diff options
Diffstat (limited to 'src/libmpg123/layer2.c')
-rw-r--r-- | src/libmpg123/layer2.c | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/src/libmpg123/layer2.c b/src/libmpg123/layer2.c new file mode 100644 index 0000000..e4de3c1 --- /dev/null +++ b/src/libmpg123/layer2.c @@ -0,0 +1,359 @@ +/* + layer2.c: the layer 2 decoder, root of mpg123 + + copyright 1994-2008 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 + + 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. */ + +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 */ + +static const 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 +}; + +void init_layer12(void) +{ + const 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; + const int tablen[3] = { 3 , 5 , 9 }; + int *itable; + int *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]; + } + } +} + +void init_layer12_stuff(mpg123_handle *fr, real* (*init_table)(mpg123_handle *fr, real *table, double m)) +{ + int k; + real *table; + for(k=0;k<27;k++) + { + table = init_table(fr, fr->muls[k], mulmul[k]); + *table++ = 0.0; + } +} + +real* init_layer12_table(mpg123_handle *fr, real *table, double m) +{ + int i,j; + for(j=3,i=0;i<63;i++,j--) + *table++ = DOUBLE_TO_REAL_SCALE_LAYER12(m * pow(2.0,(double) j / 3.0)); + + return table; +} + +#ifdef OPT_MMXORSSE +real* init_layer12_table_mmx(mpg123_handle *fr, real *table, double m) +{ + int i,j; + if(!fr->p.down_sample) + { + for(j=3,i=0;i<63;i++,j--) + *table++ = DOUBLE_TO_REAL(16384 * m * pow(2.0,(double) j / 3.0)); + } + else + { + for(j=3,i=0;i<63;i++,j--) + *table++ = DOUBLE_TO_REAL(m * pow(2.0,(double) j / 3.0)); + } + return table; +} +#endif + +#endif /* NO_LAYER12 */ + +/* The rest is the actual decoding of layer II data. */ + +#ifndef NO_LAYER2 + +void 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; + + bita = bit_alloc; + if(stereo) + { + for(i=jsbound;i;i--,alloc1+=(1<<step)) + { + step=alloc1->bits; + *bita++ = (char) getbits(fr, step); + *bita++ = (char) getbits(fr, step); + } + for(i=sblimit-jsbound;i;i--,alloc1+=(1<<step)) + { + step=alloc1->bits; + bita[0] = (char) getbits(fr, step); + bita[1] = bita[0]; + bita+=2; + } + bita = bit_alloc; + scfsi=scfsi_buf; + + 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); + } + bita = bit_alloc; + scfsi=scfsi_buf; + for(i=sblimit;i;i--) + if(*bita++) *scfsi++ = (char) getbits_fast(fr, 2); + } + + 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; + } +} + + +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 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(fr, k); + tab = (unsigned int *) (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); + } + } + + 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 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(fr, k); + tab = (unsigned int *) (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; + } + 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; + ALIGNED(16) 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(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; + + 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 != 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 */ |