| /* | |
| * 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; | |
| } |