301 lines
9.0 KiB
C
301 lines
9.0 KiB
C
|
/*
|
||
|
|
* Mpeg Layer-2 audio decoder
|
||
|
|
* --------------------------
|
||
|
|
* copyright (c) 1995 by Michael Hipp, All rights reserved. See also 'README'
|
||
|
|
* This file has been copied from mpglib.
|
||
|
|
*
|
||
|
|
* This library is free software; you can redistribute it and/or
|
||
|
|
* modify it under the terms of the GNU Lesser General Public
|
||
|
|
* License as published by the Free Software Foundation; either
|
||
|
|
* version 2.1 of the License, or (at your option) any later version.
|
||
|
|
*
|
||
|
|
* This library 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
|
||
|
|
* Lesser General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU Lesser General Public
|
||
|
|
* License along with this library; if not, write to the Free Software
|
||
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "mpg123.h"
|
||
|
|
#include "l2tables.h"
|
||
|
|
|
||
|
|
static int grp_3tab[32 * 3] = { 0, }; /* used: 27 */
|
||
|
|
static int grp_5tab[128 * 3] = { 0, }; /* used: 125 */
|
||
|
|
static int grp_9tab[1024 * 3] = { 0, }; /* used: 729 */
|
||
|
|
|
||
|
|
real muls[27][64]; /* also used by layer 1 */
|
||
|
|
|
||
|
|
void init_layer2(void)
|
||
|
|
{
|
||
|
|
static double mulmul[27] = {
|
||
|
|
0.0 , -2.0/3.0 , 2.0/3.0 ,
|
||
|
|
2.0/7.0 , 2.0/15.0 , 2.0/31.0, 2.0/63.0 , 2.0/127.0 , 2.0/255.0 ,
|
||
|
|
2.0/511.0 , 2.0/1023.0 , 2.0/2047.0 , 2.0/4095.0 , 2.0/8191.0 ,
|
||
|
|
2.0/16383.0 , 2.0/32767.0 , 2.0/65535.0 ,
|
||
|
|
-4.0/5.0 , -2.0/5.0 , 2.0/5.0, 4.0/5.0 ,
|
||
|
|
-8.0/9.0 , -4.0/9.0 , -2.0/9.0 , 2.0/9.0 , 4.0/9.0 , 8.0/9.0 };
|
||
|
|
static int base[3][9] = {
|
||
|
|
{ 1 , 0, 2 , } ,
|
||
|
|
{ 17, 18, 0 , 19, 20 , } ,
|
||
|
|
{ 21, 1, 22, 23, 0, 24, 25, 2, 26 } };
|
||
|
|
int i,j,k,l,len;
|
||
|
|
real *table;
|
||
|
|
static int tablen[3] = { 3 , 5 , 9 };
|
||
|
|
static int *itable,*tables[3] = { grp_3tab , grp_5tab , grp_9tab };
|
||
|
|
|
||
|
|
for(i=0;i<3;i++)
|
||
|
|
{
|
||
|
|
itable = tables[i];
|
||
|
|
len = tablen[i];
|
||
|
|
for(j=0;j<len;j++)
|
||
|
|
for(k=0;k<len;k++)
|
||
|
|
for(l=0;l<len;l++)
|
||
|
|
{
|
||
|
|
*itable++ = base[i][l];
|
||
|
|
*itable++ = base[i][k];
|
||
|
|
*itable++ = base[i][j];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
for(k=0;k<27;k++)
|
||
|
|
{
|
||
|
|
double m=mulmul[k];
|
||
|
|
table = muls[k];
|
||
|
|
for(j=3,i=0;i<63;i++,j--)
|
||
|
|
*table++ = m * pow(2.0,(double) j / 3.0);
|
||
|
|
*table++ = 0.0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
void II_step_one(unsigned int *bit_alloc,int *scale,struct frame *fr)
|
||
|
|
{
|
||
|
|
int stereo = fr->stereo-1;
|
||
|
|
int sblimit = fr->II_sblimit;
|
||
|
|
int jsbound = fr->jsbound;
|
||
|
|
int sblimit2 = fr->II_sblimit<<stereo;
|
||
|
|
struct al_table *alloc1 = fr->alloc;
|
||
|
|
int i;
|
||
|
|
static unsigned int scfsi_buf[64];
|
||
|
|
unsigned int *scfsi,*bita;
|
||
|
|
int sc,step;
|
||
|
|
|
||
|
|
bita = bit_alloc;
|
||
|
|
if(stereo)
|
||
|
|
{
|
||
|
|
for (i=jsbound;i;i--,alloc1+=(1<<step))
|
||
|
|
{
|
||
|
|
*bita++ = (char) getbits(step=alloc1->bits);
|
||
|
|
*bita++ = (char) getbits(step);
|
||
|
|
}
|
||
|
|
for (i=sblimit-jsbound;i;i--,alloc1+=(1<<step))
|
||
|
|
{
|
||
|
|
bita[0] = (char) getbits(step=alloc1->bits);
|
||
|
|
bita[1] = bita[0];
|
||
|
|
bita+=2;
|
||
|
|
}
|
||
|
|
bita = bit_alloc;
|
||
|
|
scfsi=scfsi_buf;
|
||
|
|
for (i=sblimit2;i;i--)
|
||
|
|
if (*bita++)
|
||
|
|
*scfsi++ = (char) getbits_fast(2);
|
||
|
|
}
|
||
|
|
else /* mono */
|
||
|
|
{
|
||
|
|
for (i=sblimit;i;i--,alloc1+=(1<<step))
|
||
|
|
*bita++ = (char) getbits(step=alloc1->bits);
|
||
|
|
bita = bit_alloc;
|
||
|
|
scfsi=scfsi_buf;
|
||
|
|
for (i=sblimit;i;i--)
|
||
|
|
if (*bita++)
|
||
|
|
*scfsi++ = (char) getbits_fast(2);
|
||
|
|
}
|
||
|
|
|
||
|
|
bita = bit_alloc;
|
||
|
|
scfsi=scfsi_buf;
|
||
|
|
for (i=sblimit2;i;i--)
|
||
|
|
if (*bita++)
|
||
|
|
switch (*scfsi++)
|
||
|
|
{
|
||
|
|
case 0:
|
||
|
|
*scale++ = getbits_fast(6);
|
||
|
|
*scale++ = getbits_fast(6);
|
||
|
|
*scale++ = getbits_fast(6);
|
||
|
|
break;
|
||
|
|
case 1 :
|
||
|
|
*scale++ = sc = getbits_fast(6);
|
||
|
|
*scale++ = sc;
|
||
|
|
*scale++ = getbits_fast(6);
|
||
|
|
break;
|
||
|
|
case 2:
|
||
|
|
*scale++ = sc = getbits_fast(6);
|
||
|
|
*scale++ = sc;
|
||
|
|
*scale++ = sc;
|
||
|
|
break;
|
||
|
|
default: /* case 3 */
|
||
|
|
*scale++ = getbits_fast(6);
|
||
|
|
*scale++ = sc = getbits_fast(6);
|
||
|
|
*scale++ = sc;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
void II_step_two(unsigned int *bit_alloc,real fraction[2][4][SBLIMIT],int *scale,struct frame *fr,int x1)
|
||
|
|
{
|
||
|
|
int i,j,k,ba;
|
||
|
|
int stereo = fr->stereo;
|
||
|
|
int sblimit = fr->II_sblimit;
|
||
|
|
int jsbound = fr->jsbound;
|
||
|
|
struct al_table *alloc2,*alloc1 = fr->alloc;
|
||
|
|
unsigned int *bita=bit_alloc;
|
||
|
|
int d1,step;
|
||
|
|
|
||
|
|
for (i=0;i<jsbound;i++,alloc1+=(1<<step))
|
||
|
|
{
|
||
|
|
step = alloc1->bits;
|
||
|
|
for (j=0;j<stereo;j++)
|
||
|
|
{
|
||
|
|
if ( (ba=*bita++) )
|
||
|
|
{
|
||
|
|
k=(alloc2 = alloc1+ba)->bits;
|
||
|
|
if( (d1=alloc2->d) < 0)
|
||
|
|
{
|
||
|
|
real cm=muls[k][scale[x1]];
|
||
|
|
fraction[j][0][i] = ((real) ((int)getbits(k) + d1)) * cm;
|
||
|
|
fraction[j][1][i] = ((real) ((int)getbits(k) + d1)) * cm;
|
||
|
|
fraction[j][2][i] = ((real) ((int)getbits(k) + d1)) * cm;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
static int *table[] = { 0,0,0,grp_3tab,0,grp_5tab,0,0,0,grp_9tab };
|
||
|
|
unsigned int idx,*tab,m=scale[x1];
|
||
|
|
idx = (unsigned int) getbits(k);
|
||
|
|
tab = (unsigned int *) (table[d1] + idx + idx + idx);
|
||
|
|
fraction[j][0][i] = muls[*tab++][m];
|
||
|
|
fraction[j][1][i] = muls[*tab++][m];
|
||
|
|
fraction[j][2][i] = muls[*tab][m];
|
||
|
|
}
|
||
|
|
scale+=3;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = 0.0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
for (i=jsbound;i<sblimit;i++,alloc1+=(1<<step))
|
||
|
|
{
|
||
|
|
step = alloc1->bits;
|
||
|
|
bita++; /* channel 1 and channel 2 bitalloc are the same */
|
||
|
|
if ( (ba=*bita++) )
|
||
|
|
{
|
||
|
|
k=(alloc2 = alloc1+ba)->bits;
|
||
|
|
if( (d1=alloc2->d) < 0)
|
||
|
|
{
|
||
|
|
real cm;
|
||
|
|
cm=muls[k][scale[x1+3]];
|
||
|
|
fraction[1][0][i] = (fraction[0][0][i] = (real) ((int)getbits(k) + d1) ) * cm;
|
||
|
|
fraction[1][1][i] = (fraction[0][1][i] = (real) ((int)getbits(k) + d1) ) * cm;
|
||
|
|
fraction[1][2][i] = (fraction[0][2][i] = (real) ((int)getbits(k) + d1) ) * cm;
|
||
|
|
cm=muls[k][scale[x1]];
|
||
|
|
fraction[0][0][i] *= cm; fraction[0][1][i] *= cm; fraction[0][2][i] *= cm;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
static int *table[] = { 0,0,0,grp_3tab,0,grp_5tab,0,0,0,grp_9tab };
|
||
|
|
unsigned int idx,*tab,m1,m2;
|
||
|
|
m1 = scale[x1]; m2 = scale[x1+3];
|
||
|
|
idx = (unsigned int) getbits(k);
|
||
|
|
tab = (unsigned int *) (table[d1] + idx + idx + idx);
|
||
|
|
fraction[0][0][i] = muls[*tab][m1]; fraction[1][0][i] = muls[*tab++][m2];
|
||
|
|
fraction[0][1][i] = muls[*tab][m1]; fraction[1][1][i] = muls[*tab++][m2];
|
||
|
|
fraction[0][2][i] = muls[*tab][m1]; fraction[1][2][i] = muls[*tab][m2];
|
||
|
|
}
|
||
|
|
scale+=6;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
fraction[0][0][i] = fraction[0][1][i] = fraction[0][2][i] =
|
||
|
|
fraction[1][0][i] = fraction[1][1][i] = fraction[1][2][i] = 0.0;
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
should we use individual scalefac for channel 2 or
|
||
|
|
is the current way the right one , where we just copy channel 1 to
|
||
|
|
channel 2 ??
|
||
|
|
The current 'strange' thing is, that we throw away the scalefac
|
||
|
|
values for the second channel ...!!
|
||
|
|
-> changed .. now we use the scalefac values of channel one !!
|
||
|
|
*/
|
||
|
|
}
|
||
|
|
|
||
|
|
for(i=sblimit;i<SBLIMIT;i++)
|
||
|
|
for (j=0;j<stereo;j++)
|
||
|
|
fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = 0.0;
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
static void II_select_table(struct frame *fr)
|
||
|
|
{
|
||
|
|
static int translate[3][2][16] =
|
||
|
|
{ { { 0,2,2,2,2,2,2,0,0,0,1,1,1,1,1,0 } ,
|
||
|
|
{ 0,2,2,0,0,0,1,1,1,1,1,1,1,1,1,0 } } ,
|
||
|
|
{ { 0,2,2,2,2,2,2,0,0,0,0,0,0,0,0,0 } ,
|
||
|
|
{ 0,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0 } } ,
|
||
|
|
{ { 0,3,3,3,3,3,3,0,0,0,1,1,1,1,1,0 } ,
|
||
|
|
{ 0,3,3,0,0,0,1,1,1,1,1,1,1,1,1,0 } } };
|
||
|
|
|
||
|
|
int table,sblim;
|
||
|
|
static struct al_table *tables[5] =
|
||
|
|
{ alloc_0, alloc_1, alloc_2, alloc_3 , alloc_4 };
|
||
|
|
static int sblims[5] = { 27 , 30 , 8, 12 , 30 };
|
||
|
|
|
||
|
|
if(fr->lsf)
|
||
|
|
table = 4;
|
||
|
|
else
|
||
|
|
table = translate[fr->sampling_frequency][2-fr->stereo][fr->bitrate_index];
|
||
|
|
sblim = sblims[table];
|
||
|
|
|
||
|
|
fr->alloc = tables[table];
|
||
|
|
fr->II_sblimit = sblim;
|
||
|
|
}
|
||
|
|
|
||
|
|
int do_layer2(struct frame *fr,unsigned char *pcm_sample,int *pcm_point)
|
||
|
|
{
|
||
|
|
int clip=0;
|
||
|
|
int i,j;
|
||
|
|
int stereo = fr->stereo;
|
||
|
|
real fraction[2][4][SBLIMIT]; /* pick_table clears unused subbands */
|
||
|
|
unsigned int bit_alloc[64];
|
||
|
|
int scale[192];
|
||
|
|
int single = fr->single;
|
||
|
|
|
||
|
|
II_select_table(fr);
|
||
|
|
fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ?
|
||
|
|
(fr->mode_ext<<2)+4 : fr->II_sblimit;
|
||
|
|
|
||
|
|
if(stereo == 1 || single == 3)
|
||
|
|
single = 0;
|
||
|
|
|
||
|
|
II_step_one(bit_alloc, scale, fr);
|
||
|
|
|
||
|
|
for (i=0;i<SCALE_BLOCK;i++)
|
||
|
|
{
|
||
|
|
II_step_two(bit_alloc,fraction,scale,fr,i>>2);
|
||
|
|
for (j=0;j<3;j++) {
|
||
|
|
if(single >= 0) {
|
||
|
|
clip += synth_1to1_mono(fraction[0][j],pcm_sample,pcm_point);
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
int p1 = *pcm_point;
|
||
|
|
clip += synth_1to1(fraction[0][j],0,pcm_sample,&p1);
|
||
|
|
clip += synth_1to1(fraction[1][j],1,pcm_sample,pcm_point);
|
||
|
|
}
|
||
|
|
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return clip;
|
||
|
|
}
|