forked from KolibriOS/kolibrios
156 lines
3.6 KiB
C
156 lines
3.6 KiB
C
/*
|
|
layer1.c: the layer 1 decoder
|
|
|
|
copyright 1995-2008 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
|
|
|
|
may have a few bugs after last optimization ...
|
|
*/
|
|
|
|
#include "mpg123lib_intern.h"
|
|
#include "getbits.h"
|
|
|
|
void I_step_one(unsigned int balloc[], unsigned int scale_index[2][SBLIMIT],mpg123_handle *fr)
|
|
{
|
|
unsigned int *ba=balloc;
|
|
unsigned int *sca = (unsigned int *) scale_index;
|
|
|
|
if(fr->stereo == 2)
|
|
{
|
|
int i;
|
|
int jsbound = fr->jsbound;
|
|
for(i=0;i<jsbound;i++)
|
|
{
|
|
*ba++ = getbits(fr, 4);
|
|
*ba++ = getbits(fr, 4);
|
|
}
|
|
for(i=jsbound;i<SBLIMIT;i++) *ba++ = getbits(fr, 4);
|
|
|
|
ba = balloc;
|
|
|
|
for(i=0;i<jsbound;i++)
|
|
{
|
|
if ((*ba++))
|
|
*sca++ = getbits(fr, 6);
|
|
if ((*ba++))
|
|
*sca++ = getbits(fr, 6);
|
|
}
|
|
for (i=jsbound;i<SBLIMIT;i++)
|
|
if((*ba++))
|
|
{
|
|
*sca++ = getbits(fr, 6);
|
|
*sca++ = getbits(fr, 6);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
int i;
|
|
for(i=0;i<SBLIMIT;i++) *ba++ = getbits(fr, 4);
|
|
|
|
ba = balloc;
|
|
for (i=0;i<SBLIMIT;i++)
|
|
if ((*ba++))
|
|
*sca++ = getbits(fr, 6);
|
|
}
|
|
}
|
|
|
|
void I_step_two(real fraction[2][SBLIMIT],unsigned int balloc[2*SBLIMIT], unsigned int scale_index[2][SBLIMIT],mpg123_handle *fr)
|
|
{
|
|
int i,n;
|
|
int smpb[2*SBLIMIT]; /* values: 0-65535 */
|
|
int *sample;
|
|
register unsigned int *ba;
|
|
register unsigned int *sca = (unsigned int *) scale_index;
|
|
|
|
if(fr->stereo == 2)
|
|
{
|
|
int jsbound = fr->jsbound;
|
|
register real *f0 = fraction[0];
|
|
register real *f1 = fraction[1];
|
|
ba = balloc;
|
|
for(sample=smpb,i=0;i<jsbound;i++)
|
|
{
|
|
if((n = *ba++)) *sample++ = getbits(fr, n+1);
|
|
|
|
if((n = *ba++)) *sample++ = getbits(fr, n+1);
|
|
}
|
|
for(i=jsbound;i<SBLIMIT;i++)
|
|
if((n = *ba++))
|
|
*sample++ = getbits(fr, n+1);
|
|
|
|
ba = balloc;
|
|
for(sample=smpb,i=0;i<jsbound;i++)
|
|
{
|
|
if((n=*ba++))
|
|
*f0++ = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15( ((-1)<<n) + (*sample++) + 1), fr->muls[n+1][*sca++]);
|
|
else *f0++ = DOUBLE_TO_REAL(0.0);
|
|
|
|
if((n=*ba++))
|
|
*f1++ = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15( ((-1)<<n) + (*sample++) + 1), fr->muls[n+1][*sca++]);
|
|
else *f1++ = DOUBLE_TO_REAL(0.0);
|
|
}
|
|
for(i=jsbound;i<SBLIMIT;i++)
|
|
{
|
|
if((n=*ba++))
|
|
{
|
|
real samp = DOUBLE_TO_REAL_15( ((-1)<<n) + (*sample++) + 1);
|
|
*f0++ = REAL_MUL_SCALE_LAYER12(samp, fr->muls[n+1][*sca++]);
|
|
*f1++ = REAL_MUL_SCALE_LAYER12(samp, fr->muls[n+1][*sca++]);
|
|
}
|
|
else *f0++ = *f1++ = DOUBLE_TO_REAL(0.0);
|
|
}
|
|
for(i=fr->down_sample_sblimit;i<32;i++)
|
|
fraction[0][i] = fraction[1][i] = 0.0;
|
|
}
|
|
else
|
|
{
|
|
register real *f0 = fraction[0];
|
|
ba = balloc;
|
|
for(sample=smpb,i=0;i<SBLIMIT;i++)
|
|
if ((n = *ba++))
|
|
*sample++ = getbits(fr, n+1);
|
|
|
|
ba = balloc;
|
|
for(sample=smpb,i=0;i<SBLIMIT;i++)
|
|
{
|
|
if((n=*ba++))
|
|
*f0++ = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15( ((-1)<<n) + (*sample++) + 1), fr->muls[n+1][*sca++]);
|
|
else *f0++ = DOUBLE_TO_REAL(0.0);
|
|
}
|
|
for(i=fr->down_sample_sblimit;i<32;i++)
|
|
fraction[0][i] = DOUBLE_TO_REAL(0.0);
|
|
}
|
|
}
|
|
|
|
int do_layer1(mpg123_handle *fr)
|
|
{
|
|
int clip=0;
|
|
int i,stereo = fr->stereo;
|
|
unsigned int balloc[2*SBLIMIT];
|
|
unsigned int scale_index[2][SBLIMIT];
|
|
ALIGNED(16) real fraction[2][SBLIMIT];
|
|
int single = fr->single;
|
|
|
|
fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ? (fr->mode_ext<<2)+4 : 32;
|
|
|
|
if(stereo == 1 || single == SINGLE_MIX) /* I don't see mixing handled here */
|
|
single = SINGLE_LEFT;
|
|
|
|
I_step_one(balloc,scale_index,fr);
|
|
|
|
for(i=0;i<SCALE_BLOCK;i++)
|
|
{
|
|
I_step_two(fraction,balloc,scale_index,fr);
|
|
|
|
if(single != SINGLE_STEREO)
|
|
clip += (fr->synth_mono)(fraction[single], fr);
|
|
else
|
|
clip += (fr->synth_stereo)(fraction[0], fraction[1], fr);
|
|
}
|
|
|
|
return clip;
|
|
}
|
|
|
|
|