void filterbank_compute_bank32(FilterBank *bank, spx_word32_t *ps, spx_word32_t *mel)
{
int i;
for (i=0;i<bank->nb_banks;i++)
mel[i] = 0;
for (i=0;i<bank->len;i++)
{
int id;
id = bank->bank_left[i];
mel[id] += MULT16_32_P15(bank->filter_left[i],ps[i]);
id = bank->bank_right[i];
mel[id] += MULT16_32_P15(bank->filter_right[i],ps[i]);
}
/* Think I can safely disable normalisation that for fixed-point (and probably float as well) */
#ifndef FIXED_POINT
/*for (i=0;i<bank->nb_banks;i++)
mel[i] = MULT16_32_P15(Q15(bank->scaling[i]),mel[i]);
*/
#endif
}
FilterBank *filterbank_new(int banks, spx_word32_t sampling, int len, int type)
{
FilterBank *bank;
spx_word32_t df;
spx_word32_t max_mel, mel_interval;
int i;
int id1;
int id2;
df = DIV32(SHL32(sampling,15),MULT16_16(2,len));
max_mel = toBARK(EXTRACT16(sampling/2));
mel_interval = PDIV32(max_mel,banks-1);
bank = (FilterBank*)speex_alloc(sizeof(FilterBank));
bank->nb_banks = banks;
bank->len = len;
bank->bank_left = (int*)speex_alloc(len*sizeof(int));
bank->bank_right = (int*)speex_alloc(len*sizeof(int));
bank->filter_left = (spx_word16_t*)speex_alloc(len*sizeof(spx_word16_t));
bank->filter_right = (spx_word16_t*)speex_alloc(len*sizeof(spx_word16_t));
/* Think I can safely disable normalisation that for fixed-point (and probably float as well) */
#ifndef FIXED_POINT
bank->scaling = (float*)speex_alloc(banks*sizeof(float));
#endif
for (i=0;i<len;i++)
{
spx_word16_t curr_freq;
spx_word32_t mel;
spx_word16_t val;
curr_freq = EXTRACT16(MULT16_32_P15(i,df));
mel = toBARK(curr_freq);
if (mel > max_mel)
break;
#ifdef FIXED_POINT
id1 = DIV32(mel,mel_interval);
#else
id1 = (int)(floor(mel/mel_interval));
#endif
if (id1>banks-2)
{
id1 = banks-2;
val = Q15_ONE;
} else {
val = DIV32_16(mel - id1*mel_interval,EXTRACT16(PSHR32(mel_interval,15)));
}
id2 = id1+1;
bank->bank_left[i] = id1;
bank->filter_left[i] = SUB16(Q15_ONE,val);
bank->bank_right[i] = id2;
bank->filter_right[i] = val;
}
/* Think I can safely disable normalisation for fixed-point (and probably float as well) */
#ifndef FIXED_POINT
for (i=0;i<bank->nb_banks;i++)
bank->scaling[i] = 0;
for (i=0;i<bank->len;i++)
{
int id = bank->bank_left[i];
bank->scaling[id] += bank->filter_left[i];
id = bank->bank_right[i];
bank->scaling[id] += bank->filter_right[i];
}
for (i=0;i<bank->nb_banks;i++)
bank->scaling[i] = Q15_ONE/(bank->scaling[i]);
#endif
return bank;
}
void computeLP(word16_t signal[], word16_t LPCoefficientsQ12[], word32_t reflectionCoefficients[], word32_t autoCorrelationCoefficients[], word32_t noLagAutocorrelationCoefficients[], int8_t *autoCorrelationCoefficientsScale, uint8_t autoCorrelationCoefficientsNumber)
{
int i,j;
word16_t windowedSignal[L_LP_ANALYSIS_WINDOW];
word64_t acc64=0; /* acc on 64 bits */
int rightShiftToNormalise=0;
word32_t residualEnergy; /* interally compute by autoCorrelation2LP and extracted for DTX only, useless here */
/*********************************************************************/
/* Compute the windowed signal according to spec 3.2.1 eq4 */
/*********************************************************************/
for (i=0; i<L_LP_ANALYSIS_WINDOW; i++) {
windowedSignal[i] = MULT16_16_P15(signal[i], wlp[i]); /* signal in Q0, wlp in Q0.15, windowedSignal in Q0 */
}
/*********************************************************************************/
/* Compute the autoCorrelation coefficients r[0..10] according to spec 3.2.1 eq5 */
/*********************************************************************************/
/* Compute autoCorrelationCoefficients[0] first as it is the highest number and normalise it on 32 bits then apply the same normalisation to the other coefficients */
/* autoCorrelationCoefficients are normalised on 32 bits and then considered as Q31 in range [-1,1[ */
/* autoCorrelationCoefficients[0] is computed on 64 bits as it is likely to overflow 32 bits */
for (i=0; i<L_LP_ANALYSIS_WINDOW; i++) {
acc64 = MAC64(acc64, windowedSignal[i], windowedSignal[i]);
}
if (acc64==0) {
acc64 = 1; /* spec 3.2.1: To avoid arithmetic problems for low-level input signals the value of r(0) has a lower boundary of r(0) = 1.0 */
}
/* normalise the acc64 on 32 bits */
if (acc64>MAXINT32) {
do {
acc64 = SHR(acc64,1);
rightShiftToNormalise++;
} while (acc64>MAXINT32);
autoCorrelationCoefficients[0] = acc64;
} else {
rightShiftToNormalise = -countLeadingZeros((word32_t)acc64);
autoCorrelationCoefficients[0] = SHL((word32_t)acc64, -rightShiftToNormalise);
}
/* give current autoCorrelation coefficients scale to the output */
*autoCorrelationCoefficientsScale = -rightShiftToNormalise;
/* compute autoCorrelationCoefficients 1 to requested number (10 - no VAD - or 12 if VAD is enabled */
if (rightShiftToNormalise>0) { /* acc64 was not fitting on 32 bits so compute the other sum on 64 bits too */
for (i=1; i<autoCorrelationCoefficientsNumber; i++) {
/* compute the sum in the 64 bits acc*/
acc64=0;
for (j=i; j<L_LP_ANALYSIS_WINDOW; j++) {
acc64 = ADD64_32(acc64, MULT16_16(windowedSignal[j], windowedSignal[j-i]));
}
/* normalise it */
autoCorrelationCoefficients[i] = SHR(acc64 ,rightShiftToNormalise);
}
} else { /* acc64 was fitting on 32 bits, compute the other sum on 32 bits only as it is faster */
for (i=1; i<autoCorrelationCoefficientsNumber; i++) {
/* compute the sum in the 64 bits acc*/
word32_t acc32=0;
for (j=i; j<L_LP_ANALYSIS_WINDOW; j++) {
acc32 = MAC16_16(acc32, windowedSignal[j], windowedSignal[j-i]);
}
/* normalise it */
autoCorrelationCoefficients[i] = SHL(acc32, -rightShiftToNormalise);
}
}
/* save autocorrelation before applying lag window as they are requested like this for DTX */
for (i=0; i<autoCorrelationCoefficientsNumber; i++) {
noLagAutocorrelationCoefficients[i] = autoCorrelationCoefficients[i];
}
/* apply lag window on the autocorrelation coefficients spec 3.2.1 eq7 */
/* this check shall be useless but it makes some compiler happy */
if (autoCorrelationCoefficientsNumber>NB_LSP_COEFF+3) {
autoCorrelationCoefficientsNumber = NB_LSP_COEFF+3;
}
for (i=1; i<autoCorrelationCoefficientsNumber; i++) {
autoCorrelationCoefficients[i] = MULT16_32_P15(wlag[i], autoCorrelationCoefficients[i]); /* wlag in Q15 */
//autoCorrelationCoefficients[i] = MULT32_32_Q31(wlag[i], autoCorrelationCoefficients[i]); /* wlag in Q31 */
}
/* convert to LP using Levinson-Durbin algo described in sepc 3.2.2 */
autoCorrelation2LP(autoCorrelationCoefficients, LPCoefficientsQ12, reflectionCoefficients, &residualEnergy);
return;
}
