?? qua_gain.c
字號(hào):
/*
ITU-T G.729 Speech Coder ANSI-C Source Code
Version 3.3 Last modified: December 26, 1995
Copyright (c) 1996,
AT&T, France Telecom, NTT, Universite de Sherbrooke, Lucent Technologies
All rights reserved.
*/
#include "typedef.h"
#include "basic_op.h"
#include "oper_32b.h"
#include "ld8k.h"
#include "tab_ld8k.h"
static void Gbk_presel(
Word16 best_gain[], /* (i) [0] Q9 : unquantized pitch gain */
/* (i) [1] Q2 : unquantized code gain */
Word16 *cand1, /* (o) : index of best 1st stage vector */
Word16 *cand2, /* (o) : index of best 2nd stage vector */
Word16 gcode0 /* (i) Q4 : presearch for gain codebook */
);
/*---------------------------------------------------------------------------*
* Function Qua_gain *
* ~~~~~~~~~~~~~~~~~~ *
* Inputs: *
* code[] :Innovative codebook. *
* g_coeff[] :Correlations compute for pitch. *
* L_subfr :Subframe length. *
* *
* Outputs: *
* gain_pit :Quantized pitch gain. *
* gain_cod :Quantized code gain. *
* *
* Return: *
* Index of quantization. *
* *
*--------------------------------------------------------------------------*/
Word16 Qua_gain(
Word16 code[], /* (i) Q13 :Innovative vector. */
Word16 g_coeff[], /* (i) :Correlations <xn y1> -2<y1 y1> */
/* <y2,y2>, -2<xn,y2>, 2<y1,y2> */
Word16 exp_coeff[], /* (i) :Q-Format g_coeff[] */
Word16 L_subfr, /* (i) :Subframe length. */
Word16 *gain_pit, /* (o) Q14 :Pitch gain. */
Word16 *gain_cod, /* (o) Q1 :Code gain. */
Word16 tameflag /* (i) : set to 1 if taming is needed */
)
{
Word16 i, j, index1, index2;
Word16 cand1, cand2;
Word16 exp, gcode0, exp_gcode0, gcode0_org, e_min ;
Word16 nume, denom, inv_denom;
Word16 exp1,exp2,exp_nume,exp_denom,exp_inv_denom,sft,tmp;
Word16 g_pitch, g2_pitch, g_code, g2_code, g_pit_cod;
Word16 coeff[5], coeff_lsf[5];
Word16 exp_min[5];
Word32 L_gbk12;
Word32 L_tmp, L_dist_min, L_temp, L_tmp1, L_tmp2, L_acc, L_accb;
Word16 best_gain[2];
/* Gain predictor, Past quantized energies = -14.0 in Q10 */
static Word16 past_qua_en[4] = { -14336, -14336, -14336, -14336 };
/*---------------------------------------------------*
*- energy due to innovation -*
*- predicted energy -*
*- predicted codebook gain => gcode0[exp_gcode0] -*
*---------------------------------------------------*/
Gain_predict( past_qua_en, code, L_subfr, &gcode0, &exp_gcode0 );
/*-----------------------------------------------------------------*
* pre-selection *
*-----------------------------------------------------------------*/
/*-----------------------------------------------------------------*
* calculate best gain *
* *
* tmp = -1./(4.*coeff[0]*coeff[2]-coeff[4]*coeff[4]) ; *
* best_gain[0] = (2.*coeff[2]*coeff[1]-coeff[3]*coeff[4])*tmp ; *
* best_gain[1] = (2.*coeff[0]*coeff[3]-coeff[1]*coeff[4])*tmp ; *
* gbk_presel(best_gain,&cand1,&cand2,gcode0) ; *
* *
*-----------------------------------------------------------------*/
/*-----------------------------------------------------------------*
* tmp = -1./(4.*coeff[0]*coeff[2]-coeff[4]*coeff[4]) ; *
*-----------------------------------------------------------------*/
L_tmp1 = L_mult( g_coeff[0], g_coeff[2] );
exp1 = add( add( exp_coeff[0], exp_coeff[2] ), 1-2 );
L_tmp2 = L_mult( g_coeff[4], g_coeff[4] );
exp2 = add( add( exp_coeff[4], exp_coeff[4] ), 1 );
if( sub(exp1, exp2)>0 ){
L_tmp = L_sub( L_shr( L_tmp1, sub(exp1,exp2) ), L_tmp2 );
exp = exp2;
}
else{
L_tmp = L_sub( L_tmp1, L_shr( L_tmp2, sub(exp2,exp1) ) );
exp = exp1;
}
sft = norm_l( L_tmp );
denom = extract_h( L_shl(L_tmp, sft) );
exp_denom = sub( add( exp, sft ), 16 );
inv_denom = div_s(16384,denom);
inv_denom = negate( inv_denom );
exp_inv_denom = sub( 14+15, exp_denom );
/*-----------------------------------------------------------------*
* best_gain[0] = (2.*coeff[2]*coeff[1]-coeff[3]*coeff[4])*tmp ; *
*-----------------------------------------------------------------*/
L_tmp1 = L_mult( g_coeff[2], g_coeff[1] );
exp1 = add( exp_coeff[2], exp_coeff[1] );
L_tmp2 = L_mult( g_coeff[3], g_coeff[4] );
exp2 = add( add( exp_coeff[3], exp_coeff[4] ), 1 );
if( sub(exp1, exp2)>0 ){
L_tmp = L_sub( L_shr( L_tmp1, add(sub(exp1,exp2),1 )), L_shr( L_tmp2,1 ) );
exp = sub(exp2,1);
}
else{
L_tmp = L_sub( L_shr( L_tmp1,1 ), L_shr( L_tmp2, add(sub(exp2,exp1),1 )) );
exp = sub(exp1,1);
}
sft = norm_l( L_tmp );
nume = extract_h( L_shl(L_tmp, sft) );
exp_nume = sub( add( exp, sft ), 16 );
sft = sub( add( exp_nume, exp_inv_denom ), (9+16-1) );
L_acc = L_shr( L_mult( nume,inv_denom ), sft );
best_gain[0] = extract_h( L_acc ); /*-- best_gain[0]:Q9 --*/
if (tameflag == 1){
if(sub(best_gain[0], GPCLIP2) > 0) best_gain[0] = GPCLIP2;
}
/*-----------------------------------------------------------------*
* best_gain[1] = (2.*coeff[0]*coeff[3]-coeff[1]*coeff[4])*tmp ; *
*-----------------------------------------------------------------*/
L_tmp1 = L_mult( g_coeff[0], g_coeff[3] );
exp1 = add( exp_coeff[0], exp_coeff[3] ) ;
L_tmp2 = L_mult( g_coeff[1], g_coeff[4] );
exp2 = add( add( exp_coeff[1], exp_coeff[4] ), 1 );
if( sub(exp1, exp2)>0 ){
L_tmp = L_sub( L_shr( L_tmp1, add(sub(exp1,exp2),1) ), L_shr( L_tmp2,1 ) );
exp = sub(exp2,1);
}
else{
L_tmp = L_sub( L_shr( L_tmp1,1 ), L_shr( L_tmp2, add(sub(exp2,exp1),1) ) );
exp = sub(exp1,1);
}
sft = norm_l( L_tmp );
nume = extract_h( L_shl(L_tmp, sft) );
exp_nume = sub( add( exp, sft ), 16 );
sft = sub( add( exp_nume, exp_inv_denom ), (2+16-1) );
L_acc = L_shr( L_mult( nume,inv_denom ), sft );
best_gain[1] = extract_h( L_acc ); /*-- best_gain[1]:Q2 --*/
/*--- Change Q-format of gcode0 ( Q[exp_gcode0] -> Q4 ) ---*/
if( sub(exp_gcode0,4) >= 0 ){
gcode0_org = shr( gcode0, sub(exp_gcode0,4) );
}
else{
L_acc = L_deposit_l( gcode0 );
L_acc = L_shl( L_acc, sub( (4+16), exp_gcode0 ) );
gcode0_org = extract_h( L_acc ); /*-- gcode0_org:Q4 --*/
}
/*----------------------------------------------*
* - presearch for gain codebook - *
*----------------------------------------------*/
Gbk_presel(best_gain, &cand1, &cand2, gcode0_org );
/*---------------------------------------------------------------------------*
* *
* Find the best quantizer. *
* *
* dist_min = MAX_32; *
* for ( i=0 ; i<NCAN1 ; i++ ){ *
* for ( j=0 ; j<NCAN2 ; j++ ){ *
* g_pitch = gbk1[cand1+i][0] + gbk2[cand2+j][0]; *
* g_code = gcode0 * (gbk1[cand1+i][1] + gbk2[cand2+j][1]); *
* dist = g_pitch*g_pitch * coeff[0] *
* + g_pitch * coeff[1] *
* + g_code*g_code * coeff[2] *
* + g_code * coeff[3] *
* + g_pitch*g_code * coeff[4] ; *
* *
* if (dist < dist_min){ *
* dist_min = dist; *
* indice1 = cand1 + i ; *
* indice2 = cand2 + j ; *
* } *
* } *
* } *
* *
* g_pitch = Q13 *
* g_pitch*g_pitch = Q11:(13+13+1-16) *
* g_code = Q[exp_gcode0-3]:(exp_gcode0+(13-1)+1-16) *
* g_code*g_code = Q[2*exp_gcode0-21]:(exp_gcode0-3+exp_gcode0-3+1-16) *
* g_pitch*g_code = Q[exp_gcode0-5]:(13+exp_gcode0-3+1-16) *
* *
* term 0: g_pitch*g_pitch*coeff[0] ;exp_min0 = 13 +exp_coeff[0] *
* term 1: g_pitch *coeff[1] ;exp_min1 = 14 +exp_coeff[1] *
* term 2: g_code*g_code *coeff[2] ;exp_min2 = 2*exp_gcode0-21+exp_coeff[2] *
* term 3: g_code *coeff[3] ;exp_min3 = exp_gcode0 - 3+exp_coeff[3] *
* term 4: g_pitch*g_code *coeff[4] ;exp_min4 = exp_gcode0 - 4+exp_coeff[4] *
* *
*---------------------------------------------------------------------------*/
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