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Diffstat (limited to 'src/mdaDither.cpp')
| -rw-r--r-- | src/mdaDither.cpp | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/src/mdaDither.cpp b/src/mdaDither.cpp new file mode 100644 index 0000000..85ecb83 --- /dev/null +++ b/src/mdaDither.cpp @@ -0,0 +1,261 @@ +#include "mdaDither.h" + +#include <math.h> +#include <stdlib.h> +#include <float.h> + +AudioEffect *createEffectInstance(audioMasterCallback audioMaster) +{ + return new mdaDither(audioMaster); +} + +mdaDither::mdaDither(audioMasterCallback audioMaster) : AudioEffectX(audioMaster, 1, 5) // programs, parameters +{ + //inits here! + fParam0 = 0.50f; //bits + fParam1 = 0.88f; //dither (off, rect, tri, hp-tri, hp-tri-2ndOrderShaped) + fParam2 = 0.50f; //dither level + fParam3 = 0.50f; //dc trim + fParam4 = 0.00f; //zoom (8 bit dither and fade audio out) + + sh1 = sh2 = sh3 = sh4 = 0.0f; + rnd1 = rnd3 = 0; + + setNumInputs(2); + setNumOutputs(2); + setUniqueID("mdad"); // identify here + DECLARE_LVZ_DEPRECATED(canMono) (); + canProcessReplacing(); + strcpy(programName, "Dither & Noise Shaping"); + + setParameter(0, 0.5f); +} + +bool mdaDither::getProductString(char* text) { strcpy(text, "mda Dither"); return true; } +bool mdaDither::getVendorString(char* text) { strcpy(text, "mda"); return true; } +bool mdaDither::getEffectName(char* name) { strcpy(name, "Dither"); return true; } + +void mdaDither::setParameter(LvzInt32 index, float value) +{ + switch(index) + { + case 0: fParam0 = value; break; + case 1: fParam1 = value; break; + case 2: fParam2 = value; break; + case 3: fParam3 = value; break; + case 4: fParam4 = value; break; + } + //calcs here + gain = 1.0f; + bits = 8.0f + 2.0f * (float)floor(8.9f * fParam0); + + if(fParam4>0.1f) //zoom to 6 bit & fade out audio + { + wlen = 32.0f; + gain = (1.0f - fParam4); gain*=gain; + } + else wlen = (float)pow(2.0f, bits - 1.0f); //word length in quanta + + //Using WaveLab 2.01 (unity gain) as a reference: + // 16-bit output is (int)floor(floating_point_value*32768.0f) + + offs = (4.0f * fParam3 - 1.5f) / wlen; //DC offset (plus 0.5 to round dither not truncate) + dith = 2.0f * fParam2 / (wlen * (float)32767); + shap=0.0f; + + switch((long)(fParam1*3.9)) //dither mode + { + case 0: dith = 0.0f; break; //off + case 3: shap = 0.5f; break; //noise shaping + default: break; //tri, hp-tri + } +} + +mdaDither::~mdaDither() +{ +} + +void mdaDither::suspend() +{ + //no need to zero buffers here as effect so small +} + +void mdaDither::setProgramName(char *name) +{ + strcpy(programName, name); +} + +void mdaDither::getProgramName(char *name) +{ + strcpy(name, programName); +} + +float mdaDither::getParameter(LvzInt32 index) +{ + float v=0; + + switch(index) + { + case 0: v = fParam0; break; + case 1: v = fParam1; break; + case 2: v = fParam2; break; + case 3: v = fParam3; break; + case 4: v = fParam4; break; + } + return v; +} + +void mdaDither::getParameterName(LvzInt32 index, char *label) +{ + switch(index) + { + case 0: strcpy(label, "Word Len"); break; + case 1: strcpy(label, "Dither "); break; + case 2: strcpy(label, "Dith Amp"); break; + case 3: strcpy(label, "DC Trim "); break; + case 4: strcpy(label, "Zoom... "); break; + } +} + +#include <stdio.h> +void long2string(long value, char *string) { sprintf(string, "%ld", value); } +void float2strng(float value, char *string) { sprintf(string, "%.2f", value); } + +void mdaDither::getParameterDisplay(LvzInt32 index, char *text) +{ + switch(index) + { + case 0: long2string((long)bits, text); break; + case 1: switch((long)(fParam1*3.9)) + { case 0: strcpy(text, "OFF"); break; + case 1: strcpy(text, "TRI"); break; + case 2: strcpy(text, "HP-TRI"); break; + default: strcpy(text, "N.SHAPE"); break; + } break; + case 2: float2strng(4.0f * fParam2, text); break; + case 3: float2strng(4.0f * fParam3 - 2.0f, text); break; + case 4: if(fParam4>0.1f) + if(gain<0.0001f) strcpy(text, "-80"); + else long2string((long)(20.0 * log10(gain)), text); + else strcpy(text, "OFF"); break; + } +} + +void mdaDither::getParameterLabel(LvzInt32 index, char *label) +{ + switch(index) + { + case 0: strcpy(label, "Bits"); break; + case 1: strcpy(label, ""); break; + case 2: strcpy(label, "lsb"); break; + case 3: strcpy(label, "lsb"); break; + case 4: strcpy(label, "dB"); break; + } +} + +//-------------------------------------------------------------------------------- +// process + +void mdaDither::process(float **inputs, float **outputs, LvzInt32 sampleFrames) +{ + float *in1 = inputs[0]; + float *in2 = inputs[1]; + float *out1 = outputs[0]; + float *out2 = outputs[1]; + float a, b, aa, bb, c, d; + float sl=shap, s1=sh1, s2=sh2, s3=sh3, s4=sh4; //shaping level, buffers + float dl=dith; //dither level + float o=offs, w=wlen, wi=1.0f/wlen; //DC offset, word length & inverse + float g=gain; //gain for Zoom mode + long r1=rnd1, r2, r3=rnd3, r4; //random numbers for dither + long m=1; //dither mode + if((long)(fParam1 * 3.9f)==1) m=0; //what is the fastest if(?) + + --in1; + --in2; + --out1; + --out2; + + while(--sampleFrames >= 0) + { + a = *++in1; + b = *++in2; + c = out1[1]; + d = out2[1]; + + r2=r1; r4=r3; + if(m==0) { r4=rand() & 0x7FFF; r2=(r4 & 0x7F)<<8; } + r1=rand() & 0x7FFF; r3=(r1 & 0x7F)<<8; + + a = g * a + sl * (s1 + s1 - s2); + aa = a + o + dl * (float)(r1 - r2); + if(aa<0.0f) aa-=wi; + aa = wi * (float)(long)(w * aa); + s2 = s1; + s1 = a - aa; + + b = g * b + sl * (s3 + s3 - s4); + bb = b + o + dl * (float)(r3 - r4); + if(bb<0.0f) bb-=wi; + bb = wi * (float)(long)(w * bb); + s4 = s3; + s3 = b - bb; + + *++out1 = c + aa; + *++out2 = d + bb; + } + + sh1=s1; sh2=s2; sh3=s3; sh4=s4; + rnd1=r1; rnd3=r3; +} + +void mdaDither::processReplacing(float **inputs, float **outputs, LvzInt32 sampleFrames) +{ + float *in1 = inputs[0]; + float *in2 = inputs[1]; + float *out1 = outputs[0]; + float *out2 = outputs[1]; + float a, b, aa, bb; + float sl=shap, s1=sh1, s2=sh2, s3=sh3, s4=sh4; //shaping level, buffers + float dl=dith; //dither level + float o=offs, w=wlen, wi=1.0f/wlen; //DC offset, word length & inverse + float g=gain; //gain for Zoom mode + long r1=rnd1, r2, r3=rnd3, r4; //random numbers for dither + long m=1; //dither mode + if((long)(fParam1 * 3.9f)==1) m=0; //what is the fastest if(?) + + --in1; + --in2; + --out1; + --out2; + + while(--sampleFrames >= 0) + { + a = *++in1; + b = *++in2; + + r2=r1; r4=r3; //HP-TRI dither (also used when noise shaping) + if(m==0) { r4=rand() & 0x7FFF; r2=(r4 & 0x7F)<<8; } //TRI dither + r1=rand() & 0x7FFF; r3=(r1 & 0x7F)<<8; //Assumes RAND_MAX=32767? + + a = g * a + sl * (s1 + s1 - s2); //target level + error feedback + aa = a + o + dl * (float)(r1 - r2); // + offset + dither + if(aa<0.0f) aa-=wi; //(long) truncates towards zero! + aa = wi * (float)(long)(w * aa); //truncate + s2 = s1; + s1 = a - aa; //error feedback: 2nd order noise shaping + + b = g * b + sl * (s3 + s3 - s4); + bb = b + o + dl * (float)(r3 - r4); + if(bb<0.0f) bb-=wi; + bb = wi * (float)(long)(w * bb); + s4 = s3; + s3 = b - bb; + + *++out1 = aa; + *++out2 = bb; + } + + sh1=s1; sh2=s2; sh3=s3; sh4=s4; //doesn't actually matter if these are + rnd1=r1; rnd3=r3; //saved or not as effect is so small ! +} |