ref: 1fdec38ec4c2fe00804f80c23583fb1f14728f78
dir: /LEAF/Src/leaf-analysis.c/
/*==============================================================================
leaf-analysis.c
Created: 30 Nov 2018 11:56:49am
Author: airship
==============================================================================*/
#if _WIN32 || _WIN64
#include "..\Inc\leaf-analysis.h"
#include "..\Externals\d_fft_mayer.h"
#else
#include "../Inc/leaf-analysis.h"
#include "../Externals/d_fft_mayer.h"
#endif
//===========================================================================
/* Envelope Follower */
//===========================================================================
void tEnvelopeFollower_init(tEnvelopeFollower* const e, float attackThreshold, float decayCoeff)
{
e->y = 0.0f;
e->a_thresh = attackThreshold;
e->d_coeff = decayCoeff;
}
void tEnvelopeFollower_free(tEnvelopeFollower* const e)
{
}
float tEnvelopeFollower_tick(tEnvelopeFollower* const ef, float x)
{
if (x < 0.0f ) x = -x; /* Absolute value. */
if ((x >= ef->y) && (x > ef->a_thresh)) ef->y = x; /* If we hit a peak, ride the peak to the top. */
else ef->y = ef->y * ef->d_coeff; /* Else, exponential decay of output. */
//ef->y = envelope_pow[(uint16_t)(ef->y * (float)UINT16_MAX)] * ef->d_coeff; //not quite the right behavior - too much loss of precision?
//ef->y = powf(ef->y, 1.000009f) * ef->d_coeff; // too expensive
if( ef->y < VSF) ef->y = 0.0f;
return ef->y;
}
int tEnvelopeFollower_decayCoeff(tEnvelopeFollower* const ef, float decayCoeff)
{
return ef->d_coeff = decayCoeff;
}
int tEnvelopeFollower_attackThresh(tEnvelopeFollower* const ef, float attackThresh)
{
return ef->a_thresh = attackThresh;
}
//===========================================================================
/* Power Follower */
//===========================================================================
void tPowerFollower_init(tPowerFollower* const p, float factor)
{
p->curr=0.0f;
p->factor=factor;
p->oneminusfactor=1.0f-factor;
}
void tPowerFollower_free(tPowerFollower* const p)
{
}
int tPowerFollower_setFactor(tPowerFollower* const p, float factor)
{
if (factor<0) factor=0;
if (factor>1) factor=1;
p->factor=factor;
p->oneminusfactor=1.0f-factor;
return 0;
}
float tPowerFollower_tick(tPowerFollower* const p, float input)
{
p->curr = p->factor*input*input+p->oneminusfactor*p->curr;
return p->curr;
}
float tPowerFollower_sample(tPowerFollower* const p)
{
return p->curr;
}
//===========================================================================
/* ---------------- env~ - simple envelope follower. ----------------- */
//===========================================================================
void tEnvPD_init(tEnvPD* const x, int ws, int hs, int bs)
{
int period = hs, npoints = ws;
int i;
if (npoints < 1) npoints = 1024;
if (period < 1) period = npoints/2;
if (period < npoints / MAXOVERLAP + 1)
period = npoints / MAXOVERLAP + 1;
x->x_npoints = npoints;
x->x_phase = 0;
x->x_period = period;
x->windowSize = npoints;
x->hopSize = period;
x->blockSize = bs;
for (i = 0; i < MAXOVERLAP; i++) x->x_sumbuf[i] = 0;
for (i = 0; i < npoints; i++)
x->buf[i] = (1.0f - cosf((2 * PI * i) / npoints))/npoints;
for (; i < npoints+INITVSTAKEN; i++) x->buf[i] = 0;
x->x_f = 0;
x->x_allocforvs = INITVSTAKEN;
// ~ ~ ~ dsp ~ ~ ~
if (x->x_period % x->blockSize)
{
x->x_realperiod = x->x_period + x->blockSize - (x->x_period % x->blockSize);
}
else
{
x->x_realperiod = x->x_period;
}
// ~ ~ ~ ~ ~ ~ ~ ~
}
void tEnvPD_free (tEnvPD* const x)
{
}
float tEnvPD_tick (tEnvPD* const x)
{
return powtodb(x->x_result);
}
void tEnvPD_processBlock(tEnvPD* const x, float* in)
{
int n = x->blockSize;
int count;
t_sample *sump;
in += n;
for (count = x->x_phase, sump = x->x_sumbuf;
count < x->x_npoints; count += x->x_realperiod, sump++)
{
t_sample *hp = x->buf + count;
t_sample *fp = in;
t_sample sum = *sump;
int i;
for (i = 0; i < n; i++)
{
fp--;
sum += *hp++ * (*fp * *fp);
}
*sump = sum;
}
sump[0] = 0;
x->x_phase -= n;
if (x->x_phase < 0)
{
x->x_result = x->x_sumbuf[0];
for (count = x->x_realperiod, sump = x->x_sumbuf;
count < x->x_npoints; count += x->x_realperiod, sump++)
sump[0] = sump[1];
sump[0] = 0;
x->x_phase = x->x_realperiod - n;
}
}
//===========================================================================
// ATTACKDETECTION
//===========================================================================
/********Private function prototypes**********/
static void atkdtk_init(tAttackDetection* const a, int blocksize, int atk, int rel);
static void atkdtk_envelope(tAttackDetection* const a, float *in);
/********Constructor/Destructor***************/
void tAttackDetection_init(tAttackDetection* const a, int blocksize)
{
atkdtk_init(a, blocksize, DEFATTACK, DEFRELEASE);
}
void tAttackDetection_init_expanded(tAttackDetection* const a, int blocksize, int atk, int rel)
{
atkdtk_init(a, blocksize, atk, rel);
}
void tAttackDetection_free(tAttackDetection *a)
{
}
/*******Public Functions***********/
void tAttackDetection_setBlocksize(tAttackDetection* const a, int size)
{
if(!((size==64)|(size==128)|(size==256)|(size==512)|(size==1024)|(size==2048)))
size = DEFBLOCKSIZE;
a->blocksize = size;
return;
}
void tAttackDetection_setSamplerate(tAttackDetection* const a, int inRate)
{
a->samplerate = inRate;
//Reset atk and rel to recalculate coeff
tAttackDetection_setAtk(a, a->atk);
tAttackDetection_setRel(a, a->rel);
return;
}
void tAttackDetection_setThreshold(tAttackDetection* const a, float thres)
{
a->threshold = thres;
return;
}
void tAttackDetection_setAtk(tAttackDetection* const a, int inAtk)
{
a->atk = inAtk;
a->atk_coeff = pow(0.01, 1.0/(a->atk * a->samplerate * 0.001));
return;
}
void tAttackDetection_setRel(tAttackDetection* const a, int inRel)
{
a->rel = inRel;
a->rel_coeff = pow(0.01, 1.0/(a->rel * a->samplerate * 0.001));
return;
}
int tAttackDetection_detect(tAttackDetection* const a, float *in)
{
int result;
atkdtk_envelope(a, in);
if(a->env >= a->prevAmp*2) //2 times greater = 6dB increase
result = 1;
else
result = 0;
a->prevAmp = a->env;
return result;
}
/*******Private Functions**********/
static void atkdtk_init(tAttackDetection* const a, int blocksize, int atk, int rel)
{
a->env = 0;
a->blocksize = blocksize;
a->threshold = DEFTHRESHOLD;
a->samplerate = leaf.sampleRate;
a->prevAmp = 0;
a->env = 0;
tAttackDetection_setAtk(a, atk);
tAttackDetection_setRel(a, rel);
}
static void atkdtk_envelope(tAttackDetection* const a, float *in)
{
int i = 0;
float tmp;
for(i = 0; i < a->blocksize; ++i){
tmp = fastabs(in[i]);
if(tmp > a->env)
a->env = a->atk_coeff * (a->env - tmp) + tmp;
else
a->env = a->rel_coeff * (a->env - tmp) + tmp;
}
}
//===========================================================================
// PERIODDETECTION
//===========================================================================
void tPeriodDetection_init (tPeriodDetection* const p, float* in, float* out, int bufSize, int frameSize)
{
p->inBuffer = in;
p->outBuffer = out;
p->bufSize = bufSize;
p->frameSize = frameSize;
p->framesPerBuffer = p->bufSize / p->frameSize;
p->curBlock = 1;
p->lastBlock = 0;
p->index = 0;
p->hopSize = DEFHOPSIZE;
p->windowSize = DEFWINDOWSIZE;
p->fba = FBA;
tEnvPD_init(&p->env, p->windowSize, p->hopSize, p->frameSize);
tSNAC_init(&p->snac, DEFOVERLAP);
p->timeConstant = DEFTIMECONSTANT;
p->radius = expf(-1000.0f * p->hopSize * leaf.invSampleRate / p->timeConstant);
}
void tPeriodDetection_free (tPeriodDetection* const p)
{
tEnvPD_free(&p->env);
tSNAC_free(&p->snac);
}
float tPeriodDetection_findPeriod (tPeriodDetection* p, float sample)
{
int i, iLast;
i = (p->curBlock*p->frameSize);
iLast = (p->lastBlock*p->frameSize)+p->index;
p->i = i;
p->iLast = iLast;
p->inBuffer[i+p->index] = sample;
p->index++;
p->indexstore = p->index;
if (p->index >= p->frameSize)
{
p->index = 0;
tEnvPD_processBlock(&p->env, &(p->inBuffer[i]));
tSNAC_ioSamples(&p->snac, &(p->inBuffer[i]), &(p->outBuffer[i]), p->frameSize);
p->period = tSNAC_getPeriod(&p->snac);
p->curBlock++;
if (p->curBlock >= p->framesPerBuffer) p->curBlock = 0;
p->lastBlock++;
if (p->lastBlock >= p->framesPerBuffer) p->lastBlock = 0;
}
// changed from period to p->period
return p->period;
}
void tPeriodDetection_setHopSize(tPeriodDetection* p, int hs)
{
p->hopSize = hs;
}
void tPeriodDetection_setWindowSize(tPeriodDetection* p, int ws)
{
p->windowSize = ws;
}
//===========================================================================
// SNAC
//===========================================================================
/******************************************************************************/
/***************************** private procedures *****************************/
/******************************************************************************/
#define REALFFT mayer_realfft
#define REALIFFT mayer_realifft
static void snac_analyzeframe(tSNAC* const s);
static void snac_autocorrelation(tSNAC* const s);
static void snac_normalize(tSNAC* const s);
static void snac_pickpeak(tSNAC* const s);
static void snac_periodandfidelity(tSNAC* const s);
static void snac_biasbuf(tSNAC* const s);
static float snac_spectralpeak(tSNAC* const s, float periodlength);
/******************************************************************************/
/******************************** constructor, destructor *********************/
/******************************************************************************/
void tSNAC_init(tSNAC* const s, int overlaparg)
{
s->biasfactor = DEFBIAS;
s->timeindex = 0;
s->periodindex = 0;
s->periodlength = 0.;
s->fidelity = 0.;
s->minrms = DEFMINRMS;
s->framesize = SNAC_FRAME_SIZE;
s->inputbuf = (float*) leaf_alloc(sizeof(float) * SNAC_FRAME_SIZE);
s->processbuf = (float*) leaf_alloc(sizeof(float) * (SNAC_FRAME_SIZE * 2));
s->spectrumbuf = (float*) leaf_alloc(sizeof(float) * (SNAC_FRAME_SIZE / 2));
s->biasbuf = (float*) leaf_alloc(sizeof(float) * SNAC_FRAME_SIZE);
snac_biasbuf(s);
tSNAC_setOverlap(s, overlaparg);
}
void tSNAC_free(tSNAC* const s)
{
leaf_free(s->inputbuf);
leaf_free(s->processbuf);
leaf_free(s->spectrumbuf);
leaf_free(s->biasbuf);
}
/******************************************************************************/
/************************** public access functions****************************/
/******************************************************************************/
void tSNAC_ioSamples(tSNAC* const s, float *in, float *out, int size)
{
int timeindex = s->timeindex;
int mask = s->framesize - 1;
int outindex = 0;
float *inputbuf = s->inputbuf;
float *processbuf = s->processbuf;
// call analysis function when it is time
if(!(timeindex & (s->framesize / s->overlap - 1))) snac_analyzeframe(s);
while(size--)
{
inputbuf[timeindex] = *in++;
out[outindex++] = processbuf[timeindex++];
timeindex &= mask;
}
s->timeindex = timeindex;
}
void tSNAC_setOverlap(tSNAC* const s, int lap)
{
if(!((lap==1)|(lap==2)|(lap==4)|(lap==8))) lap = DEFOVERLAP;
s->overlap = lap;
}
void tSNAC_setBias(tSNAC* const s, float bias)
{
if(bias > 1.) bias = 1.;
if(bias < 0.) bias = 0.;
s->biasfactor = bias;
snac_biasbuf(s);
return;
}
void tSNAC_setMinRMS(tSNAC* const s, float rms)
{
if(rms > 1.) rms = 1.;
if(rms < 0.) rms = 0.;
s->minrms = rms;
return;
}
float tSNAC_getPeriod(tSNAC* const s)
{
return(s->periodlength);
}
float tSNAC_getFidelity(tSNAC* const s)
{
return(s->fidelity);
}
/******************************************************************************/
/***************************** private procedures *****************************/
/******************************************************************************/
// main analysis function
static void snac_analyzeframe(tSNAC* const s)
{
int n, tindex = s->timeindex;
int framesize = s->framesize;
int mask = framesize - 1;
float norm = 1. / sqrt((float)(framesize * 2));
float *inputbuf = s->inputbuf;
float *processbuf = s->processbuf;
// copy input to processing buffers
for(n=0; n<framesize; n++)
{
processbuf[n] = inputbuf[tindex] * norm;
tindex++;
tindex &= mask;
}
// zeropadding
for(n=framesize; n<(framesize<<1); n++) processbuf[n] = 0.;
// call analysis procedures
snac_autocorrelation(s);
snac_normalize(s);
snac_pickpeak(s);
snac_periodandfidelity(s);
}
static void snac_autocorrelation(tSNAC* const s)
{
int n, m;
int framesize = s->framesize;
int fftsize = framesize * 2;
float *processbuf = s->processbuf;
float *spectrumbuf = s->spectrumbuf;
REALFFT(fftsize, processbuf);
// compute power spectrum
processbuf[0] *= processbuf[0]; // DC
processbuf[framesize] *= processbuf[framesize]; // Nyquist
for(n=1; n<framesize; n++)
{
processbuf[n] = processbuf[n] * processbuf[n]
+ processbuf[fftsize-n] * processbuf[fftsize-n]; // imag coefficients appear reversed
processbuf[fftsize-n] = 0.;
}
// store power spectrum up to SR/4 for possible later use
for(m=0; m<(framesize>>1); m++)
{
spectrumbuf[m] = processbuf[m];
}
// transform power spectrum to autocorrelation function
REALIFFT(fftsize, processbuf);
return;
}
static void snac_normalize(tSNAC* const s)
{
int framesize = s->framesize;
int framesizeplustimeindex = s->framesize + s->timeindex;
int timeindexminusone = s->timeindex - 1;
int n, m;
int mask = framesize - 1;
int seek = framesize * SEEK;
float *inputbuf = s->inputbuf;
float *processbuf= s->processbuf;
float signal1, signal2;
// minimum RMS implemented as minimum autocorrelation at index 0
// functionally equivalent to white noise floor
float rms = s->minrms / sqrt(1.0f / (float)framesize);
float minrzero = rms * rms;
float rzero = processbuf[0];
if(rzero < minrzero) rzero = minrzero;
double normintegral = (double)rzero * 2.;
// normalize biased autocorrelation function
// inputbuf is circular buffer: timeindex may be non-zero when overlap > 1
processbuf[0] = 1;
for(n=1, m=s->timeindex+1; n<seek; n++, m++)
{
signal1 = inputbuf[(n + timeindexminusone)&mask];
signal2 = inputbuf[(framesizeplustimeindex - n)&mask];
normintegral -= (double)(signal1 * signal1 + signal2 * signal2);
processbuf[n] /= (float)normintegral * 0.5f;
}
// flush instable function tail
for(n = seek; n<framesize; n++) processbuf[n] = 0.;
return;
}
static void snac_periodandfidelity(tSNAC* const s)
{
float periodlength;
if(s->periodindex)
{
periodlength = (float)s->periodindex +
interpolate3phase(s->processbuf, s->periodindex);
if(periodlength < 8) periodlength = snac_spectralpeak(s, periodlength);
s->periodlength = periodlength;
s->fidelity = interpolate3max(s->processbuf, s->periodindex);
}
return;
}
// select the peak which most probably represents period length
static void snac_pickpeak(tSNAC* const s)
{
int n, peakindex=0;
int seek = s->framesize * SEEK;
float *processbuf= s->processbuf;
float maxvalue = 0.;
float biasedpeak;
float *biasbuf = s->biasbuf;
// skip main lobe
for(n=1; n<seek; n++)
{
if(processbuf[n] < 0.) break;
}
// find interpolated / biased maximum in SNAC function
// interpolation finds the 'real maximum'
// biasing favours the first candidate
for(; n<seek-1; n++)
{
if(processbuf[n] >= processbuf[n-1])
{
if(processbuf[n] > processbuf[n+1]) // we have a local peak
{
biasedpeak = interpolate3max(processbuf, n) * biasbuf[n];
if(biasedpeak > maxvalue)
{
maxvalue = biasedpeak;
peakindex = n;
}
}
}
}
s->periodindex = peakindex;
return;
}
// verify period length via frequency domain (up till SR/4)
// frequency domain is more precise than lag domain for period lengths < 8
// argument 'periodlength' is initial estimation from autocorrelation
static float snac_spectralpeak(tSNAC* const s, float periodlength)
{
if(periodlength < 4.) return periodlength;
float max = 0.;
int n, startbin, stopbin, peakbin = 0;
int spectrumsize = s->framesize>>1;
float *spectrumbuf = s->spectrumbuf;
float peaklocation = (float)(s->framesize * 2.) / periodlength;
startbin = (int)(peaklocation * 0.8 + 0.5);
if(startbin < 1) startbin = 1;
stopbin = (int)(peaklocation * 1.25 + 0.5);
if(stopbin >= spectrumsize - 1) stopbin = spectrumsize - 1;
for(n=startbin; n<stopbin; n++)
{
if(spectrumbuf[n] >= spectrumbuf[n-1])
{
if(spectrumbuf[n] > spectrumbuf[n+1])
{
if(spectrumbuf[n] > max)
{
max = spectrumbuf[n];
peakbin = n;
}
}
}
}
// calculate amplitudes in peak region
for(n=(peakbin-1); n<(peakbin+2); n++)
{
spectrumbuf[n] = sqrt(spectrumbuf[n]);
}
peaklocation = (float)peakbin + interpolate3phase(spectrumbuf, peakbin);
periodlength = (float)(s->framesize * 2.0f) / peaklocation;
return periodlength;
}
// modified logarithmic bias function
static void snac_biasbuf(tSNAC* const s)
{
int n;
int maxperiod = (int)(s->framesize * (float)SEEK);
float bias = s->biasfactor / log((float)(maxperiod - 4));
float *biasbuf = s->biasbuf;
for(n=0; n<5; n++) // periods < 5 samples can't be tracked
{
biasbuf[n] = 0.;
}
for(n=5; n<maxperiod; n++)
{
biasbuf[n] = 1.0f - (float)log(n - 4) * bias;
}
}