array result;
for (int i = 0; i < 3; ++i) {
Sample to = fractionalReader.read(buffer[i], lfoDepths[i] - delayOffsets[i]);
Sample from = fractionalReader.read(buffer[i], lfoDepths[i] - delayOffsetsPrev[i]);
result[i] = from + (to - from)*fade;
}
for (int i = 3; i < 8; ++i) {
Sample to = buffer[i][delayOffsets[i]];
Sample from = buffer[i][delayOffsetsPrev[i]];
result[i] = from + (to - from)*fade;
}
return result;
}
};
MultiDelay delay1, delay2, delay3, delay4, delayFeedback, delayEarly;