/*  * Mpeg Layer-3 audio decoder  * -------------------------- * copyright (c) 1995,1996,1997 by Michael Hipp. * All rights reserved. See also 'README' */ #include <stdlib.h>#include "mpg123.h"#include "mpglib.h"#include "huffman.h"extern struct mpstr *gmp;#define MPEG1static real ispow[8207];static real aa_ca[8],aa_cs[8];static real COS1[12][6];static real win[4][36];static real win1[4][36];static real gainpow2[256+118+4];static real COS9[9];static real COS6_1,COS6_2;static real tfcos36[9];static real tfcos12[3];struct bandInfoStruct {  short longIdx[23];  short longDiff[22];  short shortIdx[14];  short shortDiff[13];};int longLimit[9][23];int shortLimit[9][14];struct bandInfoStruct bandInfo[9] = { /* MPEG 1.0 */ { {0,4,8,12,16,20,24,30,36,44,52,62,74, 90,110,134,162,196,238,288,342,418,576},   {4,4,4,4,4,4,6,6,8, 8,10,12,16,20,24,28,34,42,50,54, 76,158},   {0,4*3,8*3,12*3,16*3,22*3,30*3,40*3,52*3,66*3, 84*3,106*3,136*3,192*3},   {4,4,4,4,6,8,10,12,14,18,22,30,56} } , { {0,4,8,12,16,20,24,30,36,42,50,60,72, 88,106,128,156,190,230,276,330,384,576},   {4,4,4,4,4,4,6,6,6, 8,10,12,16,18,22,28,34,40,46,54, 54,192},   {0,4*3,8*3,12*3,16*3,22*3,28*3,38*3,50*3,64*3, 80*3,100*3,126*3,192*3},   {4,4,4,4,6,6,10,12,14,16,20,26,66} } , { {0,4,8,12,16,20,24,30,36,44,54,66,82,102,126,156,194,240,296,364,448,550,576} ,   {4,4,4,4,4,4,6,6,8,10,12,16,20,24,30,38,46,56,68,84,102, 26} ,   {0,4*3,8*3,12*3,16*3,22*3,30*3,42*3,58*3,78*3,104*3,138*3,180*3,192*3} ,   {4,4,4,4,6,8,12,16,20,26,34,42,12} }  ,/* MPEG 2.0 */ { {0,6,12,18,24,30,36,44,54,66,80,96,116,140,168,200,238,284,336,396,464,522,576},   {6,6,6,6,6,6,8,10,12,14,16,20,24,28,32,38,46,52,60,68,58,54 } ,   {0,4*3,8*3,12*3,18*3,24*3,32*3,42*3,56*3,74*3,100*3,132*3,174*3,192*3} ,   {4,4,4,6,6,8,10,14,18,26,32,42,18 } } , { {0,6,12,18,24,30,36,44,54,66,80,96,114,136,162,194,232,278,330,394,464,540,576},   {6,6,6,6,6,6,8,10,12,14,16,18,22,26,32,38,46,52,64,70,76,36 } ,   {0,4*3,8*3,12*3,18*3,26*3,36*3,48*3,62*3,80*3,104*3,136*3,180*3,192*3} ,   {4,4,4,6,8,10,12,14,18,24,32,44,12 } } , { {0,6,12,18,24,30,36,44,54,66,80,96,116,140,168,200,238,284,336,396,464,522,576},   {6,6,6,6,6,6,8,10,12,14,16,20,24,28,32,38,46,52,60,68,58,54 },   {0,4*3,8*3,12*3,18*3,26*3,36*3,48*3,62*3,80*3,104*3,134*3,174*3,192*3},   {4,4,4,6,8,10,12,14,18,24,30,40,18 } } ,/* MPEG 2.5 */ { {0,6,12,18,24,30,36,44,54,66,80,96,116,140,168,200,238,284,336,396,464,522,576} ,   {6,6,6,6,6,6,8,10,12,14,16,20,24,28,32,38,46,52,60,68,58,54},   {0,12,24,36,54,78,108,144,186,240,312,402,522,576},   {4,4,4,6,8,10,12,14,18,24,30,40,18} }, { {0,6,12,18,24,30,36,44,54,66,80,96,116,140,168,200,238,284,336,396,464,522,576} ,   {6,6,6,6,6,6,8,10,12,14,16,20,24,28,32,38,46,52,60,68,58,54},   {0,12,24,36,54,78,108,144,186,240,312,402,522,576},   {4,4,4,6,8,10,12,14,18,24,30,40,18} }, { {0,12,24,36,48,60,72,88,108,132,160,192,232,280,336,400,476,566,568,570,572,574,576},   {12,12,12,12,12,12,16,20,24,28,32,40,48,56,64,76,90,2,2,2,2,2},   {0, 24, 48, 72,108,156,216,288,372,480,486,492,498,576},   {8,8,8,12,16,20,24,28,36,2,2,2,26} } ,};static int mapbuf0[9][152];static int mapbuf1[9][156];static int mapbuf2[9][44];static int *map[9][3];static int *mapend[9][3];static unsigned int n_slen2[512]; /* MPEG 2.0 slen for 'normal' mode */static unsigned int i_slen2[256]; /* MPEG 2.0 slen for intensity stereo */static real tan1_1[16],tan2_1[16],tan1_2[16],tan2_2[16];static real pow1_1[2][16],pow2_1[2][16],pow1_2[2][16],pow2_2[2][16];/*  * init tables for layer-3  */void init_layer3(int down_sample_sblimit){  int i,j,k,l;  for(i=-256;i<118+4;i++)    gainpow2[i+256] = pow((double)2.0,-0.25 * (double) (i+210) );  for(i=0;i<8207;i++)    ispow[i] = pow((double)i,(double)4.0/3.0);  for (i=0;i<8;i++)  {    static double Ci[8]={-0.6,-0.535,-0.33,-0.185,-0.095,-0.041,-0.0142,-0.0037};    double sq=sqrt(1.0+Ci[i]*Ci[i]);    aa_cs[i] = 1.0/sq;    aa_ca[i] = Ci[i]/sq;  }  for(i=0;i<18;i++)  {    win[0][i]    = win[1][i]    = 0.5 * sin( M_PI / 72.0 * (double) (2*(i+0) +1) ) / cos ( M_PI * (double) (2*(i+0) +19) / 72.0 );    win[0][i+18] = win[3][i+18] = 0.5 * sin( M_PI / 72.0 * (double) (2*(i+18)+1) ) / cos ( M_PI * (double) (2*(i+18)+19) / 72.0 );  }  for(i=0;i<6;i++)  {    win[1][i+18] = 0.5 / cos ( M_PI * (double) (2*(i+18)+19) / 72.0 );    win[3][i+12] = 0.5 / cos ( M_PI * (double) (2*(i+12)+19) / 72.0 );    win[1][i+24] = 0.5 * sin( M_PI / 24.0 * (double) (2*i+13) ) / cos ( M_PI * (double) (2*(i+24)+19) / 72.0 );    win[1][i+30] = win[3][i] = 0.0;    win[3][i+6 ] = 0.5 * sin( M_PI / 24.0 * (double) (2*i+1) )  / cos ( M_PI * (double) (2*(i+6 )+19) / 72.0 );  }  for(i=0;i<9;i++)    COS9[i] = cos( M_PI / 18.0 * (double) i);  for(i=0;i<9;i++)    tfcos36[i] = 0.5 / cos ( M_PI * (double) (i*2+1) / 36.0 );  for(i=0;i<3;i++)    tfcos12[i] = 0.5 / cos ( M_PI * (double) (i*2+1) / 12.0 );  COS6_1 = cos( M_PI / 6.0 * (double) 1);  COS6_2 = cos( M_PI / 6.0 * (double) 2);  for(i=0;i<12;i++)  {    win[2][i]  = 0.5 * sin( M_PI / 24.0 * (double) (2*i+1) ) / cos ( M_PI * (double) (2*i+7) / 24.0 );    for(j=0;j<6;j++)      COS1[i][j] = cos( M_PI / 24.0 * (double) ((2*i+7)*(2*j+1)) );  }  for(j=0;j<4;j++) {    static int len[4] = { 36,36,12,36 };    for(i=0;i<len[j];i+=2)      win1[j][i] = + win[j][i];    for(i=1;i<len[j];i+=2)      win1[j][i] = - win[j][i];  }  for(i=0;i<16;i++)  {    double t = tan( (double) i * M_PI / 12.0 );    tan1_1[i] = t / (1.0+t);    tan2_1[i] = 1.0 / (1.0 + t);    tan1_2[i] = M_SQRT2 * t / (1.0+t);    tan2_2[i] = M_SQRT2 / (1.0 + t);    for(j=0;j<2;j++) {      double base = pow(2.0,-0.25*(j+1.0));      double p1=1.0,p2=1.0;      if(i > 0) {        if( i & 1 )          p1 = pow(base,(i+1.0)*0.5);        else          p2 = pow(base,i*0.5);      }      pow1_1[j][i] = p1;      pow2_1[j][i] = p2;      pow1_2[j][i] = M_SQRT2 * p1;      pow2_2[j][i] = M_SQRT2 * p2;    }  }  for(j=0;j<9;j++)  {   struct bandInfoStruct *bi = &bandInfo[j];   int *mp;   int cb,lwin;   short *bdf;   mp = map[j][0] = mapbuf0[j];   bdf = bi->longDiff;   for(i=0,cb = 0; cb < 8 ; cb++,i+=*bdf++) {     *mp++ = (*bdf) >> 1;     *mp++ = i;     *mp++ = 3;     *mp++ = cb;   }   bdf = bi->shortDiff+3;   for(cb=3;cb<13;cb++) {     int l = (*bdf++) >> 1;     for(lwin=0;lwin<3;lwin++) {       *mp++ = l;       *mp++ = i + lwin;       *mp++ = lwin;       *mp++ = cb;     }     i += 6*l;   }   mapend[j][0] = mp;   mp = map[j][1] = mapbuf1[j];   bdf = bi->shortDiff+0;   for(i=0,cb=0;cb<13;cb++) {     int l = (*bdf++) >> 1;     for(lwin=0;lwin<3;lwin++) {       *mp++ = l;       *mp++ = i + lwin;       *mp++ = lwin;       *mp++ = cb;     }     i += 6*l;   }   mapend[j][1] = mp;   mp = map[j][2] = mapbuf2[j];   bdf = bi->longDiff;   for(cb = 0; cb < 22 ; cb++) {     *mp++ = (*bdf++) >> 1;     *mp++ = cb;   }   mapend[j][2] = mp;  }  for(j=0;j<9;j++) {    for(i=0;i<23;i++) {      longLimit[j][i] = (bandInfo[j].longIdx[i] - 1 + 8) / 18 + 1;      if(longLimit[j][i] > (down_sample_sblimit) )        longLimit[j][i] = down_sample_sblimit;    }    for(i=0;i<14;i++) {      shortLimit[j][i] = (bandInfo[j].shortIdx[i] - 1) / 18 + 1;      if(shortLimit[j][i] > (down_sample_sblimit) )        shortLimit[j][i] = down_sample_sblimit;    }  }  for(i=0;i<5;i++) {    for(j=0;j<6;j++) {      for(k=0;k<6;k++) {        int n = k + j * 6 + i * 36;        i_slen2[n] = i|(j<<3)|(k<<6)|(3<<12);      }    }  }  for(i=0;i<4;i++) {    for(j=0;j<4;j++) {      for(k=0;k<4;k++) {        int n = k + j * 4 + i * 16;        i_slen2[n+180] = i|(j<<3)|(k<<6)|(4<<12);      }    }  }  for(i=0;i<4;i++) {    for(j=0;j<3;j++) {      int n = j + i * 3;      i_slen2[n+244] = i|(j<<3) | (5<<12);      n_slen2[n+500] = i|(j<<3) | (2<<12) | (1<<15);    }  }  for(i=0;i<5;i++) {    for(j=0;j<5;j++) {      for(k=0;k<4;k++) {        for(l=0;l<4;l++) {          int n = l + k * 4 + j * 16 + i * 80;          n_slen2[n] = i|(j<<3)|(k<<6)|(l<<9)|(0<<12);        }      }    }  }  for(i=0;i<5;i++) {    for(j=0;j<5;j++) {      for(k=0;k<4;k++) {        int n = k + j * 4 + i * 20;        n_slen2[n+400] = i|(j<<3)|(k<<6)|(1<<12);      }    }  }}/* * read additional side information */#ifdef MPEG1 static void III_get_side_info_1(struct III_sideinfo *si,int stereo, int ms_stereo,long sfreq,int single){   int ch, gr;   int powdiff = (single == 3) ? 4 : 0;   si->main_data_begin = getbits(9);   if (stereo == 1)     si->private_bits = getbits_fast(5);   else      si->private_bits = getbits_fast(3);   for (ch=0; ch<stereo; ch++) {       si->ch[ch].gr[0].scfsi = -1;       si->ch[ch].gr[1].scfsi = getbits_fast(4);   }   for (gr=0; gr<2; gr++)    {     for (ch=0; ch<stereo; ch++)      {       register struct gr_info_s *gr_info = &(si->ch[ch].gr[gr]);       gr_info->part2_3_length = getbits(12);       gr_info->big_values = getbits_fast(9);       if(gr_info->big_values > 288) {          fprintf(stderr,"big_values too large!\n");          gr_info->big_values = 288;       }       gr_info->pow2gain = gainpow2+256 - getbits_fast(8) + powdiff;       if(ms_stereo)         gr_info->pow2gain += 2;       gr_info->scalefac_compress = getbits_fast(4);/* window-switching flag == 1 for block_Type != 0 .. and block-type == 0 -> win-sw-flag = 0 */       if(get1bit())        {         int i;         gr_info->block_type = getbits_fast(2);         gr_info->mixed_block_flag = get1bit();         gr_info->table_select[0] = getbits_fast(5);         gr_info->table_select[1] = getbits_fast(5);         /*          * table_select[2] not needed, because there is no region2,          * but to satisfy some verifications tools we set it either.          */         gr_info->table_select[2] = 0;         for(i=0;i<3;i++)           gr_info->full_gain[i] = gr_info->pow2gain + (getbits_fast(3)<<3);         if(gr_info->block_type == 0) {           fprintf(stderr,"Blocktype == 0 and window-switching == 1 not allowed.\n");           exit(1);         }         /* region_count/start parameters are implicit in this case. */                gr_info->region1start = 36>>1;         gr_info->region2start = 576>>1;       }       else        {         int i,r0c,r1c;         for (i=0; i<3; i++)           gr_info->table_select[i] = getbits_fast(5);         r0c = getbits_fast(4);         r1c = getbits_fast(3);         gr_info->region1start = bandInfo[sfreq].longIdx[r0c+1] >> 1 ;         gr_info->region2start = bandInfo[sfreq].longIdx[r0c+1+r1c+1] >> 1;         gr_info->block_type = 0;         gr_info->mixed_block_flag = 0;       }       gr_info->preflag = get1bit();       gr_info->scalefac_scale = get1bit();       gr_info->count1table_select = get1bit();     }   }}#endif/* * Side Info for MPEG 2.0 / LSF */static void III_get_side_info_2(struct III_sideinfo *si,int stereo, int ms_stereo,long sfreq,int single){   int ch;   int powdiff = (single == 3) ? 4 : 0;   si->main_data_begin = getbits(8);   if (stereo == 1)     si->private_bits = get1bit();   else      si->private_bits = getbits_fast(2);   for (ch=0; ch<stereo; ch++)    {       register struct gr_info_s *gr_info = &(si->ch[ch].gr[0]);       gr_info->part2_3_length = getbits(12);       gr_info->big_values = getbits_fast(9);       if(gr_info->big_values > 288) {         fprintf(stderr,"big_values too large!\n");         gr_info->big_values = 288;       }       gr_info->pow2gain = gainpow2+256 - getbits_fast(8) + powdiff;       if(ms_stereo)         gr_info->pow2gain += 2;       gr_info->scalefac_compress = getbits(9);/* window-switching flag == 1 for block_Type != 0 .. and block-type == 0 -> win-sw-flag = 0 */       if(get1bit())        {         int i;         gr_info->block_type = getbits_fast(2);         gr_info->mixed_block_flag = get1bit();         gr_info->table_select[0] = getbits_fast(5);         gr_info->table_select[1] = getbits_fast(5);         /*          * table_select[2] not needed, because there is no region2,          * but to satisfy some verifications tools we set it either.          */         gr_info->table_select[2] = 0;         for(i=0;i<3;i++)           gr_info->full_gain[i] = gr_info->pow2gain + (getbits_fast(3)<<3);         if(gr_info->block_type == 0) {           fprintf(stderr,"Blocktype == 0 and window-switching == 1 not allowed.\n");           exit(1);         }         /* region_count/start parameters are implicit in this case. */       /* check this again! */         if(gr_info->block_type == 2)           gr_info->region1start = 36>>1;         else if(sfreq == 8)/* check this for 2.5 and sfreq=8 */           gr_info->region1start = 108>>1;         else           gr_info->region1start = 54>>1;         gr_info->region2start = 576>>1;       }       else        {         int i,r0c,r1c;         for (i=0; i<3; i++)           gr_info->table_select[i] = getbits_fast(5);         r0c = getbits_fast(4);         r1c = getbits_fast(3);         gr_info->region1start = bandInfo[sfreq].longIdx[r0c+1] >> 1 ;         gr_info->region2start = bandInfo[sfreq].longIdx[r0c+1+r1c+1] >> 1;         gr_info->block_type = 0;         gr_info->mixed_block_flag = 0;       }       gr_info->scalefac_scale = get1bit();       gr_info->count1table_select = get1bit();   }}/* * read scalefactors */#ifdef MPEG1static int III_get_scale_factors_1(int *scf,struct gr_info_s *gr_info){   static unsigned char slen[2][16] = {     {0, 0, 0, 0, 3, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4},     {0, 1, 2, 3, 0, 1, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3}   };   int numbits;   int num0 = slen[0][gr_info->scalefac_compress];   int num1 = slen[1][gr_info->scalefac_compress];    if (gr_info->block_type == 2)     {      int i=18;      numbits = (num0 + num1) * 18;      if (gr_info->mixed_block_flag) {         for (i=8;i;i--)           *scf++ = getbits_fast(num0);         i = 9;         numbits -= num0; /* num0 * 17 + num1 * 18 */      }      for (;i;i--)        *scf++ = getbits_fast(num0);      for (i = 18; i; i--)        *scf++ = getbits_fast(num1);      *scf++ = 0; *scf++ = 0; *scf++ = 0; /* short[13][0..2] = 0 */    }    else     {      int i;      int scfsi = gr_info->scfsi;      if(scfsi < 0) { /* scfsi < 0 => granule == 0 */         for(i=11;i;i--)           *scf++ = getbits_fast(num0);         for(i=10;i;i--)           *scf++ = getbits_fast(num1);         numbits = (num0 + num1) * 10 + num0;      }      else {        numbits = 0;        if(!(scfsi & 0x8)) {          for (i=6;i;i--)            *scf++ = getbits_fast(num0);          numbits += num0 * 6;        }        else {          *scf++ = 0; *scf++ = 0; *scf++ = 0;  /* set to ZERO necessary? */