layer3.c

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/*
 * Mpeg Layer-3 audio decoder
 * --------------------------
 * copyright (c) 1995,1996,1997 by Michael Hipp.
 * All rights reserved. See also 'README'
 */

/* $Id: layer3.c,v 1.49 2006/06/15 23:51:49 robert Exp $ */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <stdlib.h>
#include "common.h"
#include "huffman.h"
#include "lame.h"
#include "machine.h"
#include "encoder.h"
#include "lame-analysis.h"
#include "decode_i386.h"

#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif



static 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];
};

static int longLimit[9][23];
static int shortLimit[9][14];

const 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 } } ,
                                             /* docs: 332. mpg123: 330 */
 { {0,6,12,18,24,30,36,44,54,66,80,96,114,136,162,194,232,278,332,394,464,540,576},
   {6,6,6,6,6,6,8,10,12,14,16,18,22,26,32,38,46,54,62,70,76,36 } ,
   {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];

static unsigned int get1bit(PMPSTR mp)
{
  unsigned char rval;
  rval = *mp->wordpointer << mp->bitindex;

  mp->bitindex++;
  mp->wordpointer += (mp->bitindex>>3);
  mp->bitindex &= 7;

  return rval>>7;
}




/*
 * init tables for layer-3
 */
void init_layer3(int down_sample_sblimit)
{
  int i,j,k;

  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 = (struct bandInfoStruct *)&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++) {
        int l;
        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
 */

static void III_get_side_info_1(PMPSTR mp, 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(mp,9);
   if (stereo == 1)
     si->private_bits = getbits_fast(mp,5);
   else
     si->private_bits = getbits_fast(mp,3);

   for (ch=0; ch<stereo; ch++) {
       si->ch[ch].gr[0].scfsi = -1;
       si->ch[ch].gr[1].scfsi = getbits_fast(mp,4);
   }

   for (gr=0; gr<2; gr++)
   {
     for (ch=0; ch<stereo; ch++)
     {
       struct gr_info_s *gr_infos = &(si->ch[ch].gr[gr]);

       gr_infos->part2_3_length = getbits(mp,12);
       gr_infos->big_values = getbits_fast(mp,9);
       if(gr_infos->big_values > 288) {
          fprintf(stderr,"big_values too large! %i\n",gr_infos->big_values);
          gr_infos->big_values = 288;
       }
       {
         unsigned int qss = getbits_fast(mp,8);
         gr_infos->pow2gain = gainpow2+256 - qss + powdiff;
#ifndef NOANALYSIS
         if (mpg123_pinfo != NULL) {
           mpg123_pinfo->qss[gr][ch]=qss;
         }
#endif
       }
       if(ms_stereo)
         gr_infos->pow2gain += 2;
       gr_infos->scalefac_compress = getbits_fast(mp,4);
/* window-switching flag == 1 for block_Type != 0 .. and block-type == 0 -> win-sw-flag = 0 */
       if(get1bit(mp))
       {
         int i;
         gr_infos->block_type = getbits_fast(mp,2);
         gr_infos->mixed_block_flag = get1bit(mp);
         gr_infos->table_select[0] = getbits_fast(mp,5);
         gr_infos->table_select[1] = getbits_fast(mp,5);


         /*
          * table_select[2] not needed, because there is no region2,
          * but to satisfy some verifications tools we set it either.
          */
         gr_infos->table_select[2] = 0;
         for(i=0;i<3;i++) {
           unsigned int sbg = (getbits_fast(mp,3)<<3);
           gr_infos->full_gain[i] = gr_infos->pow2gain + sbg;
#ifndef NOANALYSIS
           if (mpg123_pinfo != NULL)
             mpg123_pinfo->sub_gain[gr][ch][i]=sbg/8;
#endif
         }

         if(gr_infos->block_type == 0) {
           fprintf(stderr,"Blocktype == 0 and window-switching == 1 not allowed.\n");
                   /* error seems to be very good recoverable, so don't exit */
           /* exit(1); */
         }
         /* region_count/start parameters are implicit in this case. */
         gr_infos->region1start = 36>>1;
         gr_infos->region2start = 576>>1;
       }
       else
       {
         int i,r0c,r1c;
         for (i=0; i<3; i++)
           gr_infos->table_select[i] = getbits_fast(mp,5);
         r0c = getbits_fast(mp,4);
         r1c = getbits_fast(mp,3);
         gr_infos->region1start = bandInfo[sfreq].longIdx[r0c+1] >> 1 ;
         gr_infos->region2start = bandInfo[sfreq].longIdx[r0c+1+r1c+1] >> 1;
         gr_infos->block_type = 0;
         gr_infos->mixed_block_flag = 0;
       }
       gr_infos->preflag = get1bit(mp);
       gr_infos->scalefac_scale = get1bit(mp);
       gr_infos->count1table_select = get1bit(mp);
     }
   }
}

/*
 * Side Info for MPEG 2.0 / LSF
 */
static void III_get_side_info_2(PMPSTR mp, 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(mp,8);

   if (stereo == 1)
     si->private_bits = get1bit(mp);
   else
     si->private_bits = getbits_fast(mp,2);

   for (ch=0; ch<stereo; ch++)
   {
       struct gr_info_s *gr_infos = &(si->ch[ch].gr[0]);
       unsigned int qss;

       gr_infos->part2_3_length = getbits(mp,12);
       gr_infos->big_values = getbits_fast(mp,9);
       if(gr_infos->big_values > 288) {
         fprintf(stderr,"big_values too large! %i\n",gr_infos->big_values);
         gr_infos->big_values = 288;
       }
       qss=getbits_fast(mp,8);
       gr_infos->pow2gain = gainpow2+256 - qss + powdiff;
#ifndef NOANALYSIS
       if (mpg123_pinfo!=NULL) {
           mpg123_pinfo->qss[0][ch]=qss;
       }
#endif


       if(ms_stereo)
         gr_infos->pow2gain += 2;
       gr_infos->scalefac_compress = getbits(mp,9);
/* window-switching flag == 1 for block_Type != 0 .. and block-type == 0 -> win-sw-flag = 0 */
       if(get1bit(mp))
       {
         int i;
         gr_infos->block_type = getbits_fast(mp,2);
         gr_infos->mixed_block_flag = get1bit(mp);
         gr_infos->table_select[0] = getbits_fast(mp,5);
         gr_infos->table_select[1] = getbits_fast(mp,5);
         /*
          * table_select[2] not needed, because there is no region2,
          * but to satisfy some verifications tools we set it either.
          */
         gr_infos->table_select[2] = 0;
         for(i=0;i<3;i++) {
           unsigned int sbg = (getbits_fast(mp,3)<<3);
           gr_infos->full_gain[i] = gr_infos->pow2gain + sbg;
#ifndef NOANALYSIS
           if (mpg123_pinfo!=NULL)
             mpg123_pinfo->sub_gain[0][ch][i]=sbg/8;
#endif

         }

         if(gr_infos->block_type == 0) {
           fprintf(stderr,"Blocktype == 0 and window-switching == 1 not allowed.\n");
                   /* error seems to be very good recoverable, so don't exit */
           /* exit(1); */
         }
         /* region_count/start parameters are implicit in this case. */
/* check this again! */
         if(gr_infos->block_type == 2) {
            if (sfreq == 8)
                gr_infos->region1start = 36;
            else
                gr_infos->region1start = 36>>1;
         }
         else if(sfreq == 8)
/* check this for 2.5 and sfreq=8 */
           gr_infos->region1start = 108>>1;
         else
           gr_infos->region1start = 54>>1;
         gr_infos->region2start = 576>>1;
       }
       else
       {
         int i,r0c,r1c;
         for (i=0; i<3; i++)
           gr_infos->table_select[i] = getbits_fast(mp,5);
         r0c = getbits_fast(mp,4);
         r1c = getbits_fast(mp,3);
         gr_infos->region1start = bandInfo[sfreq].longIdx[r0c+1] >> 1 ;
         gr_infos->region2start = bandInfo[sfreq].longIdx[r0c+1+r1c+1] >> 1;
         gr_infos->block_type = 0;
         gr_infos->mixed_block_flag = 0;
       }
       gr_infos->scalefac_scale = get1bit(mp);
       gr_infos->count1table_select = get1bit(mp);
   }
}

/*
 * read scalefactors
 */

static int
III_get_scale_factors_1(PMPSTR mp, int *scf,struct gr_info_s *gr_infos)
{
   static const 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_infos->scalefac_compress];
   int num1 = slen[1][gr_infos->scalefac_compress];

    if (gr_infos->block_type == 2)
    {
      int i=18;
      numbits = (num0 + num1) * 18;

      if (gr_infos->mixed_block_flag) {
         for (i=8;i;i--)
           *scf++ = getbits_fast(mp,num0);
         i = 9;
         numbits -= num0; /* num0 * 17 + num1 * 18 */
      }

      for (;i;i--)
        *scf++ = getbits_fast(mp,num0);
      for (i = 18; i; i--)
        *scf++ = getbits_fast(mp,num1);
      *scf++ = 0; *scf++ = 0; *scf++ = 0; /* short[13][0..2] = 0 */
    }
    else
    {
      int i;
      int scfsi = gr_infos->scfsi;

      if(scfsi < 0) { /* scfsi < 0 => granule == 0 */
         for(i=11;i;i--)
           *scf++ = getbits_fast(mp,num0);
         for(i=10;i;i--)
           *scf++ = getbits_fast(mp,num1);
         numbits = (num0 + num1) * 10 + num0;
      }
      else {
        numbits = 0;
        if(!(scfsi & 0x8)) {
          for (i=6;i;i--)
            *scf++ = getbits_fast(mp,num0);
          numbits += num0 * 6;
        }
        else {
          scf += 6;
        }

        if(!(scfsi & 0x4)) {
          for (i=5;i;i--)
            *scf++ = getbits_fast(mp,num0);
          numbits += num0 * 5;
        }
        else {
          scf += 5;
        }

        if(!(scfsi & 0x2)) {
          for(i=5;i;i--)
            *scf++ = getbits_fast(mp,num1);
          numbits += num1 * 5;
        }
        else {
          scf += 5;
        }

        if(!(scfsi & 0x1)) {
          for (i=5;i;i--)
            *scf++ = getbits_fast(mp,num1);
          numbits += num1 * 5;
        }
        else {
          scf += 5;
        }
      }

      *scf++ = 0;  /* no l[21] in original sources */
    }
    return numbits;
}


static int
III_get_scale_factors_2(PMPSTR mp, int *scf,struct gr_info_s *gr_infos,int i_stereo)
{
  unsigned char *pnt;
  int i,j;
  unsigned int slen;
  int n = 0;
  int numbits = 0;

  static const unsigned char stab[3][6][4] = {
   { { 6, 5, 5,5 } , { 6, 5, 7,3 } , { 11,10,0,0} ,
     { 7, 7, 7,0 } , { 6, 6, 6,3 } , {  8, 8,5,0} } ,
   { { 9, 9, 9,9 } , { 9, 9,12,6 } , { 18,18,0,0} ,
     {12,12,12,0 } , {12, 9, 9,6 } , { 15,12,9,0} } ,
   { { 6, 9, 9,9 } , { 6, 9,12,6 } , { 15,18,0,0} ,
     { 6,15,12,0 } , { 6,12, 9,6 } , {  6,18,9,0} } };

  if(i_stereo) /* i_stereo AND second channel -> do_layer3() checks this */
    slen = i_slen2[gr_infos->scalefac_compress>>1];
  else
    slen = n_slen2[gr_infos->scalefac_compress];

  gr_infos->preflag = (slen>>15) & 0x1;

  n = 0;
  if( gr_infos->block_type == 2 ) {
    n++;
    if(gr_infos->mixed_block_flag)
      n++;
  }

  pnt = (unsigned char *)stab[n][(slen>>12)&0x7];

  for(i=0;i<4;i++) {
    int num = slen & 0x7;
    slen >>= 3;
    if(num) {
      for(j=0;j<(int)(pnt[i]);j++)
        *scf++ = getbits_fast(mp,num);
      numbits += pnt[i] * num;
    }
    else {
      for(j=0;j<(int)(pnt[i]);j++)
        *scf++ = 0;
    }
  }

  n = (n << 1) + 1;
  for(i=0;i<n;i++)
    *scf++ = 0;

  return numbits;
}

static const int pretab1 [22] = {0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,2,2,3,3,3,2,0}; /* char enough ? */
static const int pretab2 [22] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

/*
 * don't forget to apply the same changes to III_dequantize_sample_ms() !!!
 */
static int III_dequantize_sample(PMPSTR mp, real xr[SBLIMIT][SSLIMIT],int *scf,
   struct gr_info_s *gr_infos,int sfreq,int part2bits)
{
  int shift = 1 + gr_infos->scalefac_scale;
  real *xrpnt = (real *) xr;
  int l[3],l3;
  int part2remain = gr_infos->part2_3_length - part2bits;
  int *me;

  {
    int i;

    for(i=(&xr[SBLIMIT][0]-xrpnt)>>1;i>0;i--) {
      *xrpnt++ = 0.0;
      *xrpnt++ = 0.0;
    }

    xrpnt = (real *) xr;
  }

  {
    int bv       = gr_infos->big_values;
    int region1  = gr_infos->region1start;
    int region2  = gr_infos->region2start;

    l3 = ((576>>1)-bv)>>1;
/*
 * we may lose the 'odd' bit here !!
 * check this later again
 */
    if(bv <= region1) {
      l[0] = bv; l[1] = 0; l[2] = 0;
    }
    else {
      l[0] = region1;
      if(bv <= region2) {
        l[1] = bv - l[0];  l[2] = 0;
      }
      else {
        l[1] = region2 - l[0]; l[2] = bv - region2;
      }
    }
  }
  /* MDH crash fix */
  {
      int i;
      for (i = 0; i < 3; i++) {
          if (l[i] < 0) {
              fprintf(stderr, "mpg123: Bogus region length (%d)\n", l[i]);
              l[i] = 0;
          }
      }
  }
  /* end MDH crash fix */

  if(gr_infos->block_type == 2) {
    /*
     * decoding with short or mixed mode BandIndex table
     */
    int i,max[4];
    int step=0,lwin=0,cb=0;
    real v = 0.0;
    int *m,mc;

    if(gr_infos->mixed_block_flag) {
      max[3] = -1;
      max[0] = max[1] = max[2] = 2;
      m = map[sfreq][0];
      me = mapend[sfreq][0];
    }
    else {
      max[0] = max[1] = max[2] = max[3] = -1;
      /* max[3] not really needed in this case */
      m = map[sfreq][1];
      me = mapend[sfreq][1];
    }

    mc = 0;
    for(i=0;i<2;i++) {
      int lp = l[i];
      struct newhuff *h = (struct newhuff *)(ht+gr_infos->table_select[i]);
      for(;lp;lp--,mc--) {
        int x,y;
        if( (!mc) ) {
          mc = *m++;
          xrpnt = ((real *) xr) + (*m++);
          lwin = *m++;
          cb = *m++;
          if(lwin == 3) {
            v = gr_infos->pow2gain[(*scf++) << shift];
            step = 1;
          }
          else {
            v = gr_infos->full_gain[lwin][(*scf++) << shift];
            step = 3;
          }
        }
        {
          short *val = (short *)h->table;
          while((y=*val++)<0) {
            if (get1bit(mp))
              val -= y;
            part2remain--;
          }
          x = y >> 4;
          y &= 0xf;
        }
        if(x == 15) {
          max[lwin] = cb;
          part2remain -= h->linbits+1;
          x += getbits(mp,(int)h->linbits);
          if(get1bit(mp))
            *xrpnt = -ispow[x] * v;
          else
            *xrpnt =  ispow[x] * v;
        }
        else if(x) {
          max[lwin] = cb;
          if(get1bit(mp))
            *xrpnt = -ispow[x] * v;
          else
            *xrpnt =  ispow[x] * v;
          part2remain--;
        }
        else
          *xrpnt = 0.0;
        xrpnt += step;
        if(y == 15) {
          max[lwin] = cb;
          part2remain -= h->linbits+1;
          y += getbits(mp,(int)h->linbits);
          if(get1bit(mp))
            *xrpnt = -ispow[y] * v;
          else
            *xrpnt =  ispow[y] * v;
        }
        else if(y) {
          max[lwin] = cb;
          if(get1bit(mp))
            *xrpnt = -ispow[y] * v;
          else
            *xrpnt =  ispow[y] * v;
          part2remain--;
        }
        else
          *xrpnt = 0.0;
        xrpnt += step;
      }
    }
    for(;l3 && (part2remain > 0);l3--) {
      struct newhuff *h = (struct newhuff *)(htc+gr_infos->count1table_select);
      short *val = (short *)h->table,a;

      while((a=*val++)<0) {
        part2remain--;
        if(part2remain < 0) {
          part2remain++;
          a = 0;
          break;
        }
        if (get1bit(mp))
          val -= a;
      }
      for(i=0;i<4;i++) {
        if(!(i & 1)) {
          if(!mc) {
            mc = *m++;
            xrpnt = ((real *) xr) + (*m++);
            lwin = *m++;
            cb = *m++;
            if(lwin == 3) {
              v = gr_infos->pow2gain[(*scf++) << shift];
              step = 1;
            }
            else {
              v = gr_infos->full_gain[lwin][(*scf++) << shift];
              step = 3;
            }
          }
          mc--;
        }
        if( (a & (0x8>>i)) ) {
          max[lwin] = cb;
          part2remain--;
          if(part2remain < 0) {
            part2remain++;
            break;
          }
          if(get1bit(mp))
            *xrpnt = -v;
          else
            *xrpnt = v;
        }
        else
          *xrpnt = 0.0;
        xrpnt += step;
      }
    }

    while( m < me ) {
      if(!mc) {
        mc = *m++;
        xrpnt = ((real *) xr) + *m++;
        if( (*m++) == 3)
          step = 1;
        else
          step = 3;
        m++; /* cb */
      }
      mc--;
      *xrpnt = 0.0;
      xrpnt += step;
      *xrpnt = 0.0;
      xrpnt += step;
/* we could add a little opt. here:
 * if we finished a band for window 3 or a long band
 * further bands could copied in a simple loop without a
 * special 'map' decoding
 */
    }

    gr_infos->maxband[0] = max[0]+1;
    gr_infos->maxband[1] = max[1]+1;
    gr_infos->maxband[2] = max[2]+1;
    gr_infos->maxbandl = max[3]+1;

    {
      int rmax = max[0] > max[1] ? max[0] : max[1];
      rmax = (rmax > max[2] ? rmax : max[2]) + 1;
      gr_infos->maxb = rmax ? shortLimit[sfreq][rmax] : longLimit[sfreq][max[3]+1];
    }

  }
  else {
        /*
     * decoding with 'long' BandIndex table (block_type != 2)
     */
    int *pretab = (int *)(gr_infos->preflag ? pretab1 : pretab2);
    int i,max = -1;
    int cb = 0;
    int *m = map[sfreq][2];
    real v = 0.0;
    int mc = 0;

        /*
     * long hash table values
     */
    for(i=0;i<3;i++) {
      int lp = l[i];
      struct newhuff *h = (struct newhuff *)(ht+gr_infos->table_select[i]);

      for(;lp;lp--,mc--) {
        int x,y;

        if(!mc) {
          mc = *m++;
          v = gr_infos->pow2gain[((*scf++) + (*pretab++)) << shift];
          cb = *m++;
        }
        {
          short *val = (short *)h->table;
          while((y=*val++)<0) {
            if (get1bit(mp))
              val -= y;
            part2remain--;
          }
          x = y >> 4;
          y &= 0xf;
        }
        if (x == 15) {
          max = cb;
          part2remain -= h->linbits+1;
          x += getbits(mp,(int)h->linbits);
          if(get1bit(mp))
            *xrpnt++ = -ispow[x] * v;
          else
            *xrpnt++ =  ispow[x] * v;
        }
        else if(x) {
          max = cb;
          if(get1bit(mp))
            *xrpnt++ = -ispow[x] * v;
          else
            *xrpnt++ =  ispow[x] * v;
          part2remain--;
        }
        else
          *xrpnt++ = 0.0;

        if (y == 15) {
          max = cb;
          part2remain -= h->linbits+1;
          y += getbits(mp,(int)h->linbits);
          if(get1bit(mp))
            *xrpnt++ = -ispow[y] * v;
          else
            *xrpnt++ =  ispow[y] * v;
        }
        else if(y) {
          max = cb;
          if(get1bit(mp))
            *xrpnt++ = -ispow[y] * v;
          else
            *xrpnt++ =  ispow[y] * v;
          part2remain--;
        }
        else
          *xrpnt++ = 0.0;
      }
    }

        /*
     * short (count1table) values
     */
    for(;l3 && (part2remain > 0);l3--) {
      struct newhuff *h = (struct newhuff *)(htc+gr_infos->count1table_select);
      short *val = (short *)h->table,a;

      while((a=*val++)<0) {
        part2remain--;
        if(part2remain < 0) {
          part2remain++;
          a = 0;
          break;
        }
        if (get1bit(mp))
          val -= a;
      }
      for(i=0;i<4;i++) {
        if(!(i & 1)) {
          if(!mc) {
            mc = *m++;
            cb = *m++;
            v = gr_infos->pow2gain[((*scf++) + (*pretab++)) << shift];
          }
          mc--;
        }
        if ( (a & (0x8>>i)) ) {
          max = cb;
          part2remain--;
          if(part2remain < 0) {
            part2remain++;
            break;
          }
          if(get1bit(mp))
            *xrpnt++ = -v;
          else
            *xrpnt++ = v;
        }
        else
          *xrpnt++ = 0.0;
      }
    }

        /*
     * zero part
     */
    for(i=(&xr[SBLIMIT][0]-xrpnt)>>1;i;i--) {
      *xrpnt++ = 0.0;
      *xrpnt++ = 0.0;
    }

    gr_infos->maxbandl = max+1;
    gr_infos->maxb = longLimit[sfreq][gr_infos->maxbandl];
  }

  while( part2remain > 16 ) {
    getbits(mp,16); /* Dismiss stuffing Bits */
    part2remain -= 16;
  }
  if(part2remain > 0)
    getbits(mp,part2remain);
  else if(part2remain < 0) {
    fprintf(stderr,"mpg123: Can't rewind stream by %d bits!\n",-part2remain);
    return 1; /* -> error */
  }
  return 0;
}


/*
 * III_stereo: calculate real channel values for Joint-I-Stereo-mode
 */
static void III_i_stereo(real xr_buf[2][SBLIMIT][SSLIMIT],int *scalefac,
   struct gr_info_s *gr_infos,int sfreq,int ms_stereo,int lsf)
{
      real (*xr)[SBLIMIT*SSLIMIT] = (real (*)[SBLIMIT*SSLIMIT] ) xr_buf;
      struct bandInfoStruct *bi = (struct bandInfoStruct *)&bandInfo[sfreq];
      real *tabl1,*tabl2;

      if(lsf) {
        int p = gr_infos->scalefac_compress & 0x1;
            if(ms_stereo) {
          tabl1 = pow1_2[p]; tabl2 = pow2_2[p];
        }
        else {
          tabl1 = pow1_1[p]; tabl2 = pow2_1[p];
        }
      }
      else {
        if(ms_stereo) {
          tabl1 = tan1_2; tabl2 = tan2_2;
        }
        else {
          tabl1 = tan1_1; tabl2 = tan2_1;
        }
      }

      if (gr_infos->block_type == 2)
      {
         int lwin,do_l = 0;
         if( gr_infos->mixed_block_flag )
           do_l = 1;

         for (lwin=0;lwin<3;lwin++) /* process each window */
         {
             /* get first band with zero values */
           int is_p,sb,idx,sfb = gr_infos->maxband[lwin];  /* sfb is minimal 3 for mixed mode */
           if(sfb > 3)
             do_l = 0;

           for(;sfb<12;sfb++)
           {
             is_p = scalefac[sfb*3+lwin-gr_infos->mixed_block_flag]; /* scale: 0-15 */
             if(is_p != 7) {
               real t1,t2;
               sb = bi->shortDiff[sfb];
               idx = bi->shortIdx[sfb] + lwin;
               t1 = tabl1[is_p]; t2 = tabl2[is_p];
               for (; sb > 0; sb--,idx+=3)
               {
                 real v = xr[0][idx];
                 xr[0][idx] = v * t1;
                 xr[1][idx] = v * t2;
               }
             }
           }

#if 1
/* in the original: copy 10 to 11 , here: copy 11 to 12
maybe still wrong??? (copy 12 to 13?) */
           is_p = scalefac[11*3+lwin-gr_infos->mixed_block_flag]; /* scale: 0-15 */
           sb = bi->shortDiff[12];
           idx = bi->shortIdx[12] + lwin;
#else
           is_p = scalefac[10*3+lwin-gr_infos->mixed_block_flag]; /* scale: 0-15 */
           sb = bi->shortDiff[11];
           idx = bi->shortIdx[11] + lwin;
#endif
           if(is_p != 7)
           {
             real t1,t2;
             t1 = tabl1[is_p]; t2 = tabl2[is_p];
             for ( ; sb > 0; sb--,idx+=3 )
             {
               real v = xr[0][idx];
               xr[0][idx] = v * t1;
               xr[1][idx] = v * t2;
             }
           }
         } /* end for(lwin; .. ; . ) */

         if (do_l)
         {
/* also check l-part, if ALL bands in the three windows are 'empty'
 * and mode = mixed_mode
 */
           int sfb = gr_infos->maxbandl;
           int idx = bi->longIdx[sfb];

           for ( ; sfb<8; sfb++ )
           {
             int sb = bi->longDiff[sfb];
             int is_p = scalefac[sfb]; /* scale: 0-15 */
             if(is_p != 7) {
               real t1,t2;
               t1 = tabl1[is_p]; t2 = tabl2[is_p];
               for ( ; sb > 0; sb--,idx++)
               {
                 real v = xr[0][idx];
                 xr[0][idx] = v * t1;
                 xr[1][idx] = v * t2;
               }
             }
             else
               idx += sb;
           }
         }
      }
      else /* ((gr_infos->block_type != 2)) */
      {
        int sfb = gr_infos->maxbandl;
        int is_p,idx = bi->longIdx[sfb];
        for ( ; sfb<21; sfb++)
        {
          int sb = bi->longDiff[sfb];
          is_p = scalefac[sfb]; /* scale: 0-15 */
          if(is_p != 7) {
            real t1,t2;
            t1 = tabl1[is_p]; t2 = tabl2[is_p];
            for ( ; sb > 0; sb--,idx++)
            {
               real v = xr[0][idx];
               xr[0][idx] = v * t1;
               xr[1][idx] = v * t2;
            }
          }
          else
            idx += sb;
        }

        is_p = scalefac[20]; /* copy l-band 20 to l-band 21 */
        if(is_p != 7)
        {
          int sb;
          real t1 = tabl1[is_p],t2 = tabl2[is_p];

          for ( sb = bi->longDiff[21]; sb > 0; sb--,idx++ )
          {
            real v = xr[0][idx];
            xr[0][idx] = v * t1;
            xr[1][idx] = v * t2;
          }
        }
      } /* ... */
}

static void III_antialias(real xr[SBLIMIT][SSLIMIT],struct gr_info_s *gr_infos)
{
   int sblim;

   if(gr_infos->block_type == 2)
   {
      if(!gr_infos->mixed_block_flag)
        return;
      sblim = 1;
   }
   else {
     sblim = gr_infos->maxb-1;
   }

   /* 31 alias-reduction operations between each pair of sub-bands */
   /* with 8 butterflies between each pair                         */

   {
     int sb;
     real *xr1=(real *) xr[1];

     for(sb=sblim;sb;sb--,xr1+=10)
     {
       int ss;
       real *cs=aa_cs,*ca=aa_ca;
       real *xr2 = xr1;

       for(ss=7;ss>=0;ss--)
       {       /* upper and lower butterfly inputs */
         real bu = *--xr2,bd = *xr1;
         *xr2   = (bu * (*cs)   ) - (bd * (*ca)   );
         *xr1++ = (bd * (*cs++) ) + (bu * (*ca++) );
       }
     }
  }
}

/*
 DCT insipired by Jeff Tsay's DCT from the maplay package
 this is an optimized version with manual unroll.

 References:
 [1] S. Winograd: "On Computing the Discrete Fourier Transform",
     Mathematics of Computation, Volume 32, Number 141, January 1978,
     Pages 175-199
*/

static void dct36(real *inbuf,real *o1,real *o2,real *wintab,real *tsbuf)
{
  {
    real *in = inbuf;

    in[17]+=in[16]; in[16]+=in[15]; in[15]+=in[14];
    in[14]+=in[13]; in[13]+=in[12]; in[12]+=in[11];
    in[11]+=in[10]; in[10]+=in[9];  in[9] +=in[8];
    in[8] +=in[7];  in[7] +=in[6];  in[6] +=in[5];
    in[5] +=in[4];  in[4] +=in[3];  in[3] +=in[2];
    in[2] +=in[1];  in[1] +=in[0];

    in[17]+=in[15]; in[15]+=in[13]; in[13]+=in[11]; in[11]+=in[9];
    in[9] +=in[7];  in[7] +=in[5];  in[5] +=in[3];  in[3] +=in[1];


  {

#define MACRO0(v) { \
    real tmp; \
    out2[9+(v)] = (tmp = sum0 + sum1) * w[27+(v)]; \
    out2[8-(v)] = tmp * w[26-(v)];  } \
    sum0 -= sum1; \
    ts[SBLIMIT*(8-(v))] = out1[8-(v)] + sum0 * w[8-(v)]; \
    ts[SBLIMIT*(9+(v))] = out1[9+(v)] + sum0 * w[9+(v)];
#define MACRO1(v) { \
        real sum0,sum1; \
    sum0 = tmp1a + tmp2a; \
        sum1 = (tmp1b + tmp2b) * tfcos36[(v)]; \
        MACRO0(v); }
#define MACRO2(v) { \
    real sum0,sum1; \
    sum0 = tmp2a - tmp1a; \
    sum1 = (tmp2b - tmp1b) * tfcos36[(v)]; \
        MACRO0(v); }

    const real *c = COS9;
    real *out2 = o2;
        real *w = wintab;
        real *out1 = o1;
        real *ts = tsbuf;

    real ta33,ta66,tb33,tb66;

    ta33 = in[2*3+0] * c[3];
    ta66 = in[2*6+0] * c[6];
    tb33 = in[2*3+1] * c[3];
    tb66 = in[2*6+1] * c[6];

    {
      real tmp1a,tmp2a,tmp1b,tmp2b;
      tmp1a =             in[2*1+0] * c[1] + ta33 + in[2*5+0] * c[5] + in[2*7+0] * c[7];
      tmp1b =             in[2*1+1] * c[1] + tb33 + in[2*5+1] * c[5] + in[2*7+1] * c[7];
      tmp2a = in[2*0+0] + in[2*2+0] * c[2] + in[2*4+0] * c[4] + ta66 + in[2*8+0] * c[8];
      tmp2b = in[2*0+1] + in[2*2+1] * c[2] + in[2*4+1] * c[4] + tb66 + in[2*8+1] * c[8];

      MACRO1(0);
      MACRO2(8);
    }

    {
      real tmp1a,tmp2a,tmp1b,tmp2b;
      tmp1a = ( in[2*1+0] - in[2*5+0] - in[2*7+0] ) * c[3];
      tmp1b = ( in[2*1+1] - in[2*5+1] - in[2*7+1] ) * c[3];
      tmp2a = ( in[2*2+0] - in[2*4+0] - in[2*8+0] ) * c[6] - in[2*6+0] + in[2*0+0];
      tmp2b = ( in[2*2+1] - in[2*4+1] - in[2*8+1] ) * c[6] - in[2*6+1] + in[2*0+1];

      MACRO1(1);
      MACRO2(7);
    }

    {
      real tmp1a,tmp2a,tmp1b,tmp2b;
      tmp1a =             in[2*1+0] * c[5] - ta33 - in[2*5+0] * c[7] + in[2*7+0] * c[1];
      tmp1b =             in[2*1+1] * c[5] - tb33 - in[2*5+1] * c[7] + in[2*7+1] * c[1];
      tmp2a = in[2*0+0] - in[2*2+0] * c[8] - in[2*4+0] * c[2] + ta66 + in[2*8+0] * c[4];
      tmp2b = in[2*0+1] - in[2*2+1] * c[8] - in[2*4+1] * c[2] + tb66 + in[2*8+1] * c[4];

      MACRO1(2);
      MACRO2(6);
    }

    {
      real tmp1a,tmp2a,tmp1b,tmp2b;
      tmp1a =             in[2*1+0] * c[7] - ta33 + in[2*5+0] * c[1] - in[2*7+0] * c[5];
      tmp1b =             in[2*1+1] * c[7] - tb33 + in[2*5+1] * c[1] - in[2*7+1] * c[5];
      tmp2a = in[2*0+0] - in[2*2+0] * c[4] + in[2*4+0] * c[8] + ta66 - in[2*8+0] * c[2];
      tmp2b = in[2*0+1] - in[2*2+1] * c[4] + in[2*4+1] * c[8] + tb66 - in[2*8+1] * c[2];

      MACRO1(3);
      MACRO2(5);
    }

        {
                real sum0,sum1;
        sum0 =  in[2*0+0] - in[2*2+0] + in[2*4+0] - in[2*6+0] + in[2*8+0];
        sum1 = (in[2*0+1] - in[2*2+1] + in[2*4+1] - in[2*6+1] + in[2*8+1] ) * tfcos36[4];
                MACRO0(4);
        }
  }

  }
}

/*
 * new DCT12
 */
static void dct12(real *in,real *rawout1,real *rawout2,real *wi,real *ts)
{
#define DCT12_PART1 \
             in5 = in[5*3];  \
     in5 += (in4 = in[4*3]); \
     in4 += (in3 = in[3*3]); \
     in3 += (in2 = in[2*3]); \
     in2 += (in1 = in[1*3]); \
     in1 += (in0 = in[0*3]); \
                             \
     in5 += in3; in3 += in1; \
                             \
     in2 *= COS6_1; \
     in3 *= COS6_1; \

#define DCT12_PART2 \
     in0 += in4 * COS6_2; \
                          \
     in4 = in0 + in2;     \
     in0 -= in2;          \
                          \
     in1 += in5 * COS6_2; \
                          \
     in5 = (in1 + in3) * tfcos12[0]; \
     in1 = (in1 - in3) * tfcos12[2]; \
                         \
     in3 = in4 + in5;    \
     in4 -= in5;         \
                         \
     in2 = in0 + in1;    \
     in0 -= in1;


   {
     real in0,in1,in2,in3,in4,in5;
     real *out1 = rawout1;
     ts[SBLIMIT*0] = out1[0]; ts[SBLIMIT*1] = out1[1]; ts[SBLIMIT*2] = out1[2];
     ts[SBLIMIT*3] = out1[3]; ts[SBLIMIT*4] = out1[4]; ts[SBLIMIT*5] = out1[5];

     DCT12_PART1

     {
       real tmp0,tmp1 = (in0 - in4);
       {
         real tmp2 = (in1 - in5) * tfcos12[1];
         tmp0 = tmp1 + tmp2;
         tmp1 -= tmp2;
       }
       ts[(17-1)*SBLIMIT] = out1[17-1] + tmp0 * wi[11-1];
       ts[(12+1)*SBLIMIT] = out1[12+1] + tmp0 * wi[6+1];
       ts[(6 +1)*SBLIMIT] = out1[6 +1] + tmp1 * wi[1];
       ts[(11-1)*SBLIMIT] = out1[11-1] + tmp1 * wi[5-1];
     }

     DCT12_PART2

     ts[(17-0)*SBLIMIT] = out1[17-0] + in2 * wi[11-0];
     ts[(12+0)*SBLIMIT] = out1[12+0] + in2 * wi[6+0];
     ts[(12+2)*SBLIMIT] = out1[12+2] + in3 * wi[6+2];
     ts[(17-2)*SBLIMIT] = out1[17-2] + in3 * wi[11-2];

     ts[(6+0)*SBLIMIT]  = out1[6+0] + in0 * wi[0];
     ts[(11-0)*SBLIMIT] = out1[11-0] + in0 * wi[5-0];
     ts[(6+2)*SBLIMIT]  = out1[6+2] + in4 * wi[2];
     ts[(11-2)*SBLIMIT] = out1[11-2] + in4 * wi[5-2];
  }

  in++;

  {
     real in0,in1,in2,in3,in4,in5;
     real *out2 = rawout2;

     DCT12_PART1

     {
       real tmp0,tmp1 = (in0 - in4);
       {
         real tmp2 = (in1 - in5) * tfcos12[1];
         tmp0 = tmp1 + tmp2;
         tmp1 -= tmp2;
       }
       out2[5-1] = tmp0 * wi[11-1];
       out2[0+1] = tmp0 * wi[6+1];
       ts[(12+1)*SBLIMIT] += tmp1 * wi[1];
       ts[(17-1)*SBLIMIT] += tmp1 * wi[5-1];
     }

     DCT12_PART2

     out2[5-0] = in2 * wi[11-0];
     out2[0+0] = in2 * wi[6+0];
     out2[0+2] = in3 * wi[6+2];
     out2[5-2] = in3 * wi[11-2];

     ts[(12+0)*SBLIMIT] += in0 * wi[0];
     ts[(17-0)*SBLIMIT] += in0 * wi[5-0];
     ts[(12+2)*SBLIMIT] += in4 * wi[2];
     ts[(17-2)*SBLIMIT] += in4 * wi[5-2];
  }

  in++;

  {
     real in0,in1,in2,in3,in4,in5;
     real *out2 = rawout2;
     out2[12]=out2[13]=out2[14]=out2[15]=out2[16]=out2[17]=0.0;

     DCT12_PART1

     {
       real tmp0,tmp1 = (in0 - in4);
       {
         real tmp2 = (in1 - in5) * tfcos12[1];
         tmp0 = tmp1 + tmp2;
         tmp1 -= tmp2;
       }
       out2[11-1] = tmp0 * wi[11-1];
       out2[6 +1] = tmp0 * wi[6+1];
       out2[0+1] += tmp1 * wi[1];
       out2[5-1] += tmp1 * wi[5-1];
     }

     DCT12_PART2

     out2[11-0] = in2 * wi[11-0];
     out2[6 +0] = in2 * wi[6+0];
     out2[6 +2] = in3 * wi[6+2];
     out2[11-2] = in3 * wi[11-2];

     out2[0+0] += in0 * wi[0];
     out2[5-0] += in0 * wi[5-0];
     out2[0+2] += in4 * wi[2];
     out2[5-2] += in4 * wi[5-2];
  }
}

/*
 * III_hybrid
 */
static void III_hybrid( PMPSTR mp, real fsIn[SBLIMIT][SSLIMIT],real tsOut[SSLIMIT][SBLIMIT],
   int ch,struct gr_info_s *gr_infos)
{
   real *tspnt = (real *) tsOut;
   real (*block)[2][SBLIMIT*SSLIMIT] = mp->hybrid_block;
   int *blc = mp->hybrid_blc;
   real *rawout1,*rawout2;
   int bt;
   int sb = 0;

   {
     int b = blc[ch];
     rawout1=block[b][ch];
     b=-b+1;
     rawout2=block[b][ch];
     blc[ch] = b;
   }


   if(gr_infos->mixed_block_flag) {
     sb = 2;
     dct36(fsIn[0],rawout1,rawout2,win[0],tspnt);
     dct36(fsIn[1],rawout1+18,rawout2+18,win1[0],tspnt+1);
     rawout1 += 36; rawout2 += 36; tspnt += 2;
   }

   bt = gr_infos->block_type;
   if(bt == 2) {
     for (; sb<(int)gr_infos->maxb; sb+=2,tspnt+=2,rawout1+=36,rawout2+=36) {
       dct12(fsIn[sb],rawout1,rawout2,win[2],tspnt);
       dct12(fsIn[sb+1],rawout1+18,rawout2+18,win1[2],tspnt+1);
     }
   }
   else {
     for (; sb<(int)gr_infos->maxb; sb+=2,tspnt+=2,rawout1+=36,rawout2+=36) {
       dct36(fsIn[sb],rawout1,rawout2,win[bt],tspnt);
       dct36(fsIn[sb+1],rawout1+18,rawout2+18,win1[bt],tspnt+1);
     }
   }

   for(;sb<SBLIMIT;sb++,tspnt++) {
     int i;
     for(i=0;i<SSLIMIT;i++) {
       tspnt[i*SBLIMIT] = *rawout1++;
       *rawout2++ = 0.0;
     }
   }
}

/*
 * main layer3 handler
 */
struct III_sideinfo sideinfo;

int do_layer3_sideinfo(PMPSTR mp)
{
  struct frame *fr = &mp->fr;
  int stereo = fr->stereo;
  int single = fr->single;
  int ms_stereo;
  int sfreq = fr->sampling_frequency;
  int granules;
  int ch,gr,databits;

  if(stereo == 1) { /* stream is mono */
    single = 0;
  }

  if(fr->mode == MPG_MD_JOINT_STEREO) {
    ms_stereo = fr->mode_ext & 0x2;
  }
  else
    ms_stereo = 0;


  if(fr->lsf) {
    granules = 1;
    III_get_side_info_2(mp,&sideinfo,stereo,ms_stereo,sfreq,single);
  }
  else {
    granules = 2;
    III_get_side_info_1(mp,&sideinfo,stereo,ms_stereo,sfreq,single);
  }

  databits=0;
  for (gr=0 ; gr < granules ; ++gr) {
    for (ch=0; ch < stereo ; ++ch) {
      struct gr_info_s *gr_infos = &(sideinfo.ch[ch].gr[gr]);
      databits += gr_infos->part2_3_length;
    }
  }
  return databits-8*sideinfo.main_data_begin;
}



int  do_layer3( PMPSTR mp,unsigned char *pcm_sample,int *pcm_point,
                int (*synth_1to1_mono_ptr)(PMPSTR,real *,unsigned char *,int *),
                int (*synth_1to1_ptr)(PMPSTR,real *,int,unsigned char *, int *) )
{
  int gr, ch, ss,clip=0;
  int scalefacs[2][39]; /* max 39 for short[13][3] mode, mixed: 38, long: 22 */
  /*  struct III_sideinfo sideinfo; */
  struct frame *fr=&(mp->fr);
  int stereo = fr->stereo;
  int single = fr->single;
  int ms_stereo,i_stereo;
  int sfreq = fr->sampling_frequency;
  int stereo1,granules;

  if(set_pointer(mp, (int)sideinfo.main_data_begin) == MP3_ERR)
    return 0;

  if(stereo == 1) { /* stream is mono */
    stereo1 = 1;
    single = 0;
  }
  else if(single >= 0) /* stream is stereo, but force to mono */
    stereo1 = 1;
  else
    stereo1 = 2;

  if(fr->mode == MPG_MD_JOINT_STEREO) {
    ms_stereo = fr->mode_ext & 0x2;
    i_stereo  = fr->mode_ext & 0x1;
  }
  else
    ms_stereo = i_stereo = 0;


  if(fr->lsf) {
    granules = 1;
  }
  else {
    granules = 2;
  }


  for (gr=0;gr<granules;gr++)
  {
    static real hybridIn[2][SBLIMIT][SSLIMIT];
    static real hybridOut[2][SSLIMIT][SBLIMIT];

    {
      struct gr_info_s *gr_infos = &(sideinfo.ch[0].gr[gr]);
      long part2bits;

      if(fr->lsf)
        part2bits = III_get_scale_factors_2(mp,scalefacs[0],gr_infos,0);
      else {
        part2bits = III_get_scale_factors_1(mp,scalefacs[0],gr_infos);
      }

#ifndef NOANALYSIS
      if (mpg123_pinfo!=NULL) {
        int i;
        mpg123_pinfo->sfbits[gr][0] = part2bits;
        for (i=0; i<39; i++)
          mpg123_pinfo->sfb_s[gr][0][i]=scalefacs[0][i];
      }
#endif

      if(III_dequantize_sample(mp, hybridIn[0], scalefacs[0],gr_infos,sfreq,part2bits))
        return clip;
    }
    if(stereo == 2) {
      struct gr_info_s *gr_infos = &(sideinfo.ch[1].gr[gr]);
      long part2bits;
      if(fr->lsf)
        part2bits = III_get_scale_factors_2(mp,scalefacs[1],gr_infos,i_stereo);
      else {
        part2bits = III_get_scale_factors_1(mp,scalefacs[1],gr_infos);
      }
#ifndef NOANALYSIS
      if (mpg123_pinfo!=NULL) {
        int i;
        mpg123_pinfo->sfbits[gr][1] = part2bits;
        for (i=0; i<39; i++)
          mpg123_pinfo->sfb_s[gr][1][i]=scalefacs[1][i];
      }
#endif

      if(III_dequantize_sample(mp, hybridIn[1],scalefacs[1],gr_infos,sfreq,part2bits))
          return clip;

      if(ms_stereo) {
        int i;
        for(i=0;i<SBLIMIT*SSLIMIT;i++) {
          real tmp0,tmp1;
          tmp0 = ((real *) hybridIn[0])[i];
          tmp1 = ((real *) hybridIn[1])[i];
          ((real *) hybridIn[1])[i] = tmp0 - tmp1;
          ((real *) hybridIn[0])[i] = tmp0 + tmp1;
        }
      }

      if(i_stereo)
        III_i_stereo(hybridIn,scalefacs[1],gr_infos,sfreq,ms_stereo,fr->lsf);

      if(ms_stereo || i_stereo || (single == 3) ) {
        if(gr_infos->maxb > sideinfo.ch[0].gr[gr].maxb)
          sideinfo.ch[0].gr[gr].maxb = gr_infos->maxb;
        else
          gr_infos->maxb = sideinfo.ch[0].gr[gr].maxb;
      }

      switch(single) {
        case 3:
          {
            int i;
            real *in0 = (real *) hybridIn[0],*in1 = (real *) hybridIn[1];
            for(i=0;i<(int)(SSLIMIT*gr_infos->maxb);i++,in0++)
              *in0 = (*in0 + *in1++); /* *0.5 done by pow-scale */
          }
          break;
        case 1:
          {
            int i;
            real *in0 = (real *) hybridIn[0],*in1 = (real *) hybridIn[1];
            for(i=0;i<(int)(SSLIMIT*gr_infos->maxb);i++)
              *in0++ = *in1++;
          }
          break;
      }
    }

#ifndef NOANALYSIS
    if (mpg123_pinfo!=NULL) {
    int i,sb;
    float ifqstep;

    mpg123_pinfo->bitrate =
      tabsel_123[fr->lsf][fr->lay-1][fr->bitrate_index];
    mpg123_pinfo->sampfreq = freqs[sfreq];
    mpg123_pinfo->emph = fr->emphasis;
    mpg123_pinfo->crc = fr->error_protection;
    mpg123_pinfo->padding = fr->padding;
    mpg123_pinfo->stereo = fr->stereo;
    mpg123_pinfo->js =   (fr->mode == MPG_MD_JOINT_STEREO);
    mpg123_pinfo->ms_stereo = ms_stereo;
    mpg123_pinfo->i_stereo = i_stereo;
    mpg123_pinfo->maindata = sideinfo.main_data_begin;

    for(ch=0;ch<stereo1;ch++) {
      struct gr_info_s *gr_infos = &(sideinfo.ch[ch].gr[gr]);
      mpg123_pinfo->big_values[gr][ch]=gr_infos->big_values;
      mpg123_pinfo->scalefac_scale[gr][ch]=gr_infos->scalefac_scale;
      mpg123_pinfo->mixed[gr][ch] = gr_infos->mixed_block_flag;
      mpg123_pinfo->mpg123blocktype[gr][ch]=gr_infos->block_type;
      mpg123_pinfo->mainbits[gr][ch] = gr_infos->part2_3_length;
      mpg123_pinfo->preflag[gr][ch] = gr_infos->preflag;
      if (gr==1) mpg123_pinfo->scfsi[ch] = gr_infos->scfsi;
    }


    for (ch=0;ch<stereo1;ch++) {
      struct gr_info_s *gr_infos = &(sideinfo.ch[ch].gr[gr]);
      ifqstep = ( mpg123_pinfo->scalefac_scale[gr][ch] == 0 ) ? .5 : 1.0;
      if (2==gr_infos->block_type) {
        for (i=0; i<3; i++) {
          for (sb=0; sb<12; sb++) {
            int j = 3*sb+i;
            /*
           is_p = scalefac[sfb*3+lwin-gr_infos->mixed_block_flag];
            */
            /* scalefac was copied into mpg123_pinfo->sfb_s[] above */
            mpg123_pinfo->sfb_s[gr][ch][j] = -ifqstep*mpg123_pinfo->sfb_s[gr][ch][j-gr_infos->mixed_block_flag];
            mpg123_pinfo->sfb_s[gr][ch][j] -= 2*(mpg123_pinfo->sub_gain[gr][ch][i]);
          }
          mpg123_pinfo->sfb_s[gr][ch][3*sb+i] = - 2*(mpg123_pinfo->sub_gain[gr][ch][i]);
        }
      }else{
        for (sb=0; sb<21; sb++) {
          /* scalefac was copied into mpg123_pinfo->sfb[] above */
          mpg123_pinfo->sfb[gr][ch][sb] = mpg123_pinfo->sfb_s[gr][ch][sb];
          if (gr_infos->preflag) mpg123_pinfo->sfb[gr][ch][sb] += pretab1[sb];
          mpg123_pinfo->sfb[gr][ch][sb] *= -ifqstep;
        }
        mpg123_pinfo->sfb[gr][ch][21]=0;
      }
    }



    for(ch=0;ch<stereo1;ch++) {
      int j=0;
      for (sb=0;sb<SBLIMIT;sb++)
        for(ss=0;ss<SSLIMIT;ss++,j++)
          mpg123_pinfo->mpg123xr[gr][ch][j]=hybridIn[ch][sb][ss];
    }
  }
#endif


    for(ch=0;ch<stereo1;ch++) {
      struct gr_info_s *gr_infos = &(sideinfo.ch[ch].gr[gr]);
      III_antialias(hybridIn[ch],gr_infos);
      III_hybrid(mp, hybridIn[ch], hybridOut[ch], ch,gr_infos);
    }

    for(ss=0;ss<SSLIMIT;ss++) {
      if(single >= 0) {
        clip += (*synth_1to1_mono_ptr)(mp, hybridOut[0][ss],pcm_sample,pcm_point);
      }
      else {
        int p1 = *pcm_point;
        clip += (*synth_1to1_ptr)(mp, hybridOut[0][ss],0,pcm_sample,&p1);
        clip += (*synth_1to1_ptr)(mp, hybridOut[1][ss],1,pcm_sample,pcm_point);
      }
    }
  }

  return clip;
}

---