/* ======================================== * Slew - Slew.h * Created 8/12/11 by SPIAdmin * Copyright (c) 2011 __MyCompanyName__, All rights reserved * ======================================== */ #ifndef __Slew_H #include "Slew.h" #endif void Slew::processReplacing(float **inputs, float **outputs, VstInt32 sampleFrames) { float* in1 = inputs[0]; float* in2 = inputs[1]; float* out1 = outputs[0]; float* out2 = outputs[1]; double overallscale = 1.0; overallscale /= 44100.0; overallscale *= getSampleRate(); double inputSampleL; double inputSampleR; double outputSampleL; double outputSampleR; double clamp; double threshold = pow((1-gain),4)/overallscale; 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. } clamp = inputSampleL - lastSampleL; outputSampleL = inputSampleL; if (clamp > threshold) outputSampleL = lastSampleL + threshold; if (-clamp > threshold) outputSampleL = lastSampleL - threshold; lastSampleL = outputSampleL; clamp = inputSampleR - lastSampleR; outputSampleR = inputSampleR; if (clamp > threshold) outputSampleR = lastSampleR + threshold; if (-clamp > threshold) outputSampleR = lastSampleR - threshold; lastSampleR = outputSampleR; *out1 = outputSampleL; *out2 = outputSampleR; *in1++; *in2++; *out1++; *out2++; } } void Slew::processDoubleReplacing(double **inputs, double **outputs, VstInt32 sampleFrames) { double* in1 = inputs[0]; double* in2 = inputs[1]; double* out1 = outputs[0]; double* out2 = outputs[1]; double overallscale = 1.0; overallscale /= 44100.0; overallscale *= getSampleRate(); double inputSampleL; double inputSampleR; double outputSampleL; double outputSampleR; double clamp; double threshold = pow((1-gain),4)/overallscale; 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. } clamp = inputSampleL - lastSampleL; outputSampleL = inputSampleL; if (clamp > threshold) outputSampleL = lastSampleL + threshold; if (-clamp > threshold) outputSampleL = lastSampleL - threshold; lastSampleL = outputSampleL; clamp = inputSampleR - lastSampleR; outputSampleR = inputSampleR; if (clamp > threshold) outputSampleR = lastSampleR + threshold; if (-clamp > threshold) outputSampleR = lastSampleR - threshold; lastSampleR = outputSampleR; *out1 = outputSampleL; *out2 = outputSampleR; *in1++; *in2++; *out1++; *out2++; } }