381 lines
9.6 KiB
C
381 lines
9.6 KiB
C
/*
|
|
layer2.c: the layer 2 decoder, root of mpg123
|
|
|
|
copyright 1994-2021 by the mpg123 project - free software under the terms of the LGPL 2.1
|
|
see COPYING and AUTHORS files in distribution or http://mpg123.org
|
|
initially written by Michael Hipp
|
|
|
|
mpg123 started as mp2 decoder a long time ago...
|
|
part of this file is required for layer 1, too.
|
|
*/
|
|
|
|
|
|
#include "mpg123lib_intern.h"
|
|
|
|
#ifndef NO_LAYER2
|
|
#include "l2tables.h"
|
|
#endif
|
|
|
|
#include "getbits.h"
|
|
|
|
#ifndef NO_LAYER12 /* Stuff needed for layer I and II. */
|
|
|
|
#include "l12tabs.h"
|
|
|
|
#ifdef RUNTIME_TABLES
|
|
#include "init_layer12.h"
|
|
#endif
|
|
|
|
// The layer12_table is already in real format (fixed or float), just needs
|
|
// a little scaling in the MMX/SSE case.
|
|
|
|
void init_layer12_stuff(mpg123_handle *fr, real* (*init_table)(mpg123_handle *fr, real *table, int m))
|
|
{
|
|
int k;
|
|
real *table;
|
|
for(k=0;k<27;k++)
|
|
{
|
|
table = init_table(fr, fr->muls[k], k);
|
|
*table++ = 0.0;
|
|
}
|
|
}
|
|
|
|
real* init_layer12_table(mpg123_handle *fr, real *table, int m)
|
|
{
|
|
int i;
|
|
for(i=0;i<63;i++)
|
|
*table++ = layer12_table[m][i];
|
|
return table;
|
|
}
|
|
|
|
#ifdef OPT_MMXORSSE
|
|
real* init_layer12_table_mmx(mpg123_handle *fr, real *table, int m)
|
|
{
|
|
int i,j;
|
|
if(!fr->p.down_sample)
|
|
{
|
|
for(j=3,i=0;i<63;i++,j--)
|
|
*table++ = 16384 * layer12_table[m][i];
|
|
}
|
|
else
|
|
{
|
|
for(j=3,i=0;i<63;i++,j--)
|
|
*table++ = layer12_table[m][i];
|
|
}
|
|
return table;
|
|
}
|
|
#endif
|
|
|
|
#endif /* NO_LAYER12 */
|
|
|
|
/* The rest is the actual decoding of layer II data. */
|
|
|
|
#ifndef NO_LAYER2
|
|
|
|
static int II_step_one(unsigned int *bit_alloc,int *scale,mpg123_handle *fr)
|
|
{
|
|
int stereo = fr->stereo-1;
|
|
int sblimit = fr->II_sblimit;
|
|
int jsbound = fr->jsbound;
|
|
int sblimit2 = fr->II_sblimit<<stereo;
|
|
const struct al_table *alloc1 = fr->alloc;
|
|
int i;
|
|
unsigned int scfsi_buf[64];
|
|
unsigned int *scfsi,*bita;
|
|
int sc,step;
|
|
/* Count the bits needed for getbits_fast(). */
|
|
unsigned int needbits = 0;
|
|
unsigned int scale_bits[4] = { 18, 12, 6, 12 };
|
|
|
|
bita = bit_alloc;
|
|
if(stereo)
|
|
{
|
|
for(i=jsbound;i;i--,alloc1+=(1<<step))
|
|
{
|
|
step=alloc1->bits;
|
|
bita[0] = (char) getbits(fr, step);
|
|
bita[1] = (char) getbits(fr, step);
|
|
needbits += ((bita[0]?1:0)+(bita[1]?1:0))*2;
|
|
bita+=2;
|
|
}
|
|
for(i=sblimit-jsbound;i;i--,alloc1+=(1<<step))
|
|
{
|
|
step=alloc1->bits;
|
|
bita[0] = (char) getbits(fr, step);
|
|
bita[1] = bita[0];
|
|
needbits += (bita[0]?1:0)*2*2;
|
|
bita+=2;
|
|
}
|
|
bita = bit_alloc;
|
|
scfsi=scfsi_buf;
|
|
|
|
if(fr->bits_avail < needbits)
|
|
{
|
|
if(NOQUIET)
|
|
error2("need %u bits, have %li", needbits, fr->bits_avail);
|
|
return -1;
|
|
}
|
|
for(i=sblimit2;i;i--)
|
|
if(*bita++) *scfsi++ = (char) getbits_fast(fr, 2);
|
|
}
|
|
else /* mono */
|
|
{
|
|
for(i=sblimit;i;i--,alloc1+=(1<<step))
|
|
{
|
|
step=alloc1->bits;
|
|
*bita = (char) getbits(fr, step);
|
|
if(*bita)
|
|
needbits += 2;
|
|
++bita;
|
|
}
|
|
bita = bit_alloc;
|
|
scfsi=scfsi_buf;
|
|
if(fr->bits_avail < needbits)
|
|
{
|
|
if(NOQUIET)
|
|
error2("need %u bits, have %li", needbits, fr->bits_avail);
|
|
return -1;
|
|
}
|
|
for(i=sblimit;i;i--)
|
|
if(*bita++) *scfsi++ = (char) getbits_fast(fr, 2);
|
|
}
|
|
|
|
needbits = 0;
|
|
bita = bit_alloc;
|
|
scfsi=scfsi_buf;
|
|
for(i=sblimit2;i;--i)
|
|
if(*bita++)
|
|
needbits += scale_bits[*scfsi++];
|
|
if(fr->bits_avail < needbits)
|
|
{
|
|
if(NOQUIET)
|
|
error2("need %u bits, have %li", needbits, fr->bits_avail);
|
|
return -1;
|
|
}
|
|
|
|
bita = bit_alloc;
|
|
scfsi=scfsi_buf;
|
|
for(i=sblimit2;i;--i)
|
|
if(*bita++)
|
|
switch(*scfsi++)
|
|
{
|
|
case 0:
|
|
*scale++ = getbits_fast(fr, 6);
|
|
*scale++ = getbits_fast(fr, 6);
|
|
*scale++ = getbits_fast(fr, 6);
|
|
break;
|
|
case 1 :
|
|
*scale++ = sc = getbits_fast(fr, 6);
|
|
*scale++ = sc;
|
|
*scale++ = getbits_fast(fr, 6);
|
|
break;
|
|
case 2:
|
|
*scale++ = sc = getbits_fast(fr, 6);
|
|
*scale++ = sc;
|
|
*scale++ = sc;
|
|
break;
|
|
default: /* case 3 */
|
|
*scale++ = getbits_fast(fr, 6);
|
|
*scale++ = sc = getbits_fast(fr, 6);
|
|
*scale++ = sc;
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static void II_step_two(unsigned int *bit_alloc,real fraction[2][4][SBLIMIT],int *scale,mpg123_handle *fr,int x1)
|
|
{
|
|
int i,j,k,ba;
|
|
int stereo = fr->stereo;
|
|
int sblimit = fr->II_sblimit;
|
|
int jsbound = fr->jsbound;
|
|
const 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=fr->muls[k][scale[x1]];
|
|
fraction[j][0][i] = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15((int)getbits(fr, k) + d1), cm);
|
|
fraction[j][1][i] = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15((int)getbits(fr, k) + d1), cm);
|
|
fraction[j][2][i] = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15((int)getbits(fr, k) + d1), cm);
|
|
}
|
|
else
|
|
{
|
|
const unsigned char *table[] = { 0,0,0,grp_3tab,0,grp_5tab,0,0,0,grp_9tab };
|
|
unsigned int m=scale[x1];
|
|
unsigned int idx = (unsigned int) getbits(fr, k);
|
|
const unsigned char *tab = table[d1] + idx + idx + idx;
|
|
fraction[j][0][i] = REAL_SCALE_LAYER12(fr->muls[*tab++][m]);
|
|
fraction[j][1][i] = REAL_SCALE_LAYER12(fr->muls[*tab++][m]);
|
|
fraction[j][2][i] = REAL_SCALE_LAYER12(fr->muls[*tab][m]);
|
|
}
|
|
scale+=3;
|
|
}
|
|
else
|
|
fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = DOUBLE_TO_REAL(0.0);
|
|
if(fr->bits_avail < 0)
|
|
return; /* Caller checks that again. */
|
|
}
|
|
}
|
|
|
|
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=fr->muls[k][scale[x1+3]];
|
|
fraction[0][0][i] = DOUBLE_TO_REAL_15((int)getbits(fr, k) + d1);
|
|
fraction[0][1][i] = DOUBLE_TO_REAL_15((int)getbits(fr, k) + d1);
|
|
fraction[0][2][i] = DOUBLE_TO_REAL_15((int)getbits(fr, k) + d1);
|
|
fraction[1][0][i] = REAL_MUL_SCALE_LAYER12(fraction[0][0][i], cm);
|
|
fraction[1][1][i] = REAL_MUL_SCALE_LAYER12(fraction[0][1][i], cm);
|
|
fraction[1][2][i] = REAL_MUL_SCALE_LAYER12(fraction[0][2][i], cm);
|
|
cm=fr->muls[k][scale[x1]];
|
|
fraction[0][0][i] = REAL_MUL_SCALE_LAYER12(fraction[0][0][i], cm);
|
|
fraction[0][1][i] = REAL_MUL_SCALE_LAYER12(fraction[0][1][i], cm);
|
|
fraction[0][2][i] = REAL_MUL_SCALE_LAYER12(fraction[0][2][i], cm);
|
|
}
|
|
else
|
|
{
|
|
const unsigned char *table[] = { 0,0,0,grp_3tab,0,grp_5tab,0,0,0,grp_9tab };
|
|
unsigned int m1 = scale[x1];
|
|
unsigned int m2 = scale[x1+3];
|
|
unsigned int idx = (unsigned int) getbits(fr, k);
|
|
const unsigned char *tab = table[d1] + idx + idx + idx;
|
|
fraction[0][0][i] = REAL_SCALE_LAYER12(fr->muls[*tab][m1]); fraction[1][0][i] = REAL_SCALE_LAYER12(fr->muls[*tab++][m2]);
|
|
fraction[0][1][i] = REAL_SCALE_LAYER12(fr->muls[*tab][m1]); fraction[1][1][i] = REAL_SCALE_LAYER12(fr->muls[*tab++][m2]);
|
|
fraction[0][2][i] = REAL_SCALE_LAYER12(fr->muls[*tab][m1]); fraction[1][2][i] = REAL_SCALE_LAYER12(fr->muls[*tab][m2]);
|
|
}
|
|
scale+=6;
|
|
if(fr->bits_avail < 0)
|
|
return; /* Caller checks that again. */
|
|
}
|
|
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] = DOUBLE_TO_REAL(0.0);
|
|
}
|
|
/*
|
|
Historic comment...
|
|
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 !!
|
|
*/
|
|
}
|
|
|
|
if(sblimit > (fr->down_sample_sblimit) )
|
|
sblimit = fr->down_sample_sblimit;
|
|
|
|
for(i=sblimit;i<SBLIMIT;i++)
|
|
for (j=0;j<stereo;j++)
|
|
fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = DOUBLE_TO_REAL(0.0);
|
|
}
|
|
|
|
|
|
static void II_select_table(mpg123_handle *fr)
|
|
{
|
|
const 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;
|
|
const struct al_table *tables[5] = { alloc_0, alloc_1, alloc_2, alloc_3 , alloc_4 };
|
|
const int sblims[5] = { 27 , 30 , 8, 12 , 30 };
|
|
|
|
if(fr->sampling_frequency >= 3) /* Or equivalent: (fr->lsf == 1) */
|
|
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(mpg123_handle *fr)
|
|
{
|
|
int clip=0;
|
|
int i,j;
|
|
int stereo = fr->stereo;
|
|
/* pick_table clears unused subbands */
|
|
/* replacement for real fraction[2][4][SBLIMIT], needs alignment. */
|
|
real (*fraction)[4][SBLIMIT] = fr->layer2.fraction;
|
|
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(fr->jsbound > fr->II_sblimit)
|
|
{
|
|
fprintf(stderr, "Truncating stereo boundary to sideband limit.\n");
|
|
fr->jsbound=fr->II_sblimit;
|
|
}
|
|
|
|
/* TODO: What happens with mono mixing, actually? */
|
|
if(stereo == 1 || single == SINGLE_MIX) /* also, mix not really handled */
|
|
single = SINGLE_LEFT;
|
|
|
|
if(II_step_one(bit_alloc, scale, fr))
|
|
{
|
|
if(NOQUIET)
|
|
error("first step of layer I decoding failed");
|
|
return clip;
|
|
}
|
|
|
|
for(i=0;i<SCALE_BLOCK;i++)
|
|
{
|
|
II_step_two(bit_alloc,fraction,scale,fr,i>>2);
|
|
if(fr->bits_avail < 0)
|
|
{
|
|
if(NOQUIET)
|
|
error("missing bits in layer II step two");
|
|
return clip;
|
|
}
|
|
for(j=0;j<3;j++)
|
|
{
|
|
if(single != SINGLE_STEREO)
|
|
clip += (fr->synth_mono)(fraction[single][j], fr);
|
|
else
|
|
clip += (fr->synth_stereo)(fraction[0][j], fraction[1][j], fr);
|
|
}
|
|
}
|
|
|
|
return clip;
|
|
}
|
|
|
|
#endif /* NO_LAYER2 */
|