/**
** Supermodel
** A Sega Model 3 Arcade Emulator.
** Copyright 2011 Bart Trzynadlowski, Nik Henson
**
** This file is part of Supermodel.
**
** Supermodel is free software: you can redistribute it and/or modify it under
** the terms of the GNU General Public License as published by the Free
** Software Foundation, either version 3 of the License, or (at your option)
** any later version.
**
** Supermodel is distributed in the hope that it will be useful, but WITHOUT
** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
** FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
** more details.
**
** You should have received a copy of the GNU General Public License along
** with Supermodel. If not, see <http://www.gnu.org/licenses/>.
**/
/*
* misc2.cpp
*
* Amp library internal module.
*/
/* this file is a part of amp software, (C) tomislav uzelac 1996,1997
*/
/* misc2.c requantization, stereo processing, reordering(shortbl) and antialiasing butterflies
*
* misc.c was created by tomislav uzelac in May 1996, and was completely awful
* Created by: tomislav uzelac Dec 22 1996
* some more speed injected, cca. Jun 1 1997
*/
#include <math.h>
#include <string.h>
#include "amp.h"
#include "audio.h"
#include "getdata.h"
#include "huffman.h"
#define MISC2
#include "misc2.h"
#include "Supermodel.h"
/*
* fras == Formula for Requantization and All Scaling **************************
*/
static inline float fras_l(int sfb,int global_gain,int scalefac_scale,int scalefac,int preflag)
{
register int a,scale;
/*
if (scalefac_scale) scale=2;
else scale=1;
*/
scale=scalefac_scale+1;
a= global_gain -210 -(scalefac << scale);
if (preflag) a-=(t_pretab[sfb] << scale);
/* bugfix, Mar 13 97: shifting won't produce a legal result if we shift by more than 31
* since global_gain<256, this can only occur for (very) negative values of a.
*/
if (a < -127) return 0;
/* a minor change here as well, no point in abs() if we now that a<0
*/
if (a>=0) return tab[a&3]*(1 << (a>>2));
else return tabi[(-a)&3]/(1 << ((-a) >> 2));
}
static inline float fras_s(int global_gain,int subblock_gain,int scalefac_scale,int scalefac)
{
int a;
a=global_gain - 210 - (subblock_gain << 3);
if (scalefac_scale) a-= (scalefac << 2);
else a-= (scalefac << 1);
if (a < -127) return 0;
if (a>=0) return tab[a&3]*(1 << (a>>2));
else return tabi[(-a)&3]/(1 << ((-a) >> 2));
}
/* this should be faster than pow()
*/
static inline float fras2(int is,float a)
{
if (is > 0) return t_43[is]*a;
else return -t_43[-is]*a;
}
/*
* requantize_mono *************************************************************
*/
/* generally, the two channels do not have to be of the same block type - that's why we do two passes with requantize_mono.
* if ms or intensity stereo is enabled we do a single pass with requantize_ms because both channels are same block type
*/
void requantize_mono(int gr,int ch,struct SIDE_INFO *info,struct AUDIO_HEADER *header)
{
int l,i,sfb;
float a;
int global_gain=info->global_gain[gr][ch];
int scalefac_scale=info->scalefac_scale[gr][ch];
int sfreq=header->sampling_frequency;
no_of_imdcts[0]=no_of_imdcts[1]=32;
if (info->window_switching_flag[gr][ch] && info->block_type[gr][ch]==2)
if (info->mixed_block_flag[gr][ch]) {
/*
* requantize_mono - mixed blocks/long block part **********************
*/
int window,window_len,preflag=0; /* pretab is all zero in this low frequency area */
int scalefac=scalefac_l[gr][ch][0];
l=0;sfb=0;
a=fras_l(sfb,global_gain,scalefac_scale,scalefac,preflag);
while (l<36) {
xr[ch][0][l]=fras2(is[ch][l],a);
if (l==t_l[sfb]) {
scalefac=scalefac_l[gr][ch][++sfb];
a=fras_l(sfb,global_gain,scalefac_scale,scalefac,preflag);
}
l++;
}
/*
* requantize_mono - mixed blocks/short block part *********************
*/
sfb=3;
window_len=t_s[sfb]-t_s[sfb-1];
while (l<non_zero[ch]) {
for (window=0;window<3;window++) {
int scalefac=scalefac_s[gr][ch][sfb][window];
int subblock_gain=info->subblock_gain[gr][ch][window];
a=fras_s(global_gain,subblock_gain,scalefac_scale,scalefac);
for (i=0;i<window_len;i++) {
xr[ch][0][t_reorder[header->ID][sfreq][l]]=fras2(is[ch][l],a);
l++;
}
}
sfb++;
window_len=t_s[sfb]-t_s[sfb-1];
}
while (l<576) xr[ch][0][t_reorder[header->ID][sfreq][l++]]=0;
} else {
/*
* requantize mono - short blocks **************************************
*/
int window,window_len;
sfb=0; l=0;
window_len=t_s[0]+1;
while (l<non_zero[ch]) {
for (window=0;window<3;window++) {
int scalefac=scalefac_s[gr][ch][sfb][window];
int subblock_gain=info->subblock_gain[gr][ch][window];
float a=fras_s(global_gain,subblock_gain,scalefac_scale,scalefac);
for (i=0;i<window_len;i++) {
xr[ch][0][t_reorder[header->ID][sfreq][l]]=fras2(is[ch][l],a);
l++;
}
}
sfb++;
window_len=t_s[sfb]-t_s[sfb-1];
}
while (l<576) xr[ch][0][t_reorder[header->ID][sfreq][l++]]=0;
}
else {
/* long blocks */
int preflag=info->preflag[gr][ch];
int scalefac=scalefac_l[gr][ch][0];
sfb=0; l=0;
a=fras_l(sfb,global_gain,scalefac_scale,scalefac,preflag);
while (l<non_zero[ch]) {
xr[ch][0][l]=fras2(is[ch][l],a);
if (l==t_l[sfb]) {
scalefac=scalefac_l[gr][ch][++sfb];
a=fras_l(sfb,global_gain,scalefac_scale,scalefac,preflag);
}
l++;
}
while (l<576) xr[ch][0][l++]=0;
}
}
/*
* stereo stuff ****************************************************************
*/
static int find_isbound(int isbound[3],int gr,struct SIDE_INFO *info,struct AUDIO_HEADER *header)
{
int sfb,window,window_len,ms_flag,tmp,i;
isbound[0]=isbound[1]=isbound[2]=-1;
no_of_imdcts[0]=no_of_imdcts[1]=32;
if (header->mode_extension==1 || header->mode_extension==3) {
if (info->window_switching_flag[gr][0] && info->block_type[gr][0]==2) {
/* find that isbound!
*/
tmp=non_zero[1];
sfb=0; while ((3*t_s[sfb]+2) < tmp && sfb < 12) sfb++;
while ((isbound[0]<0 || isbound[1]<0 || isbound[2]<0) && !(info->mixed_block_flag[gr][0] && sfb<3) && sfb) {
for (window=0;window<3;window++) {
if (sfb==0) {
window_len=t_s[0]+1;
tmp=(window+1)*window_len - 1;
} else {
window_len=t_s[sfb]-t_s[sfb-1];
tmp=(3*t_s[sfb-1]+2) + (window+1)*window_len;
}
if (isbound[window] < 0)
for (i=0;i<window_len;i++)
if (is[1][tmp--] != 0) {
isbound[window]=t_s[sfb]+1;
break;
}
}
sfb--;
}
/* mixed block magic now...
*/
if (sfb==2 && info->mixed_block_flag[gr][0])
{
if (isbound[0]<0 && isbound[1]<0 && isbound[2]<0)
{
tmp=35;
while (is[1][tmp] == 0) tmp--;
sfb=0; while (t_l[sfb] < tmp && sfb < 21) sfb++;
isbound[0]=isbound[1]=isbound[2]=t_l[sfb]+1;
}
else for (window=0;window<3;window++)
if (isbound[window]<0) isbound[window]=36;
}
if (header->ID==1) isbound[0]=isbound[1]=isbound[2]=MAX(isbound[0],MAX(isbound[1],isbound[2]));
/* just how many imdcts?
*/
tmp=non_zero[0];
sfb=0; while ((3*t_s[sfb]+2) < tmp && sfb < 12) sfb++;
no_of_imdcts[0]=no_of_imdcts[1]=(t_s[sfb]-1)/6+1;
} else {
/* long blocks now
*/
tmp=non_zero[1];
while (is[1][tmp] == 0) tmp--;
sfb=0; while (t_l[sfb] < tmp && sfb < 21) sfb++;
isbound[0]=isbound[1]=isbound[2]=t_l[sfb]+1;
no_of_imdcts[0]=no_of_imdcts[1]=(non_zero[0]-1)/18+1;
}
if (header->mode_extension==1) ms_flag=0;
else ms_flag=1;
} else {
/* intensity stereo is, regretably, turned off
*/
ms_flag=1;
/* i really put a lot of work in this, but it still looks like shit (works, though)
*/
if (!info->window_switching_flag[gr][0] || (info->window_switching_flag[gr][0] && info->block_type[gr][0]!=2))
isbound[0]=isbound[1]=isbound[2]=(MAX(non_zero[0],non_zero[1]));
else isbound[0]=isbound[1]=isbound[2]=576;
if (info->window_switching_flag[gr][0] && info->block_type[gr][0]==2) {
/* should do for mixed blocks too, though i havent tested... */
tmp=(MAX(non_zero[0],non_zero[1]))/3;
sfb=0; while (t_s[sfb]<tmp && sfb<12) sfb++;
no_of_imdcts[0]=no_of_imdcts[1]=(t_s[sfb]-1)/6+1;
}
else no_of_imdcts[0]=no_of_imdcts[1]=(isbound[0]-1)/18+1;
}
return ms_flag;
}
static inline void stereo_s(int l,float a[2],int pos,int ms_flag,int is_pos,struct AUDIO_HEADER *header)
{
float ftmp,Mi,Si;
if (l>=576) return; /* brrr... */
if ((is_pos != IS_ILLEGAL) && (header->ID==1)) {
ftmp=fras2(is[0][l],a[0]);
xr[0][0][pos]=(1-t_is[is_pos])*ftmp;
xr[1][0][pos]=t_is[is_pos]*ftmp;
return;
}
if ((is_pos != IS_ILLEGAL) && (header->ID==0)) {
ftmp=fras2(is[0][l],a[0]);
if (is_pos&1) {
xr[0][0][pos]= t_is2[intensity_scale][(is_pos+1)>>1] * ftmp;
xr[1][0][pos]= ftmp;
} else {
xr[0][0][pos]= ftmp;
xr[1][0][pos]= t_is2[intensity_scale][is_pos>>1] * ftmp;
}
return;
}
if (ms_flag) {
Mi=fras2(is[0][l],a[0]);
Si=fras2(is[1][l],a[1]);
xr[0][0][pos]=(Mi+Si)*i_sq2;
xr[1][0][pos]=(Mi-Si)*i_sq2;
} else {
xr[0][0][pos]=fras2(is[0][l],a[0]);
xr[1][0][pos]=fras2(is[1][l],a[1]);
}
}
static inline void stereo_l(int l,float a[2],int ms_flag,int is_pos,struct AUDIO_HEADER *header)
{
float ftmp,Mi,Si;
if (l>=576) return;
/* new code by ???
*/
if (is_pos != IS_ILLEGAL) {
ftmp = fras2(is[0][l], a[0]);
if (header -> ID ==1) {
xr[0][0][l] = (1 - t_is[is_pos]) * ftmp;
xr[1][0][l] = t_is[is_pos] * ftmp;
return;
} else if (is_pos & 1) {
xr[0][0][l] = t_is2[intensity_scale][(is_pos + 1) >> 1] * ftmp;
xr[1][0][l] = ftmp;
} else {
xr[0][0][l] = ftmp;
xr[1][0][l] = t_is2[intensity_scale][is_pos >> 1] * ftmp;
}
return;
}
if (ms_flag) {
Mi=fras2(is[0][l],a[0]);
Si=fras2(is[1][l],a[1]);
xr[0][0][l]=(Mi+Si)*i_sq2;
xr[1][0][l]=(Mi-Si)*i_sq2;
} else {
xr[0][0][l]=fras2(is[0][l],a[0]);
xr[1][0][l]=fras2(is[1][l],a[1]);
}
}
/*
* requantize_ms ***************************************************************
*/
void requantize_ms(int gr,struct SIDE_INFO *info,struct AUDIO_HEADER *header)
{
int l,sfb,ms_flag,is_pos,i,ch;
int *global_gain,subblock_gain[2],*scalefac_scale,scalefac[2],isbound[3];
int sfreq=header->sampling_frequency;
int id = header->ID;
float a[2];
memset(a, 0, sizeof(a));
global_gain=info->global_gain[gr];
scalefac_scale=info->scalefac_scale[gr];
if (info->window_switching_flag[gr][0] && info->block_type[gr][0]==2)
if (info->mixed_block_flag[gr][0]) {
/*
* mixed blocks w/stereo processing - long block part ******************
*/
int window,window_len;
int preflag[2]={0,0};
ms_flag=find_isbound(isbound,gr,info,header);
sfb=0; l=0;
for (ch=0;ch<2;ch++) {
scalefac[ch]=scalefac_l[gr][ch][0];
a[ch]=fras_l(0,global_gain[ch],scalefac_scale[ch],scalefac[ch],preflag[ch]);
}
while (l<36) {
int is_pos;
if (l<isbound[0]) is_pos=IS_ILLEGAL;
else {
is_pos=scalefac[1];
if (id==1) /* MPEG1 */
{
if (is_pos==7) is_pos=IS_ILLEGAL;
}
else /* MPEG2 */
{
if (is_pos==is_max[sfb]) is_pos=IS_ILLEGAL;
}
}
stereo_l(l,a,ms_flag,is_pos,header);
if (l==t_l[sfb]) {
sfb++;
for (ch=0;ch<2;ch++) {
scalefac[ch]=scalefac_l[gr][ch][sfb];
a[ch]=fras_l(sfb,global_gain[ch],scalefac_scale[ch],scalefac[ch],preflag[ch]);
}
}
l++;
}
/*
* mixed blocks w/stereo processing - short block part *****************
*/
sfb=3;
window_len=t_s[sfb]-t_s[sfb-1];
while (l<(MAX(non_zero[0],non_zero[1]))) {
for (window=0;window<3;window++) {
subblock_gain[0]=info->subblock_gain[gr][0][window];
subblock_gain[1]=info->subblock_gain[gr][1][window];
scalefac[0]=scalefac_s[gr][0][sfb][window];
scalefac[1]=scalefac_s[gr][1][sfb][window];
if (t_s[sfb] < isbound[window]) {
is_pos=IS_ILLEGAL;
a[0]=fras_s(global_gain[0],subblock_gain[0],scalefac_scale[0],scalefac[0]);
a[1]=fras_s(global_gain[1],subblock_gain[1],scalefac_scale[1],scalefac[1]);
} else {
is_pos=scalefac[1];
if (id==1) /* MPEG1 */
{
if (is_pos==7) is_pos=IS_ILLEGAL;
}
else /* MPEG2 */
{
if (is_pos==is_max[sfb+6]) is_pos=IS_ILLEGAL;
}
a[0]=fras_s(global_gain[0],subblock_gain[0],scalefac_scale[0],scalefac[0]);
}
for (i=0;i<window_len;i++) {
stereo_s(l,a,t_reorder[id][sfreq][l],ms_flag,is_pos,header);
l++;
}
}
sfb++;
window_len=t_s[sfb]-t_s[sfb-1];
}
while (l<576) {
int reorder = t_reorder[id][sfreq][l++];
xr[0][0][reorder]=xr[1][0][reorder]=0;
}
} else {
/*
* requantize_ms - short blocks w/stereo processing ********************
*/
int window,window_len;
ms_flag=find_isbound(isbound,gr,info,header);
sfb=0; l=0;
window_len=t_s[0]+1;
while (l<(MAX(non_zero[0],non_zero[1]))) {
for (window=0;window<3;window++) {
subblock_gain[0]=info->subblock_gain[gr][0][window];
subblock_gain[1]=info->subblock_gain[gr][1][window];
scalefac[0]=scalefac_s[gr][0][sfb][window];
scalefac[1]=scalefac_s[gr][1][sfb][window];
if (t_s[sfb] < isbound[window]) {
is_pos=IS_ILLEGAL;
a[0]=fras_s(global_gain[0],subblock_gain[0],scalefac_scale[0],scalefac[0]);
a[1]=fras_s(global_gain[1],subblock_gain[1],scalefac_scale[1],scalefac[1]);
} else {
is_pos=scalefac[1];
if (id==1) /* MPEG1 */
{
if (is_pos==7) is_pos=IS_ILLEGAL;
}
else /* MPEG2 */
{
if (is_pos==is_max[sfb+6]) is_pos=IS_ILLEGAL;
}
a[0]=fras_s(global_gain[0],subblock_gain[0],scalefac_scale[0],scalefac[0]);
}
for (i=0;i<window_len;i++) {
stereo_s(l,a,t_reorder[id][sfreq][l],ms_flag,is_pos,header);
l++;
}
}
/* this won't do anymore
* window_len=-t_s[sfb]+t_s[++sfb];
*/
window_len = -t_s[sfb++];
window_len += t_s[sfb];
}
while (l<576) {
int reorder = t_reorder[id][sfreq][l++];
xr[0][0][reorder]=xr[1][0][reorder]=0;
}
}
else {
/*
* long blocks w/stereo processing *************************************
*/
int *preflag=info->preflag[gr];
ms_flag=find_isbound(isbound,gr,info,header);
sfb=0; l=0;
scalefac[0]=scalefac_l[gr][0][sfb];
a[0]=fras_l(sfb,global_gain[0],scalefac_scale[0],scalefac[0],preflag[0]);
scalefac[1]=scalefac_l[gr][1][sfb];
a[1]=fras_l(sfb,global_gain[1],scalefac_scale[1],scalefac[1],preflag[1]);
/* no intensity stereo part
*/
if (ms_flag)
while (l< isbound[0]) {
#if defined(PENTIUM_RDTSC)
unsigned int cnt4, cnt3, cnt2, cnt1;
static int min_cycles = 99999999;
__asm__(".byte 0x0f,0x31" : "=a" (cnt1), "=d" (cnt4));
#endif
{
register float Mi = fras2(is[0][l],a[0]);
register float Si = fras2(is[1][l],a[1]);
register float tmp = i_sq2;
xr[0][0][l]=(Mi+Si)*tmp;
xr[1][0][l]=(Mi-Si)*tmp;
}
#if defined(PENTIUM_RDTSC)
__asm__(".byte 0x0f,0x31" : "=a" (cnt2), "=d" (cnt4));
if (cnt2-cnt1 < min_cycles) {
min_cycles = cnt2-cnt1;
//printf("%d cycles\n", min_cycles);
}
#endif
if (l==t_l[sfb]) {
#if defined(PENTIUM_RDTSC2)
unsigned int cnt4, cnt2, cnt1;
static int min_cycles = 99999999;
__asm__(".byte 0x0f,0x31" : "=a" (cnt1), "=d" (cnt4));
#endif
sfb++;
scalefac[0]=scalefac_l[gr][0][sfb];
a[0]=fras_l(sfb,global_gain[0],scalefac_scale[0],scalefac[0],preflag[0]);
scalefac[1]=scalefac_l[gr][1][sfb];
a[1]=fras_l(sfb,global_gain[1],scalefac_scale[1],scalefac[1],preflag[1]);
#if defined(PENTIUM_RDTSC2)
__asm__(".byte 0x0f,0x31" : "=a" (cnt2), "=d" (cnt4));
if (cnt2-cnt1 < min_cycles) {
min_cycles = cnt2-cnt1;
//printf("%d cycles, sfb %d\n", min_cycles, sfb);
}
#endif
}
l++;
}
else
while (l< isbound[0]) {
xr[0][0][l]=fras2(is[0][l],a[0]);
xr[1][0][l]=fras2(is[1][l],a[1]);
if (l==t_l[sfb]) {
sfb++;
scalefac[0]=scalefac_l[gr][0][sfb];
a[0]=fras_l(sfb,global_gain[0],scalefac_scale[0],scalefac[0],preflag[0]);
scalefac[1]=scalefac_l[gr][1][sfb];
a[1]=fras_l(sfb,global_gain[1],scalefac_scale[1],scalefac[1],preflag[1]);
}
l++;
}
/* intensity stereo part
*/
while (l<(MAX(non_zero[0],non_zero[1]))) {
int is_pos=scalefac[1];
if (id==1) /* MPEG1 */
{
if (is_pos==7) is_pos=IS_ILLEGAL;
}
else /* MPEG2 */
{
if (is_pos==is_max[sfb]) is_pos=IS_ILLEGAL;
}
stereo_l(l,a,ms_flag,is_pos,header);
if (l==t_l[sfb]) {
sfb++;
scalefac[0]=scalefac_l[gr][0][sfb];
scalefac[1]=scalefac_l[gr][1][sfb];
a[0]=fras_l(sfb,global_gain[0],scalefac_scale[0],scalefac[0],preflag[0]);
}
l++;
}
while (l<576) {
xr[0][0][l]=0;
xr[1][0][l]=0;
l++;
}
}
}
/*
* requantize_downmix **********************************************************
*/
void requantize_downmix(int gr,struct SIDE_INFO *info,struct AUDIO_HEADER *header)
{
int l,sfb,ms_flag,i;
int *global_gain,subblock_gain[2],*scalefac_scale,scalefac[2];
int sfreq=header->sampling_frequency;
int id = header->ID;
float a[2];
/* first set some variables
*/
global_gain=info->global_gain[gr];
scalefac_scale=info->scalefac_scale[gr];
if (header->mode_extension==2 || header->mode_extension==3) ms_flag=1;
else ms_flag=0;
/* ... and then we're off for requantization
*/
if (info->window_switching_flag[gr][0] && info->block_type[gr][0]==2)
if (info->mixed_block_flag[gr][0]) {
ErrorLog("Internal error in MPEG decoder: mixed blocks encountered.");
} else {
int window,window_len;
int isbound[3];
int is_pos;
memset(isbound, 0, sizeof(isbound));
sfb=0; l=0; window_len=t_s[0]+1;
while (l<(MAX(non_zero[0],non_zero[1]))) {
for (window=0;window<3;window++) {
subblock_gain[0]=info->subblock_gain[gr][0][window];
subblock_gain[1]=info->subblock_gain[gr][1][window];
scalefac[0]=scalefac_s[gr][0][sfb][window];
is_pos=scalefac[1]=scalefac_s[gr][1][sfb][window];
if (t_s[sfb] < isbound[window]) {
a[0]=fras_s(global_gain[0],subblock_gain[0],scalefac_scale[0],scalefac[0]);
if (ms_flag) {
for (i=0;i<window_len;i++) {
register float Mi=fras2(is[0][l],a[0]);
xr[0][0][t_reorder[id][sfreq][l]]=Mi*i_sq2;
l++;
}
} else {
a[1]=fras_s(global_gain[1],subblock_gain[1],scalefac_scale[1],scalefac[1]);
for (i=0;i<window_len;i++) {
register float tmp1=fras2(is[0][l],a[0]);
register float tmp2=fras2(is[1][l],a[1]);
xr[0][0][t_reorder[id][sfreq][l]]=(tmp1+tmp2)*0.5f;
l++;
}
}
} else {
a[0]=fras_s(global_gain[0],subblock_gain[0],scalefac_scale[0],scalefac[0]);
for (i=0;i<window_len;i++) {
register float ftmp = fras2(is[0][l], a[0]);
if (id==0 && is_pos<is_max[sfb])
ftmp*=t_downmix[intensity_scale][(is_pos+1)>>1];
xr[0][0][t_reorder[id][sfreq][l]] = ftmp;
l++;
}
}
}
window_len = -t_s[sfb++];
window_len += t_s[sfb];
}
while (l<576) {
xr[0][0][l]=0;
l++;
}
}
else {
int *preflag=info->preflag[gr];
int isbound;
if (header->mode_extension==1 || header->mode_extension==3) {
int tmp=non_zero[1];
while (is[1][tmp] == 0) tmp--;
sfb=0; while (t_l[sfb] < tmp && sfb < 21) sfb++;
isbound=t_l[sfb]+1;
no_of_imdcts[0]=no_of_imdcts[1]=(non_zero[0]-1)/18+1;
} else {
isbound=(MAX(non_zero[0],non_zero[1]));
no_of_imdcts[0]=no_of_imdcts[1]=(isbound-1)/18+1;
}
sfb=0; l=0;
scalefac[0]=scalefac_l[gr][0][sfb];
a[0]=fras_l(sfb,global_gain[0],scalefac_scale[0],scalefac[0],preflag[0]);
scalefac[1]=scalefac_l[gr][1][sfb];
a[1]=fras_l(sfb,global_gain[1],scalefac_scale[1],scalefac[1],preflag[1]);
/* no intensity stereo part
*/
if (ms_flag)
while (l < isbound) {
register float Mi = fras2(is[0][l],a[0]);
register float tmp = i_sq2;
xr[0][0][l]=Mi*tmp;
if (l==t_l[sfb]) {
sfb++;
scalefac[0]=scalefac_l[gr][0][sfb];
a[0]=fras_l(sfb,global_gain[0],scalefac_scale[0],scalefac[0],preflag[0]);
scalefac[1]=scalefac_l[gr][1][sfb];
}
l++;
}
else
while (l < isbound) {
register float tmp1=fras2(is[0][l],a[0]);
register float tmp2=fras2(is[1][l],a[1]);
xr[0][0][l]=(tmp1+tmp2)*0.5f;
if (l==t_l[sfb]) {
sfb++;
scalefac[0]=scalefac_l[gr][0][sfb];
a[0]=fras_l(sfb,global_gain[0],scalefac_scale[0],scalefac[0],preflag[0]);
scalefac[1]=scalefac_l[gr][1][sfb];
a[1]=fras_l(sfb,global_gain[1],scalefac_scale[1],scalefac[1],preflag[1]);
}
l++;
}
/* intensity stereo part
*/
while (l<(MAX(non_zero[0],non_zero[1]))) {
int is_pos=scalefac[1];
register float ftmp=fras2(is[0][l], a[0]);
if (id==0 && is_pos<is_max[sfb]) {
ftmp*=t_downmix[intensity_scale][(is_pos+1)>>1];
}
xr[0][0][l] = ftmp;
if (l==t_l[sfb]) {
sfb++;
scalefac[0]=scalefac_l[gr][0][sfb];
a[0]=fras_l(sfb,global_gain[0],scalefac_scale[0],scalefac[0],preflag[0]);
scalefac[1]=scalefac_l[gr][1][sfb];
}
l++;
}
/* _always_ zero out everything else
*/
while (l<576) {
xr[0][0][l]=0;
l++;
}
}
}
/*
* antialiasing butterflies ****************************************************
*
*/
void alias_reduction(int ch)
{
unsigned int sb;
for (sb=1;sb<32;sb++) {
float *x = xr[ch][sb];
register float a, b;
a = x[0];
b = x[-1];
x[-1] = b * Cs[0] - a * Ca[0];
x[0] = a * Cs[0] + b * Ca[0];
a = x[1];
b = x[-2];
x[-2] = b * Cs[1] - a * Ca[1];
x[1] = a * Cs[1] + b * Ca[1];
a = x[2];
b = x[-3];
x[-3] = b * Cs[2] - a * Ca[2];
x[2] = a * Cs[2] + b * Ca[2];
a = x[3];
b = x[-4];
x[-4] = b * Cs[3] - a * Ca[3];
x[3] = a * Cs[3] + b * Ca[3];
a = x[4];
b = x[-5];
x[-5] = b * Cs[4] - a * Ca[4];
x[4] = a * Cs[4] + b * Ca[4];
a = x[5];
b = x[-6];
x[-6] = b * Cs[5] - a * Ca[5];
x[5] = a * Cs[5] + b * Ca[5];
a = x[6];
b = x[-7];
x[-7] = b * Cs[6] - a * Ca[6];
x[6] = a * Cs[6] + b * Ca[6];
a = x[7];
b = x[-8];
x[-8] = b * Cs[7] - a * Ca[7];
x[7] = a * Cs[7] + b * Ca[7];
}
}
/* calculating t_43 instead of having that big table in misc2.h
*/
void calculate_t43(void)
{
int i;
for (i=0;i<8192;i++)
t_43[i]=(float)pow((float)i,1.33333333333f);
}