airwindows/plugins/MacSignedVST/PaulDither/source/PaulDitherProc.cpp
2022-11-21 09:20:21 -05:00

152 lines
No EOL
4.4 KiB
C++
Executable file

/* ========================================
* PaulDither - PaulDither.h
* Copyright (c) 2016 airwindows, Airwindows uses the MIT license
* ======================================== */
#ifndef __PaulDither_H
#include "PaulDither.h"
#endif
void PaulDither::processReplacing(float **inputs, float **outputs, VstInt32 sampleFrames)
{
float* in1 = inputs[0];
float* in2 = inputs[1];
float* out1 = outputs[0];
float* out2 = outputs[1];
double currentDitherL;
double currentDitherR;
int processing = (VstInt32)( A * 1.999 );
bool highres = false;
if (processing == 1) highres = true;
float scaleFactor;
if (highres) scaleFactor = 8388608.0;
else scaleFactor = 32768.0;
float derez = B;
if (derez > 0.0) scaleFactor *= pow(1.0-derez,6);
if (scaleFactor < 0.0001) scaleFactor = 0.0001;
float outScale = scaleFactor;
if (outScale < 8.0) outScale = 8.0;
while (--sampleFrames >= 0)
{
double inputSampleL = *in1;
double inputSampleR = *in2;
if (fabs(inputSampleL)<1.18e-23) inputSampleL = fpdL * 1.18e-17;
fpdL ^= fpdL << 13; fpdL ^= fpdL >> 17; fpdL ^= fpdL << 5;
if (fabs(inputSampleR)<1.18e-23) inputSampleR = fpdR * 1.18e-17;
fpdR ^= fpdR << 13; fpdR ^= fpdR >> 17; fpdR ^= fpdR << 5;
inputSampleL *= scaleFactor;
inputSampleR *= scaleFactor;
//0-1 is now one bit, now we dither
currentDitherL = (double(fpdL)/UINT32_MAX);
currentDitherR = (double(fpdR)/UINT32_MAX);
inputSampleL += currentDitherL;
inputSampleR += currentDitherR;
inputSampleL -= previousDitherL;
inputSampleR -= previousDitherR;
inputSampleL = floor(inputSampleL);
inputSampleR = floor(inputSampleR);
previousDitherL = currentDitherL;
previousDitherR = currentDitherR;
//Paul Frindle: It's true that the dither itself can sound different
//if it's given a different freq response and you get to hear it.
//The one we use most is triangular single pole high pass dither.
//It not freq bent enough sound odd, but is slightly less audible than
//flat dither. It can also be easily made by taking one sample of dither
//away from the previous one - this gives you the triangular PDF and the
//filtering in one go :-)
inputSampleL /= outScale;
inputSampleR /= outScale;
*out1 = inputSampleL;
*out2 = inputSampleR;
*in1++;
*in2++;
*out1++;
*out2++;
}
}
void PaulDither::processDoubleReplacing(double **inputs, double **outputs, VstInt32 sampleFrames)
{
double* in1 = inputs[0];
double* in2 = inputs[1];
double* out1 = outputs[0];
double* out2 = outputs[1];
double currentDitherL;
double currentDitherR;
int processing = (VstInt32)( A * 1.999 );
bool highres = false;
if (processing == 1) highres = true;
float scaleFactor;
if (highres) scaleFactor = 8388608.0;
else scaleFactor = 32768.0;
float derez = B;
if (derez > 0.0) scaleFactor *= pow(1.0-derez,6);
if (scaleFactor < 0.0001) scaleFactor = 0.0001;
float outScale = scaleFactor;
if (outScale < 8.0) outScale = 8.0;
while (--sampleFrames >= 0)
{
double inputSampleL = *in1;
double inputSampleR = *in2;
if (fabs(inputSampleL)<1.18e-23) inputSampleL = fpdL * 1.18e-17;
fpdL ^= fpdL << 13; fpdL ^= fpdL >> 17; fpdL ^= fpdL << 5;
if (fabs(inputSampleR)<1.18e-23) inputSampleR = fpdR * 1.18e-17;
fpdR ^= fpdR << 13; fpdR ^= fpdR >> 17; fpdR ^= fpdR << 5;
inputSampleL *= scaleFactor;
inputSampleR *= scaleFactor;
//0-1 is now one bit, now we dither
currentDitherL = (double(fpdL)/UINT32_MAX);
currentDitherR = (double(fpdR)/UINT32_MAX);
inputSampleL += currentDitherL;
inputSampleR += currentDitherR;
inputSampleL -= previousDitherL;
inputSampleR -= previousDitherR;
inputSampleL = floor(inputSampleL);
inputSampleR = floor(inputSampleR);
previousDitherL = currentDitherL;
previousDitherR = currentDitherR;
//Paul Frindle: It's true that the dither itself can sound different
//if it's given a different freq response and you get to hear it.
//The one we use most is triangular single pole high pass dither.
//It not freq bent enough sound odd, but is slightly less audible than
//flat dither. It can also be easily made by taking one sample of dither
//away from the previous one - this gives you the triangular PDF and the
//filtering in one go :-)
inputSampleL /= outScale;
inputSampleR /= outScale;
*out1 = inputSampleL;
*out2 = inputSampleR;
*in1++;
*in2++;
*out1++;
*out2++;
}
}