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update to a new version of STK reverb (inserting comb filters for more realistic reverberation effect)

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This commit is contained in:
Volker Fischer 2014-01-02 10:47:11 +00:00
parent 7da3489350
commit 2980c195a4
2 changed files with 39 additions and 4 deletions
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28
src/util.cpp
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@ -198,6 +198,7 @@ void CAudioReverb::Init ( const int iSampleRate,
for ( i = 0; i < 4; i++ )
{
combDelays[i].Init ( lengths[i] );
combFilters[i].setPole ( 0.2 );
}
setT60 ( rT60, iSampleRate );
@ -246,6 +247,10 @@ void CAudioReverb::Clear()
combDelays[1].Reset ( 0 );
combDelays[2].Reset ( 0 );
combDelays[3].Reset ( 0 );
combFilters[0].Reset();
combFilters[1].Reset();
combFilters[2].Reset();
combFilters[3].Reset();
outRightDelay.Reset ( 0 );
outLeftDelay.Reset ( 0 );
}
@ -261,6 +266,21 @@ void CAudioReverb::setT60 ( const double rT60,
}
}
void CAudioReverb::COnePole::setPole ( const double dPole )
{
// calculate IIR filter coefficients based on the pole value
dA = -dPole;
dB = 1.0 - dPole;
}
double CAudioReverb::COnePole::Calc ( const double dIn )
{
// calculate IIR filter
dLastSample = dB * dIn - dA * dLastSample;
return dLastSample;
}
void CAudioReverb::ProcessSample ( int16_t& iInputOutputLeft,
int16_t& iInputOutputRight,
const double dAttenuation )
@ -290,10 +310,10 @@ void CAudioReverb::ProcessSample ( int16_t& iInputOutputLeft,
allpassDelays[2].Add ( temp2 );
temp2 = - ( allpassCoefficient * temp2 ) + temp;
const double temp3 = temp2 + ( combCoefficient[0] * combDelays[0].Get() );
const double temp4 = temp2 + ( combCoefficient[1] * combDelays[1].Get() );
const double temp5 = temp2 + ( combCoefficient[2] * combDelays[2].Get() );
const double temp6 = temp2 + ( combCoefficient[3] * combDelays[3].Get() );
const double temp3 = temp2 + combFilters[0].Calc ( combCoefficient[0] * combDelays[0].Get() );
const double temp4 = temp2 + combFilters[1].Calc ( combCoefficient[1] * combDelays[1].Get() );
const double temp5 = temp2 + combFilters[2].Calc ( combCoefficient[2] * combDelays[2].Get() );
const double temp6 = temp2 + combFilters[3].Calc ( combCoefficient[3] * combDelays[3].Get() );
combDelays[0].Add ( temp3 );
combDelays[1].Add ( temp4 );

15
src/util.h
View file

@ -877,8 +877,23 @@ protected:
void setT60 ( const double rT60, const int iSampleRate );
bool isPrime ( const int number );
class COnePole
{
public:
COnePole() : dA ( 0 ), dB ( 0 ) { Reset(); }
void setPole ( const double dPole );
double Calc ( const double dIn );
void Reset() { dLastSample = 0; }
protected:
double dA;
double dB;
double dLastSample;
};
CFIFO<double> allpassDelays[3];
CFIFO<double> combDelays[4];
COnePole combFilters[4];
CFIFO<double> outLeftDelay;
CFIFO<double> outRightDelay;
double allpassCoefficient;