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/* ========================================
* TapeDither - TapeDither.h
* Copyright (c) 2016 airwindows, All rights reserved
* ======================================== */
#ifndef __TapeDither_H
#include "TapeDither.h"
#endif
void TapeDither::processReplacing(float **inputs, float **outputs, VstInt32 sampleFrames)
{
float* in1 = inputs[0];
float* in2 = inputs[1];
float* out1 = outputs[0];
float* out2 = outputs[1];
long double inputSampleL;
long double inputSampleR;
double currentDitherL;
double currentDitherR;
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 -= previousDither4L;
inputSampleR -= previousDither4R;
inputSampleL = floor(inputSampleL);
inputSampleR = floor(inputSampleR);
previousDither4L = previousDither3L;
previousDither3L = previousDither2L;
previousDither2L = previousDither1L;
previousDither1L = currentDitherL;
previousDither4R = previousDither3R;
previousDither3R = previousDither2R;
previousDither2R = previousDither1R;
previousDither1R = currentDitherR;
inputSampleL /= 8388608.0;
inputSampleR /= 8388608.0;
*out1 = inputSampleL;
*out2 = inputSampleR;
*in1++;
*in2++;
*out1++;
*out2++;
}
}
void TapeDither::processDoubleReplacing(double **inputs, double **outputs, VstInt32 sampleFrames)
{
double* in1 = inputs[0];
double* in2 = inputs[1];
double* out1 = outputs[0];
double* out2 = outputs[1];
long double inputSampleL;
long double inputSampleR;
double currentDitherL;
double currentDitherR;
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 -= previousDither4L;
inputSampleR -= previousDither4R;
inputSampleL = floor(inputSampleL);
inputSampleR = floor(inputSampleR);
previousDither4L = previousDither3L;
previousDither3L = previousDither2L;
previousDither2L = previousDither1L;
previousDither1L = currentDitherL;
previousDither4R = previousDither3R;
previousDither3R = previousDither2R;
previousDither2R = previousDither1R;
previousDither1R = currentDitherR;
inputSampleL /= 8388608.0;
inputSampleR /= 8388608.0;
*out1 = inputSampleL;
*out2 = inputSampleR;
*in1++;
*in2++;
*out1++;
*out2++;
}
}
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