?? pitch_a.c
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/*
ITU-T G.729A Speech Coder ANSI-C Source Code
Version 1.1 Last modified: September 1996
Copyright (c) 1996,
AT&T, France Telecom, NTT, Universite de Sherbrooke
All rights reserved.
*/
/*---------------------------------------------------------------------------*
* Pitch related functions *
* ~~~~~~~~~~~~~~~~~~~~~~~ *
*---------------------------------------------------------------------------*/
#include "typedef.h"
#include "basic_op.h"
#include "oper_32b.h"
#include "ld8a.h"
#include "tab_ld8a.h"
/*---------------------------------------------------------------------------*
* Function Pitch_ol_fast *
* ~~~~~~~~~~~~~~~~~~~~~~~ *
* Compute the open loop pitch lag. (fast version) *
* *
*---------------------------------------------------------------------------*/
Word16 Pitch_ol_fast( /* output: open loop pitch lag */
Word16 signal[], /* input : signal used to compute the open loop pitch */
/* signal[-pit_max] to signal[-1] should be known */
Word16 pit_max, /* input : maximum pitch lag */
Word16 L_frame /* input : length of frame to compute pitch */
)
{
Word16 i, j;
Word16 max1, max2, max3;
Word16 max_h, max_l, ener_h, ener_l;
Word16 T1, T2, T3;
Word16 *p, *p1;
Word32 max, sum, L_temp;
/* Scaled signal */
Word16 scaled_signal[L_FRAME+PIT_MAX];
Word16 *scal_sig;
scal_sig = &scaled_signal[pit_max];
/*--------------------------------------------------------*
* Verification for risk of overflow. *
*--------------------------------------------------------*/
Overflow = 0;
sum = 0;
for(i= -pit_max; i< L_frame; i+=2)
sum = L_mac(sum, signal[i], signal[i]);
/*--------------------------------------------------------*
* Scaling of input signal. *
* *
* if Overflow -> scal_sig[i] = signal[i]>>3 *
* else if sum < 1^20 -> scal_sig[i] = signal[i]<<3 *
* else -> scal_sig[i] = signal[i] *
*--------------------------------------------------------*/
if(Overflow == 1)
{
for(i=-pit_max; i<L_frame; i++)
{
scal_sig[i] = shr(signal[i], 3);
}
}
else {
L_temp = L_sub(sum, (Word32)1048576L);
if ( L_temp < (Word32)0 ) /* if (sum < 2^20) */
{
for(i=-pit_max; i<L_frame; i++)
{
scal_sig[i] = shl(signal[i], 3);
}
}
else
{
for(i=-pit_max; i<L_frame; i++)
{
scal_sig[i] = signal[i];
}
}
}
/*--------------------------------------------------------------------*
* The pitch lag search is divided in three sections. *
* Each section cannot have a pitch multiple. *
* We find a maximum for each section. *
* We compare the maxima of each section by favoring small lag. *
* *
* First section: lag delay = 20 to 39 *
* Second section: lag delay = 40 to 79 *
* Third section: lag delay = 80 to 143 *
*--------------------------------------------------------------------*/
/* First section */
max = MIN_32;
T1 = 20; /* Only to remove warning from some compilers */
for (i = 20; i < 40; i++) {
p = scal_sig;
p1 = &scal_sig[-i];
sum = 0;
for (j=0; j<L_frame; j+=2, p+=2, p1+=2)
sum = L_mac(sum, *p, *p1);
L_temp = L_sub(sum, max);
if (L_temp > 0) { max = sum; T1 = i; }
}
/* compute energy of maximum */
sum = 1; /* to avoid division by zero */
p = &scal_sig[-T1];
for(i=0; i<L_frame; i+=2, p+=2)
sum = L_mac(sum, *p, *p);
/* max1 = max/sqrt(energy) */
/* This result will always be on 16 bits !! */
sum = Inv_sqrt(sum); /* 1/sqrt(energy), result in Q30 */
L_Extract(max, &max_h, &max_l);
L_Extract(sum, &ener_h, &ener_l);
sum = Mpy_32(max_h, max_l, ener_h, ener_l);
max1 = extract_l(sum);
/* Second section */
max = MIN_32;
T2 = 40; /* Only to remove warning from some compilers */
for (i = 40; i < 80; i++) {
p = scal_sig;
p1 = &scal_sig[-i];
sum = 0;
for (j=0; j<L_frame; j+=2, p+=2, p1+=2)
sum = L_mac(sum, *p, *p1);
L_temp = L_sub(sum, max);
if (L_temp > 0) { max = sum; T2 = i; }
}
/* compute energy of maximum */
sum = 1; /* to avoid division by zero */
p = &scal_sig[-T2];
for(i=0; i<L_frame; i+=2, p+=2)
sum = L_mac(sum, *p, *p);
/* max2 = max/sqrt(energy) */
/* This result will always be on 16 bits !! */
sum = Inv_sqrt(sum); /* 1/sqrt(energy), result in Q30 */
L_Extract(max, &max_h, &max_l);
L_Extract(sum, &ener_h, &ener_l);
sum = Mpy_32(max_h, max_l, ener_h, ener_l);
max2 = extract_l(sum);
/* Third section */
max = MIN_32;
T3 = 80; /* Only to remove warning from some compilers */
for (i = 80; i < 143; i+=2) {
p = scal_sig;
p1 = &scal_sig[-i];
sum = 0;
for (j=0; j<L_frame; j+=2, p+=2, p1+=2)
sum = L_mac(sum, *p, *p1);
L_temp = L_sub(sum, max);
if (L_temp > 0) { max = sum; T3 = i; }
}
/* Test around max3 */
i = T3;
p = scal_sig;
p1 = &scal_sig[-(i+1)];
sum = 0;
for (j=0; j<L_frame; j+=2, p+=2, p1+=2)
sum = L_mac(sum, *p, *p1);
L_temp = L_sub(sum, max);
if (L_temp > 0) { max = sum; T3 = i+(Word16)1; }
p = scal_sig;
p1 = &scal_sig[-(i-1)];
sum = 0;
for (j=0; j<L_frame; j+=2, p+=2, p1+=2)
sum = L_mac(sum, *p, *p1);
L_temp = L_sub(sum, max);
if (L_temp > 0) { max = sum; T3 = i-(Word16)1; }
/* compute energy of maximum */
sum = 1; /* to avoid division by zero */
p = &scal_sig[-T3];
for(i=0; i<L_frame; i+=2, p+=2)
sum = L_mac(sum, *p, *p);
/* max1 = max/sqrt(energy) */
/* This result will always be on 16 bits !! */
sum = Inv_sqrt(sum); /* 1/sqrt(energy), result in Q30 */
L_Extract(max, &max_h, &max_l);
L_Extract(sum, &ener_h, &ener_l);
sum = Mpy_32(max_h, max_l, ener_h, ener_l);
max3 = extract_l(sum);
/*-----------------------*
* Test for multiple. *
*-----------------------*/
/* if( abs(T2*2 - T3) < 5) */
/* max2 += max3 * 0.25; */
i = sub(shl(T2,1), T3);
j = sub(abs_s(i), 5);
if(j < 0)
max2 = add(max2, shr(max3, 2));
/* if( abs(T2*3 - T3) < 7) */
/* max2 += max3 * 0.25; */
i = add(i, T2);
j = sub(abs_s(i), 7);
if(j < 0)
max2 = add(max2, shr(max3, 2));
/* if( abs(T1*2 - T2) < 5) */
/* max1 += max2 * 0.20; */
i = sub(shl(T1,1), T2);
j = sub(abs_s(i), 5);
if(j < 0)
max1 = add(max1, mult(max2, 6554));
/* if( abs(T1*3 - T2) < 7) */
/* max1 += max2 * 0.20; */
i = add(i, T1);
j = sub(abs_s(i), 7);
if(j < 0)
max1 = add(max1, mult(max2, 6554));
/*--------------------------------------------------------------------*
* Compare the 3 sections maxima. *
*--------------------------------------------------------------------*/
if( sub(max1, max2) < 0 ) {max1 = max2; T1 = T2; }
if( sub(max1, max3) <0 ) {T1 = T3; }
return T1;
}
/*--------------------------------------------------------------------------*
* Function Dot_Product() *
* ~~~~~~~~~~~~~~~~~~~~~~ *
*--------------------------------------------------------------------------*/
Word32 Dot_Product( /* (o) :Result of scalar product. */
Word16 x[], /* (i) :First vector. */
Word16 y[], /* (i) :Second vector. */
Word16 lg /* (i) :Number of point. */
)
{
Word16 i;
Word32 sum;
sum = 0;
for(i=0; i<lg; i++)
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