MMDVM_CM/DMR2M17/codec2/qbase.cpp

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2020-11-02 00:11:30 -05:00
#include <assert.h>
#include <math.h>
#include "qbase.h"
/*---------------------------------------------------------------------------*\
quantise
Quantises vec by choosing the nearest vector in codebook cb, and
returns the vector index. The squared error of the quantised vector
is added to se.
\*---------------------------------------------------------------------------*/
long CQbase::quantise(const float *cb, float vec[], float w[], int k, int m, float *se)
/* float cb[][K]; current VQ codebook */
/* float vec[]; vector to quantise */
/* float w[]; weighting vector */
/* int k; dimension of vectors */
/* int m; size of codebook */
/* float *se; accumulated squared error */
{
float e; /* current error */
long besti; /* best index so far */
float beste; /* best error so far */
long j;
int i;
float diff;
besti = 0;
beste = 1E32;
for(j=0; j<m; j++)
{
e = 0.0;
for(i=0; i<k; i++)
{
diff = cb[j*k+i]-vec[i];
e += (diff*w[i] * diff*w[i]);
}
if (e < beste)
{
beste = e;
besti = j;
}
}
*se += beste;
return(besti);
}
/*---------------------------------------------------------------------------*\
FUNCTION....: encode_WoE()
AUTHOR......: Jean-Marc Valin & David Rowe
DATE CREATED: 11 May 2012
Joint Wo and LPC energy vector quantiser developed my Jean-Marc
Valin. Returns index, and updated states xq[].
\*---------------------------------------------------------------------------*/
int CQbase::encode_WoE(MODEL *model, float e, float xq[])
{
int i, n1;
float x[2];
float err[2];
float w[2];
const float *codebook1 = ge_cb[0].cb;
int nb_entries = ge_cb[0].m;
int ndim = ge_cb[0].k;
assert((1<<WO_E_BITS) == nb_entries);
if (e < 0.0) e = 0; /* occasional small negative energies due LPC round off I guess */
x[0] = log10f((model->Wo/PI)*4000.0/50.0)/log10f(2);
x[1] = 10.0*log10f(1e-4 + e);
compute_weights2(x, xq, w);
for (i=0; i<ndim; i++)
err[i] = x[i]-ge_coeff[i]*xq[i];
n1 = find_nearest_weighted(codebook1, nb_entries, err, w, ndim);
for (i=0; i<ndim; i++)
{
xq[i] = ge_coeff[i]*xq[i] + codebook1[ndim*n1+i];
err[i] -= codebook1[ndim*n1+i];
}
//printf("enc: %f %f (%f)(%f) \n", xq[0], xq[1], e, 10.0*log10(1e-4 + e));
return n1;
}
/*---------------------------------------------------------------------------*\
FUNCTION....: decode_WoE()
AUTHOR......: Jean-Marc Valin & David Rowe
DATE CREATED: 11 May 2012
Joint Wo and LPC energy vector quantiser developed my Jean-Marc
Valin. Given index and states xq[], returns Wo & E, and updates
states xq[].
\*---------------------------------------------------------------------------*/
void CQbase::decode_WoE(C2CONST *c2const, MODEL *model, float *e, float xq[], int n1)
{
int i;
const float *codebook1 = ge_cb[0].cb;
int ndim = ge_cb[0].k;
float Wo_min = c2const->Wo_min;
float Wo_max = c2const->Wo_max;
for (i=0; i<ndim; i++)
{
xq[i] = ge_coeff[i]*xq[i] + codebook1[ndim*n1+i];
}
//printf("dec: %f %f\n", xq[0], xq[1]);
model->Wo = powf(2.0, xq[0])*(PI*50.0)/4000.0;
/* bit errors can make us go out of range leading to all sorts of
probs like seg faults */
if (model->Wo > Wo_max) model->Wo = Wo_max;
if (model->Wo < Wo_min) model->Wo = Wo_min;
model->L = PI/model->Wo; /* if we quantise Wo re-compute L */
*e = exp10f(xq[1]/10.0);
}
void CQbase::compute_weights2(const float *x, const float *xp, float *w)
{
w[0] = 30;
w[1] = 1;
if (x[1]<0)
{
w[0] *= .6;
w[1] *= .3;
}
if (x[1]<-10)
{
w[0] *= .3;
w[1] *= .3;
}
/* Higher weight if pitch is stable */
if (fabsf(x[0]-xp[0])<.2)
{
w[0] *= 2;
w[1] *= 1.5;
}
else if (fabsf(x[0]-xp[0])>.5) /* Lower if not stable */
{
w[0] *= .5;
}
/* Lower weight for low energy */
if (x[1] < xp[1]-10)
{
w[1] *= .5;
}
if (x[1] < xp[1]-20)
{
w[1] *= .5;
}
//w[0] = 30;
//w[1] = 1;
/* Square the weights because it's applied on the squared error */
w[0] *= w[0];
w[1] *= w[1];
}
int CQbase::find_nearest_weighted(const float *codebook, int nb_entries, float *x, const float *w, int ndim)
{
int i, j;
float min_dist = 1e15;
int nearest = 0;
for (i=0; i<nb_entries; i++)
{
float dist=0;
for (j=0; j<ndim; j++)
dist += w[j]*(x[j]-codebook[i*ndim+j])*(x[j]-codebook[i*ndim+j]);
if (dist<min_dist)
{
min_dist = dist;
nearest = i;
}
}
return nearest;
}
/*---------------------------------------------------------------------------*\
FUNCTION....: encode_log_Wo()
AUTHOR......: David Rowe
DATE CREATED: 22/8/2010
Encodes Wo in the log domain using a WO_LEVELS quantiser.
\*---------------------------------------------------------------------------*/
int CQbase::encode_log_Wo(C2CONST *c2const, float Wo, int bits)
{
int index, Wo_levels = 1<<bits;
float Wo_min = c2const->Wo_min;
float Wo_max = c2const->Wo_max;
float norm;
norm = (log10f(Wo) - log10f(Wo_min))/(log10f(Wo_max) - log10f(Wo_min));
index = floorf(Wo_levels * norm + 0.5);
if (index < 0 ) index = 0;
if (index > (Wo_levels-1)) index = Wo_levels-1;
return index;
}
/*---------------------------------------------------------------------------*\
FUNCTION....: decode_log_Wo()
AUTHOR......: David Rowe
DATE CREATED: 22/8/2010
Decodes Wo using a WO_LEVELS quantiser in the log domain.
\*---------------------------------------------------------------------------*/
float CQbase::decode_log_Wo(C2CONST *c2const, int index, int bits)
{
float Wo_min = c2const->Wo_min;
float Wo_max = c2const->Wo_max;
float step;
float Wo;
int Wo_levels = 1<<bits;
step = (log10f(Wo_max) - log10f(Wo_min))/Wo_levels;
Wo = log10f(Wo_min) + step*(index);
return exp10f(Wo);
}