mirror of
https://github.com/cookiengineer/audacity
synced 2025-07-28 14:39:28 +02:00
126 lines
3.4 KiB
C++
126 lines
3.4 KiB
C++
/***************************************************/
|
|
/*! \class JCRev
|
|
\brief John Chowning's reverberator class.
|
|
|
|
This class is derived from the CLM JCRev
|
|
function, which is based on the use of
|
|
networks of simple allpass and comb delay
|
|
filters. This class implements three series
|
|
allpass units, followed by four parallel comb
|
|
filters, and two decorrelation delay lines in
|
|
parallel at the output.
|
|
|
|
by Perry R. Cook and Gary P. Scavone, 1995 - 2005.
|
|
*/
|
|
/***************************************************/
|
|
|
|
#include "JCRev.h"
|
|
#include <math.h>
|
|
|
|
using namespace Nyq;
|
|
|
|
JCRev :: JCRev(StkFloat T60)
|
|
{
|
|
// Delay lengths for 44100 Hz sample rate.
|
|
int lengths[9] = {1777, 1847, 1993, 2137, 389, 127, 43, 211, 179};
|
|
double scaler = Stk::sampleRate() / 44100.0;
|
|
|
|
int delay, i;
|
|
if ( scaler != 1.0 ) {
|
|
for (i=0; i<9; i++) {
|
|
delay = (int) floor(scaler * lengths[i]);
|
|
if ( (delay & 1) == 0) delay++;
|
|
while ( !this->isPrime(delay) ) delay += 2;
|
|
lengths[i] = delay;
|
|
}
|
|
}
|
|
|
|
for (i=0; i<3; i++) {
|
|
allpassDelays_[i].setMaximumDelay( lengths[i+4] );
|
|
allpassDelays_[i].setDelay( lengths[i+4] );
|
|
}
|
|
|
|
for ( i=0; i<4; i++ ) {
|
|
combDelays_[i].setMaximumDelay( lengths[i] );
|
|
combDelays_[i].setDelay( lengths[i] );
|
|
}
|
|
|
|
this->setT60( T60 );
|
|
outLeftDelay_.setMaximumDelay( lengths[7] );
|
|
outLeftDelay_.setDelay( lengths[7] );
|
|
outRightDelay_.setMaximumDelay( lengths[8] );
|
|
outRightDelay_.setDelay( lengths[8] );
|
|
allpassCoefficient_ = 0.7;
|
|
effectMix_ = 0.3;
|
|
this->clear();
|
|
}
|
|
|
|
JCRev :: ~JCRev()
|
|
{
|
|
}
|
|
|
|
void JCRev :: clear()
|
|
{
|
|
allpassDelays_[0].clear();
|
|
allpassDelays_[1].clear();
|
|
allpassDelays_[2].clear();
|
|
combDelays_[0].clear();
|
|
combDelays_[1].clear();
|
|
combDelays_[2].clear();
|
|
combDelays_[3].clear();
|
|
outRightDelay_.clear();
|
|
outLeftDelay_.clear();
|
|
lastOutput_[0] = 0.0;
|
|
lastOutput_[1] = 0.0;
|
|
}
|
|
|
|
void JCRev :: setT60( StkFloat T60 )
|
|
{
|
|
for ( int i=0; i<4; i++ )
|
|
combCoefficient_[i] = pow(10.0, (-3.0 * combDelays_[i].getDelay() / (T60 * Stk::sampleRate())));
|
|
}
|
|
|
|
StkFloat JCRev :: computeSample(StkFloat input)
|
|
{
|
|
StkFloat temp, temp0, temp1, temp2, temp3, temp4, temp5, temp6;
|
|
StkFloat filtout;
|
|
|
|
temp = allpassDelays_[0].lastOut();
|
|
temp0 = allpassCoefficient_ * temp;
|
|
temp0 += input;
|
|
allpassDelays_[0].tick(temp0);
|
|
temp0 = -(allpassCoefficient_ * temp0) + temp;
|
|
|
|
temp = allpassDelays_[1].lastOut();
|
|
temp1 = allpassCoefficient_ * temp;
|
|
temp1 += temp0;
|
|
allpassDelays_[1].tick(temp1);
|
|
temp1 = -(allpassCoefficient_ * temp1) + temp;
|
|
|
|
temp = allpassDelays_[2].lastOut();
|
|
temp2 = allpassCoefficient_ * temp;
|
|
temp2 += temp1;
|
|
allpassDelays_[2].tick(temp2);
|
|
temp2 = -(allpassCoefficient_ * temp2) + temp;
|
|
|
|
temp3 = temp2 + (combCoefficient_[0] * combDelays_[0].lastOut());
|
|
temp4 = temp2 + (combCoefficient_[1] * combDelays_[1].lastOut());
|
|
temp5 = temp2 + (combCoefficient_[2] * combDelays_[2].lastOut());
|
|
temp6 = temp2 + (combCoefficient_[3] * combDelays_[3].lastOut());
|
|
|
|
combDelays_[0].tick(temp3);
|
|
combDelays_[1].tick(temp4);
|
|
combDelays_[2].tick(temp5);
|
|
combDelays_[3].tick(temp6);
|
|
|
|
filtout = temp3 + temp4 + temp5 + temp6;
|
|
|
|
lastOutput_[0] = effectMix_ * (outLeftDelay_.tick(filtout));
|
|
lastOutput_[1] = effectMix_ * (outRightDelay_.tick(filtout));
|
|
temp = (1.0 - effectMix_) * input;
|
|
lastOutput_[0] += temp;
|
|
lastOutput_[1] += temp;
|
|
|
|
return Effect::lastOut();
|
|
}
|