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/* ========================================
* PaulDither - PaulDither.h
* Copyright (c) 2016 airwindows, All rights reserved
* ======================================== */
#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;
long double inputSampleL;
long double inputSampleR;
while (--sampleFrames >= 0)
{
inputSampleL = *in1;
inputSampleR = *in2;
if (inputSampleL<1.2e-38 && -inputSampleL<1.2e-38) {
static int noisesource = 0;
//this declares a variable before anything else is compiled. It won't keep assigning
//it to 0 for every sample, it's as if the declaration doesn't exist in this context,
//but it lets me add this denormalization fix in a single place rather than updating
//it in three different locations. The variable isn't thread-safe but this is only
//a random seed and we can share it with whatever.
noisesource = noisesource % 1700021; noisesource++;
int residue = noisesource * noisesource;
residue = residue % 170003; residue *= residue;
residue = residue % 17011; residue *= residue;
residue = residue % 1709; residue *= residue;
residue = residue % 173; residue *= residue;
residue = residue % 17;
double applyresidue = residue;
applyresidue *= 0.00000001;
applyresidue *= 0.00000001;
inputSampleL = applyresidue;
}
if (inputSampleR<1.2e-38 && -inputSampleR<1.2e-38) {
static int noisesource = 0;
noisesource = noisesource % 1700021; noisesource++;
int residue = noisesource * noisesource;
residue = residue % 170003; residue *= residue;
residue = residue % 17011; residue *= residue;
residue = residue % 1709; residue *= residue;
residue = residue % 173; residue *= residue;
residue = residue % 17;
double applyresidue = residue;
applyresidue *= 0.00000001;
applyresidue *= 0.00000001;
inputSampleR = applyresidue;
//this denormalization routine produces a white noise at -300 dB which the noise
//shaping will interact with to produce a bipolar output, but the noise is actually
//all positive. That should stop any variables from going denormal, and the routine
//only kicks in if digital black is input. As a final touch, if you save to 24-bit
//the silence will return to being digital black again.
}
inputSampleL *= 8388608.0;
inputSampleR *= 8388608.0;
//0-1 is now one bit, now we dither
currentDitherL = (rand()/(double)RAND_MAX);
currentDitherR = (rand()/(double)RAND_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 /= 8388608.0;
inputSampleR /= 8388608.0;
*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;
long double inputSampleL;
long double inputSampleR;
while (--sampleFrames >= 0)
{
inputSampleL = *in1;
inputSampleR = *in2;
if (inputSampleL<1.2e-38 && -inputSampleL<1.2e-38) {
static int noisesource = 0;
//this declares a variable before anything else is compiled. It won't keep assigning
//it to 0 for every sample, it's as if the declaration doesn't exist in this context,
//but it lets me add this denormalization fix in a single place rather than updating
//it in three different locations. The variable isn't thread-safe but this is only
//a random seed and we can share it with whatever.
noisesource = noisesource % 1700021; noisesource++;
int residue = noisesource * noisesource;
residue = residue % 170003; residue *= residue;
residue = residue % 17011; residue *= residue;
residue = residue % 1709; residue *= residue;
residue = residue % 173; residue *= residue;
residue = residue % 17;
double applyresidue = residue;
applyresidue *= 0.00000001;
applyresidue *= 0.00000001;
inputSampleL = applyresidue;
}
if (inputSampleR<1.2e-38 && -inputSampleR<1.2e-38) {
static int noisesource = 0;
noisesource = noisesource % 1700021; noisesource++;
int residue = noisesource * noisesource;
residue = residue % 170003; residue *= residue;
residue = residue % 17011; residue *= residue;
residue = residue % 1709; residue *= residue;
residue = residue % 173; residue *= residue;
residue = residue % 17;
double applyresidue = residue;
applyresidue *= 0.00000001;
applyresidue *= 0.00000001;
inputSampleR = applyresidue;
//this denormalization routine produces a white noise at -300 dB which the noise
//shaping will interact with to produce a bipolar output, but the noise is actually
//all positive. That should stop any variables from going denormal, and the routine
//only kicks in if digital black is input. As a final touch, if you save to 24-bit
//the silence will return to being digital black again.
}
inputSampleL *= 8388608.0;
inputSampleR *= 8388608.0;
//0-1 is now one bit, now we dither
currentDitherL = (rand()/(double)RAND_MAX);
currentDitherR = (rand()/(double)RAND_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 /= 8388608.0;
inputSampleR /= 8388608.0;
*out1 = inputSampleL;
*out2 = inputSampleR;
*in1++;
*in2++;
*out1++;
*out2++;
}
}
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