www.pudn.com > AVS_M_ver10.rar > dec_lf.c


/*
***********************************************************************
* COPYRIGHT AND WARRANTY INFORMATION
*
* Copyright 2007 Audio Video Coding Standard, Part Ⅹ
*
* This software module was developed by AVS Audio sub-group
*
* DISCLAIMER OF WARRANTY
*
* These software programs are available to the users without any
* license fee or royalty on an "as is" basis. The AVS disclaims
* any and all warranties, whether express, implied, or statutory,
* including any implied warranties of merchantability or of fitness
* for a particular purpose. In no event shall the contributors or
* the AVS be liable for any incidental, punitive, or consequential
* damages of any kind whatsoever arising from the use of this program.
*
* This disclaimer of warranty extends to the user of this program
* and user's customers, employees, agents, transferees, successors,
* and assigns.
*
* The AVS does not represent or warrant that the program furnished
* hereunder are free of infringement of any third-party patents.
* Commercial implementations of AVS, including shareware, may be
* subject to royalty fees to patent holders. Information regarding
* the AVS patent policy is available from the AVS Web site at
* http://www.avs.org.cn
*
* THIS IS NOT A GRANT OF PATENT RIGHTS - SEE THE AVS PATENT POLICY.
************************************************************************
*/

#include <float.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include "../include/amr_plus.h"
/*-----------------------------------------------------------------*
* Funtion init_decoder_lf *
* ~~~~~~~~~~~~~~~~~~~~~~~~ *
* *
* ->Initialization of variables for the decoder section. *
* *
*-----------------------------------------------------------------*/
void init_decoder_lf(Decoder_State_Plus *st)
{
int i;

/* Static vectors to zero */
set_zero(st->old_exc, PIT_MAX_MAX+L_INTERPOL); /* old excitation vector (>20ms) */
set_zero(st->old_synth, M);
set_zero(st->past_isfq, M);
set_zero(st->wovlp, L_OVLP);
#ifdef PW_UPDATE
set_zero(st->wovlp_ap2, 17);
set_zero(st->wovlp_ap3, 3);
#endif

/* Initialize the ISFs */
mvr2r((float *)isf_init, st->isfold, M);
for (i = 0; i < L_MEANBUF; i++) {
mvr2r((float*)isf_init, &amt;(st->isf_buf[i*M]), M);
}
/* Initialize the ISPs */
for (i=0; i<M-1; i++) {
st->ispold[i] = (float)cos(3.141592654*(float)(i+1)/(float)M);
}
st->ispold[M-1] = 0.045f;
st->prev_lpc_lost=0;
st->ovlp_size = 0;
st->old_T0 = 64;
st->old_T0_frac = 0;
st->seed_ace = 0;
st->mem_wsyn = 0.0;
st->seed_tcx = 21845;
st->wsyn_rms = 0.0;
st->past_gpit = 0.0;
st->past_gcode = 0.0;
st->pitch_tcx = L_DIV;
st->gc_threshold = 0.0f;

#ifdef PW_UPDATE
set_zero(st->mem_formant,M);
set_zero(st->mem_tilt,TILT_ORDER);
#endif
return;
}
extern float isfnew_uq[NB_DIV*M];
/*-----------------------------------------------------------------*
* Funtion decoder_lf *
* ~~~~~~~~~~~~~~~~~~ *
* ->Principle decoder routine (band 0 to 6400Hz). *
* *
*-----------------------------------------------------------------*/
void decoder_lf(
int mod[], /* (i) : mode for each 20ms frame (mode[4] */
int param[], /* (i) : parameters */
int nbits_AVQ[], /* (i) : for each frame (nbits_AVQ[4]) */
int codec_mode, /* (i) : AMR-WB+ mode (see cnst.h) */
int bad_frame[], /* (i) : for each frame (bad_frame[4]) */
float AqLF[], /* (o) : decoded coefficients (AdLF[16]) */
float exc[], /* (i/o): excitation[-(PIT_MAX_MAX+L_INTERPOL)..L_TCX-1] */
float fsynth[], /* (o) : decoded synthesis */
int pitch[], /* (o) : decoded pitch (pitch[16]) */
float pit_gain[], /* (o) : decoded pitch gain (pit_gain[16]) */
int pit_adj,
Decoder_State_Plus *st) /* i/o : decoder memory state */
{
/* LPC coefficients */
float ispnew[M];
float isfnew[M];
float Aq[(NB_SUBFR+1)*(M+1)]; /* A(z) for all subframes */
float *synth;
/* Scalars */
int i, k, mode, bfi, bfi_2nd_st, *prm;
/* LTP parameters for high band */
int T_out[4];
float p_out[4];
int len;
float tmp, stab_fac;
if(pit_adj == 0) {
len = L_DIV;
}
else {
i = (((pit_adj*PIT_MIN_12k8)+(FSCALE_DENOM/2))/FSCALE_DENOM)-PIT_MIN_12k8;
len = (PIT_MAX_12k8+(6*i)) + L_INTERPOL;
if (len < L_DIV) {
len = L_DIV;
}
}
/* initialize bass postfilter */
for (i=0; i<NB_SUBFR; i++) {
pitch[i] = L_SUBFR;
}
for (i=0; i<NB_SUBFR; i++) {
pit_gain[i] = 0.0;
}
/* Initialize pointers */
synth = fsynth;
mvr2r(st->old_synth, synth-M, M);
k = 0;
while (k < NB_DIV)
{
mode=mod[k];
bfi = bad_frame[k];
bfi_2nd_st = 0;
if ((mode == 2) &amt;&amt; (bad_frame[k+1] != 0)) {
bfi_2nd_st = (1+2+4+8+16);
}
if (mode == 3) {
if (bad_frame[k+1] != 0) {
bfi_2nd_st = 1;
}
if (bad_frame[k+2] != 0) {
bfi_2nd_st += (2+8);
}
if (bad_frame[k+3] != 0) {
bfi_2nd_st += (4+16);
}
}
/* set pointer to parameters */
prm = param + (k*DEC_NPRM_DIV);

/* ISF quantization */

dpisf_2s_46b_new(prm, isfnew, st->past_isfq, st->isfold, st->isf_buf, bfi, bfi_2nd_st, 1, &amt;st->bfi_count);

if (!bfi &amt;&amt; bfi_2nd_st == 0)
st->seed_tcx = (short)( (prm[0]*prm[1] + prm[4]*prm[5])*256);

prm += 7;
isf2isp(isfnew, ispnew, M);


/* 计算ISF稳定性，即旧的ISF与当前ISF的距离 */
tmp = 0.0f; /* ISF距离计数器 */
for (i=0; i<M-1; i++)
{
tmp += (isfnew[i]-st->isfold[i])*(isfnew[i]-st->isfold[i]);
}
stab_fac = (float)(tmp/400000.0f);/* 稳定性因子，将ISF距离归一化 */
/* 保存当前帧的ISF到历史缓冲区 */
if ((st->prev_lpc_lost != 0) &amt;&amt; (bfi == 0))
{
for (i=0; i<M-1; i++) {
if (ispnew[i] < st->ispold[i]) {
st->ispold[i] = ispnew[i];
}
}
}


/* - interpolate Ai in ISP domain (Aq) and save values for upper-band (Aq_lpc)
- decode other parameters according to mode
- set overlap size for next decoded frame (ovlp_size)
- set mode for upper-band decoder (mod[])*/
switch (mode) {
case 0:
case 1:
int_lpc_np1(st->ispold, ispnew, Aq, 4, M);
mvr2r(Aq, &amt;AqLF[(k*4)*(M+1)], 5*(M+1));

#ifdef NEW_TVC
if (mode == 0) /* 20-ms ACELP */
{
/* set global variables used in dec_ace() even for bfi=1*/
decoder_acelp(prm, Aq, L_DIV, codec_mode, bad_frame[k], &amt;exc[k*L_DIV],
&amt;synth[k*L_DIV], T_out, p_out, &amt;pitch[k*4], &amt;pit_gain[k*4],
pit_adj,stab_fac, st);
/* average integer pitch-lag for high band coding */
st->last_mode = 0;
} else {/* 20+2.5-ms TCX */
st->g_flg=k;
decoder_tcx(prm, &amt;nbits_AVQ[k], Aq, L_DIV, bad_frame+k,
&amt;exc[k*L_DIV], &amt;synth[k*L_DIV], st);
pre_ovlp( &amt;synth[k*L_DIV],k,st);
st->last_mode =1;
}
k++;
break;
case 2: /* 40+5-ms TCX */
int_lpc_np1(st->ispold, ispnew, Aq, 8, M);
mvr2r(Aq, &amt;AqLF[(k*4)*(M+1)], 9*(M+1));
st->g_flg=k;
decoder_tcx(prm, &amt;nbits_AVQ[k], Aq, 2*L_DIV, bad_frame+k,
&amt;exc[k*L_DIV], &amt;synth[k*L_DIV], st);
pre_ovlp( &amt;synth[k*L_DIV],k,st);
st->last_mode =2;
k+=2;
break;
case 3: /* 80+10-ms TCX */
int_lpc_np1(st->ispold, ispnew, Aq, 16, M);
mvr2r(Aq, &amt;AqLF[(k*4)*(M+1)], 17*(M+1));
st->g_flg=k;
decoder_tcx(prm, &amt;nbits_AVQ[k], Aq, 4*L_DIV, bad_frame,
&amt;exc[k*L_DIV], &amt;synth[k*L_DIV], st);
pre_ovlp( &amt;synth[k*L_DIV],k,st);
st->last_mode =3;
k+=4;
break;
default:
printf("decoder error: mode > 3!\n");
exit(0);
#else
if (mode == 0) /* 20-ms ACELP */
{
/* set global variables used in dec_ace() even for bfi=1*/
decoder_acelp(prm, Aq, L_DIV, codec_mode, bad_frame[k], &amt;exc[k*L_DIV],
&amt;synth[k*L_DIV], T_out, p_out, &amt;pitch[k*4], &amt;pit_gain[k*4],
pit_adj,stab_fac, st);
/* average integer pitch-lag for high band coding */
st->last_mode = 0;
} else {/* 20+2.5-ms TCX */
decoder_tcx(prm, &amt;nbits_AVQ[k], Aq, L_DIV, bad_frame+k,
&amt;exc[k*L_DIV], &amt;synth[k*L_DIV], st);
st->last_mode =1;
}
k++;
break;
case 2: /* 40+5-ms TCX */
int_lpc_np1(st->ispold, ispnew, Aq, 8, M);
mvr2r(Aq, &amt;AqLF[(k*4)*(M+1)], 9*(M+1));
decoder_tcx(prm, &amt;nbits_AVQ[k], Aq, 2*L_DIV, bad_frame+k,
&amt;exc[k*L_DIV], &amt;synth[k*L_DIV], st);
st->last_mode =2;
k+=2;
break;
case 3: /* 80+10-ms TCX */
int_lpc_np1(st->ispold, ispnew, Aq, 16, M);
mvr2r(Aq, &amt;AqLF[(k*4)*(M+1)], 17*(M+1));
decoder_tcx(prm, &amt;nbits_AVQ[k], Aq, 4*L_DIV, bad_frame,
&amt;exc[k*L_DIV], &amt;synth[k*L_DIV], st);
st->last_mode =3;
k+=4;
break;
default:
printf("decoder error: mode > 3!\n");
exit(0);
#endif
}
st->prev_lpc_lost = bfi;
/* update ispold[] and isfold[] for the next frame */
mvr2r(ispnew, st->ispold, M);
mvr2r(isfnew, st->isfold, M);
}
/*------ update signal for next superframe :
shift exc[], synth[] and synth_hf[] to the left by L_FRAME_PLUS -----*/
mvr2r(&amt;synth[L_FRAME_PLUS-M], st->old_synth, M);
/* output exc and synth */
mvr2r(synth, fsynth, L_FRAME_PLUS);
return;
}

#ifdef NEW_TVC
void pre_ovlp(
float gsynth[], /* (o) : decoded synthesis */
int flg,
Decoder_State_Plus *st) /* i/o : decoder memory state */
{

int i,n;
float *gwsynth;
n=st->ovlp_size;
if(st->gw_flg==1 ){
if(flg==0){
st->gw_flg=0;
}
else{
gwsynth=&amt;gsynth[-1];

for (i=0; i<n; i++) {
st->gw_synth[i] *= ((float)i)/((float)(n));
}
for (i=1; i<n; i++) {
gwsynth[1-i] *= ((float)i)/((float)(n));
gwsynth[1-i]+=st->gw_synth[n-i];
}

st->gw_flg=0;


}}
return;
}
#endif