decoders/libmpg123/layer3.c

/*
	leyer3.c: the layer 3 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

	Optimize-TODO: put short bands into the band-field without the stride of 3 reals
	Length-optimze: unify long and short band code where it is possible

	The int-vs-pointer situation has to be cleaned up.
*/

#include "mpg123lib_intern.h"
#include "huffman.h"
#include "getbits.h"
#include "debug.h"

/* static one-time calculated tables... or so */
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];
real COS9[9]; /* dct36_3dnow wants to use that */
static real COS6_1,COS6_2;
real tfcos36[9]; /* dct36_3dnow wants to use that */
static real tfcos12[3];
#define NEW_DCT9
#ifdef NEW_DCT9
static real cos9[3],cos18[3];
#endif

struct gr_info_s {
      int scfsi;
      unsigned part2_3_length;
      unsigned big_values;
      unsigned scalefac_compress;
      unsigned block_type;
      unsigned mixed_block_flag;
      unsigned table_select[3];
      unsigned subblock_gain[3];
      unsigned maxband[3];
      unsigned maxbandl;
      unsigned maxb;
      unsigned region1start;
      unsigned region2start;
      unsigned preflag;
      unsigned scalefac_scale;
      unsigned count1table_select;
      real *full_gain[3];
      real *pow2gain;
};

struct III_sideinfo
{
  unsigned main_data_begin;
  unsigned private_bits;
  struct {
    struct gr_info_s gr[2];
  } ch[2];
};


struct bandInfoStruct {
  int longIdx[23];
  int longDiff[22];
  int shortIdx[14];
  int shortDiff[13];
};


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 } } ,

/* Twiddling 3 values here (not just 330->332!) fixed bug 1895025. */
 { {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];

#ifdef OPT_MMXORSSE
real init_layer3_gainpow2_mmx(mpg123_handle *fr, int i)
{
	if(!fr->p.down_sample) return 16384.0 * pow((double)2.0,-0.25 * (double) (i+210) );
	else return DOUBLE_TO_REAL(pow((double)2.0,-0.25 * (double) (i+210)));
}
#endif

real init_layer3_gainpow2(mpg123_handle *fr, int i)
{
	return DOUBLE_TO_REAL(pow((double)2.0,-0.25 * (double) (i+210)));
}

/* 
 * init tables for layer-3 ... specific with the downsampling...
 */
void init_layer3(void)
{
  int i,j,k,l;

  for(i=0;i<8207;i++)
    ispow[i] = DOUBLE_TO_REAL(pow((double)i,(double)4.0/3.0));

  for (i=0;i<8;i++) {
    const 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] = DOUBLE_TO_REAL(1.0/sq);
    aa_ca[i] = DOUBLE_TO_REAL(Ci[i]/sq);
  }

  for(i=0;i<18;i++) {
    win[0][i]    = win[1][i]    = DOUBLE_TO_REAL(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] = DOUBLE_TO_REAL(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] = DOUBLE_TO_REAL(0.5 / cos ( M_PI * (double) (2*(i+18)+19) / 72.0 ));
    win[3][i+12] = DOUBLE_TO_REAL(0.5 / cos ( M_PI * (double) (2*(i+12)+19) / 72.0 ));
    win[1][i+24] = DOUBLE_TO_REAL(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] = DOUBLE_TO_REAL(0.0);
    win[3][i+6 ] = DOUBLE_TO_REAL(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] = DOUBLE_TO_REAL(cos( M_PI / 18.0 * (double) i));

  for(i=0;i<9;i++)
    tfcos36[i] = DOUBLE_TO_REAL(0.5 / cos ( M_PI * (double) (i*2+1) / 36.0 ));
  for(i=0;i<3;i++)
    tfcos12[i] = DOUBLE_TO_REAL(0.5 / cos ( M_PI * (double) (i*2+1) / 12.0 ));

  COS6_1 = DOUBLE_TO_REAL(cos( M_PI / 6.0 * (double) 1));
  COS6_2 = DOUBLE_TO_REAL(cos( M_PI / 6.0 * (double) 2));

#ifdef NEW_DCT9
  cos9[0]  = DOUBLE_TO_REAL(cos(1.0*M_PI/9.0));
  cos9[1]  = DOUBLE_TO_REAL(cos(5.0*M_PI/9.0));
  cos9[2]  = DOUBLE_TO_REAL(cos(7.0*M_PI/9.0));
  cos18[0] = DOUBLE_TO_REAL(cos(1.0*M_PI/18.0));
  cos18[1] = DOUBLE_TO_REAL(cos(11.0*M_PI/18.0));
  cos18[2] = DOUBLE_TO_REAL(cos(13.0*M_PI/18.0));
#endif

  for(i=0;i<12;i++) {
    win[2][i]  = DOUBLE_TO_REAL(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] = DOUBLE_TO_REAL(cos( M_PI / 24.0 * (double) ((2*i+7)*(2*j+1)) ));
  }

  for(j=0;j<4;j++) {
    const 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] = DOUBLE_TO_REAL(t / (1.0+t));
    tan2_1[i] = DOUBLE_TO_REAL(1.0 / (1.0 + t));
    tan1_2[i] = DOUBLE_TO_REAL(M_SQRT2 * t / (1.0+t));
    tan2_2[i] = DOUBLE_TO_REAL(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] = DOUBLE_TO_REAL(p1);
      pow2_1[j][i] = DOUBLE_TO_REAL(p2);
      pow1_2[j][i] = DOUBLE_TO_REAL(M_SQRT2 * p1);
      pow2_2[j][i] = DOUBLE_TO_REAL(M_SQRT2 * p2);
    }
  }

  for(j=0;j<9;j++) {
   const struct bandInfoStruct *bi = &bandInfo[j];
   int *mp;
   int cb,lwin;
   const int *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(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);
      }
    }
  }
}

void init_layer3_stuff(mpg123_handle *fr)
{
	int i,j;

	for(i=-256;i<118+4;i++)	fr->gainpow2[i+256] = opt_init_layer3_gainpow2(fr)(fr,i);

	for(j=0;j<9;j++)
	{
		for(i=0;i<23;i++)
		{
			fr->longLimit[j][i] = (bandInfo[j].longIdx[i] - 1 + 8) / 18 + 1;
			if(fr->longLimit[j][i] > (fr->down_sample_sblimit) )
			fr->longLimit[j][i] = fr->down_sample_sblimit;
		}
		for(i=0;i<14;i++)
		{
			fr->shortLimit[j][i] = (bandInfo[j].shortIdx[i] - 1) / 18 + 1;
			if(fr->shortLimit[j][i] > (fr->down_sample_sblimit) )
			fr->shortLimit[j][i] = fr->down_sample_sblimit;
		}
	}
}


/*
 * read additional side information (for MPEG 1 and MPEG 2)
 */
static int III_get_side_info(mpg123_handle *fr, struct III_sideinfo *si,int stereo,
 int ms_stereo,long sfreq,int single)
{
   int ch, gr;
   int powdiff = (single == SINGLE_MIX) ? 4 : 0;

   const int tabs[2][5] = { { 2,9,5,3,4 } , { 1,8,1,2,9 } };
   const int *tab = tabs[fr->lsf];

   si->main_data_begin = getbits(fr, tab[1]);

   if(si->main_data_begin > fr->bitreservoir)
   {
     if(NOQUIET) error2("missing %d bytes in bit reservoir for frame %li", (int)(si->main_data_begin - fr->bitreservoir), (long)fr->num);

     /*  overwrite main_data_begin for the really available bit reservoir */
     backbits(fr, tab[1]);
     if(fr->lsf == 0)
     {
       fr->wordpointer[0] = (unsigned char) (fr->bitreservoir >> 1);
       fr->wordpointer[1] = (unsigned char) ((fr->bitreservoir & 1) << 7);
     }
     else fr->wordpointer[0] = (unsigned char) fr->bitreservoir;

     /* zero "side-info" data for a silence-frame
        without touching audio data used as bit reservoir for following frame */
     memset(fr->wordpointer+2, 0, fr->ssize-2);

     /* reread the new bit reservoir offset */
     si->main_data_begin = getbits(fr, tab[1]);
   }

   /* Keep track of the available data bytes for the bit reservoir.
      Think: Substract the 2 crc bytes in parser already? */
   fr->bitreservoir = fr->bitreservoir + fr->framesize - fr->ssize - (fr->error_protection ? 2 : 0);
    /* Limit the reservoir to the max for MPEG 1.0 or 2.x . */
   if(fr->bitreservoir > (fr->lsf == 0 ? 511 : 255))
   fr->bitreservoir = (fr->lsf == 0 ? 511 : 255);

   if (stereo == 1)
     si->private_bits = getbits_fast(fr, tab[2]);
   else 
     si->private_bits = getbits_fast(fr, tab[3]);

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

   for (gr=0; gr<tab[0]; 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(fr, 12);
       gr_info->big_values = getbits(fr, 9);
       if(gr_info->big_values > 288) {
          error("big_values too large!");
          gr_info->big_values = 288;
       }
       gr_info->pow2gain = fr->gainpow2+256 - getbits_fast(fr, 8) + powdiff;
       if(ms_stereo)
         gr_info->pow2gain += 2;
       gr_info->scalefac_compress = getbits(fr, tab[4]);

       if(get1bit(fr)) { /* window switch flag  */
         int i;
         gr_info->block_type       = getbits_fast(fr, 2);
         gr_info->mixed_block_flag = get1bit(fr);
         gr_info->table_select[0]  = getbits_fast(fr, 5);
         gr_info->table_select[1]  = getbits_fast(fr, 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(fr, 3)<<3);

         if(gr_info->block_type == 0) {
           error("Blocktype == 0 and window-switching == 1 not allowed.");
           /* exit(1); */
           return 1;
         }
      
         /* region_count/start parameters are implicit in this case. */       
         if( (!fr->lsf || (gr_info->block_type == 2)) && !fr->mpeg25)
         {
           gr_info->region1start = 36>>1;
           gr_info->region2start = 576>>1;
         }
         else {
           if(fr->mpeg25) { 
             int r0c,r1c;
             if((gr_info->block_type == 2) && (!gr_info->mixed_block_flag) ) 
               r0c = 5;
             else 
               r0c = 7;
             r1c = 20 - r0c;
             gr_info->region1start = bandInfo[sfreq].longIdx[r0c+1] >> 1 ;
             gr_info->region2start = bandInfo[sfreq].longIdx[r0c+1+r1c+1] >> 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(fr, 5);
         r0c = getbits_fast(fr, 4);
         r1c = getbits_fast(fr, 3);
         gr_info->region1start = bandInfo[sfreq].longIdx[r0c+1] >> 1 ;
         gr_info->region2start = bandInfo[sfreq].longIdx[r0c+1+r1c+1] >> 1;
         if(r0c + r1c + 2 > 22)
           gr_info->region2start = 576>>1;
         else
           gr_info->region2start = bandInfo[sfreq].longIdx[r0c+1+r1c+1] >> 1;
         gr_info->block_type = 0;
         gr_info->mixed_block_flag = 0;
       }
       if(!fr->lsf)
         gr_info->preflag = get1bit(fr);
       gr_info->scalefac_scale = get1bit(fr);
       gr_info->count1table_select = get1bit(fr);
     }
   }
   return 0;
}

/*
 * read scalefactors
 */
static int III_get_scale_factors_1(mpg123_handle *fr, int *scf,struct gr_info_s *gr_info,int ch,int gr)
{
   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_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(fr, num0);
         i = 9;
         numbits -= num0; /* num0 * 17 + num1 * 18 */
      }

      for (;i;i--)
        *scf++ = getbits_fast(fr, num0);
      for (i = 18; i; i--)
        *scf++ = getbits_fast(fr, 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(fr, num0);
         for(i=10;i;i--)
           *scf++ = getbits_fast(fr, num1);
         numbits = (num0 + num1) * 10 + num0;
         *scf++ = 0;
      }
      else {
        numbits = 0;
        if(!(scfsi & 0x8)) {
          for (i=0;i<6;i++)
            *scf++ = getbits_fast(fr, num0);
          numbits += num0 * 6;
        }
        else {
          scf += 6; 
        }

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

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

        if(!(scfsi & 0x1)) {
          for (i=0;i<5;i++)
            *scf++ = getbits_fast(fr, num1);
          numbits += num1 * 5;
        }
        else {
           scf += 5;
        }
        *scf++ = 0;  /* no l[21] in original sources */
      }
    }
    return numbits;
}

static int III_get_scale_factors_2(mpg123_handle *fr, int *scf,struct gr_info_s *gr_info,int i_stereo)
{
  const unsigned char *pnt;
  int i,j,n=0,numbits=0;
  unsigned int slen;

  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_info->scalefac_compress>>1];
  else
    slen = n_slen2[gr_info->scalefac_compress];

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

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

  pnt = 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(fr, 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};
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};

/*
 * Dequantize samples (includes huffman decoding)
 */
/* 24 is enough because tab13 has max. a 19 bit huffvector */
#define BITSHIFT ((sizeof(long)-1)*8)
#define REFRESH_MASK \
  while(num < BITSHIFT) { \
    mask |= ((unsigned long)getbyte(fr))<<(BITSHIFT-num); \
    num += 8; \
    part2remain -= 8; }

static int III_dequantize_sample(mpg123_handle *fr, real xr[SBLIMIT][SSLIMIT],int *scf,
   struct gr_info_s *gr_info,int sfreq,int part2bits)
{
  int shift = 1 + gr_info->scalefac_scale;
  real *xrpnt = (real *) xr;
  int l[3],l3;
  int part2remain = gr_info->part2_3_length - part2bits;
  int *me;

  /* mhipp tree has this split up a bit... */
  int num=getbitoffset(fr);
  long mask;
  /* We must split this, because for num==0 the shift is undefined if you do it in one step. */
  mask  = ((unsigned long) getbits(fr, num))<<BITSHIFT;
  mask <<= 8-num;
  part2remain -= num;

  {
    int bv       = gr_info->big_values;
    int region1  = gr_info->region1start;
    int region2  = gr_info->region2start;
if(region1 > region2)
{
	/* That's not optimal: it fixes a segfault with fuzzed data, but also apparently triggers where it shouldn't, see bug 1641196.
	   The benefit of not crashing / having this security risk is bigger than these few frames of a lame-3.70 file that aren't audible anyway
	   But still, I want to know if indeed this check or the old lame is at fault. */
	error("You got some really nasty file there... region1>region2!");
	return 1;
}
    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;
      }
    }
  }
 
  if(gr_info->block_type == 2) {
    /*
     * decoding with short or mixed mode BandIndex table 
     */
    int i,max[4];
    int step=0,lwin=3,cb=0;
    register real v = 0.0;
    register int *m,mc;

    if(gr_info->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 = ht+gr_info->table_select[i];
      for(;lp;lp--,mc--) {
        register int x,y;
        if( (!mc) ) {
          mc    = *m++;
          xrpnt = ((real *) xr) + (*m++);
          lwin  = *m++;
          cb    = *m++;
          if(lwin == 3) {
            v = gr_info->pow2gain[(*scf++) << shift];
            step = 1;
          }
          else {
            v = gr_info->full_gain[lwin][(*scf++) << shift];
            step = 3;
          }
        }
        {
          register short *val = h->table;
          REFRESH_MASK;
          while((y=*val++)<0) {
            if (mask < 0)
              val -= y;
            num--;
            mask <<= 1;
          }
          x = y >> 4;
          y &= 0xf;
        }
        if(x == 15 && h->linbits) {
          max[lwin] = cb;
          REFRESH_MASK;
          x += ((unsigned long) mask) >> (BITSHIFT+8-h->linbits);
          num -= h->linbits+1;
          mask <<= h->linbits;
          if(mask < 0)
            *xrpnt = REAL_MUL(-ispow[x], v);
          else
            *xrpnt = REAL_MUL(ispow[x], v);
          mask <<= 1;
        }
        else if(x) {
          max[lwin] = cb;
          if(mask < 0)
            *xrpnt = REAL_MUL(-ispow[x], v);
          else
            *xrpnt = REAL_MUL(ispow[x], v);
          num--;
          mask <<= 1;
        }
        else
          *xrpnt = DOUBLE_TO_REAL(0.0);
        xrpnt += step;
        if(y == 15 && h->linbits) {
          max[lwin] = cb;
          REFRESH_MASK;
          y += ((unsigned long) mask) >> (BITSHIFT+8-h->linbits);
          num -= h->linbits+1;
          mask <<= h->linbits;
          if(mask < 0)
            *xrpnt = REAL_MUL(-ispow[y], v);
          else
            *xrpnt = REAL_MUL(ispow[y], v);
          mask <<= 1;
        }
        else if(y) {
          max[lwin] = cb;
          if(mask < 0)
            *xrpnt = REAL_MUL(-ispow[y], v);
          else
            *xrpnt = REAL_MUL(ispow[y], v);
          num--;
          mask <<= 1;
        }
        else
          *xrpnt = DOUBLE_TO_REAL(0.0);
        xrpnt += step;
      }
    }

    for(;l3 && (part2remain+num > 0);l3--) {
      /* not mixing code and declarations to keep C89 happy */
      struct newhuff* h;
      register short* val;
			register short a;
      /* This is only a humble hack to prevent a special segfault. */
      /* More insight into the real workings is still needed. */
      /* especially why there are (valid?) files that make xrpnt exceed the array with 4 bytes without segfaulting, more seems to be really bad, though. */
      #ifdef DEBUG
      if(!(xrpnt < &xr[SBLIMIT][0]))
      {
        if(VERBOSE) debug2("attempted soft xrpnt overflow (%p !< %p) ?", (void*) xrpnt, (void*) &xr[SBLIMIT][0]);
      }
      #endif
      if(!(xrpnt < &xr[SBLIMIT][0]+5))
      {
        error2("attempted xrpnt overflow (%p !< %p)", (void*) xrpnt, (void*) &xr[SBLIMIT][0]);
        return 2;
      }
      h = htc+gr_info->count1table_select;
      val = h->table;

      REFRESH_MASK;
      while((a=*val++)<0) {
        if (mask < 0)
          val -= a;
        num--;
        mask <<= 1;
      }
      if(part2remain+num <= 0) {
	num -= part2remain+num;
	break;
      }

      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_info->pow2gain[(*scf++) << shift];
              step = 1;
            }
            else {
              v = gr_info->full_gain[lwin][(*scf++) << shift];
              step = 3;
            }
          }
          mc--;
        }
        if( (a & (0x8>>i)) ) {
          max[lwin] = cb;
          if(part2remain+num <= 0) {
            break;
          }
          if(mask < 0) 
            *xrpnt = -v;
          else
            *xrpnt = v;
          num--;
          mask <<= 1;
        }
        else
          *xrpnt = DOUBLE_TO_REAL(0.0);
        xrpnt += step;
      }
    }

    if(lwin < 3) { /* short band? */
      while(1) {
        for(;mc > 0;mc--) {
          *xrpnt = DOUBLE_TO_REAL(0.0); xrpnt += 3; /* short band -> step=3 */
          *xrpnt = DOUBLE_TO_REAL(0.0); xrpnt += 3;
        }
        if(m >= me)
          break;
        mc    = *m++;
        xrpnt = ((real *) xr) + *m++;
        if(*m++ == 0)
          break; /* optimize: field will be set to zero at the end of the function */
        m++; /* cb */
      }
    }

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

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

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

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

      for(;lp;lp--,mc--) {
        int x,y;
        if(!mc) {
          mc = *m++;
          cb = *m++;
          if(cb == 21)
            v = 0.0;
          else
            v = gr_info->pow2gain[((*scf++) + (*pretab++)) << shift];

        }
        {
          register short *val = h->table;
          REFRESH_MASK;
          while((y=*val++)<0) {
            if (mask < 0)
              val -= y;
            num--;
            mask <<= 1;
          }
          x = y >> 4;
          y &= 0xf;
        }

        if (x == 15 && h->linbits) {
          max = cb;
	  REFRESH_MASK;
          x += ((unsigned long) mask) >> (BITSHIFT+8-h->linbits);
          num -= h->linbits+1;
          mask <<= h->linbits;
          if(mask < 0)
            *xrpnt++ = REAL_MUL(-ispow[x], v);
          else
            *xrpnt++ = REAL_MUL(ispow[x], v);
          mask <<= 1;
        }
        else if(x) {
          max = cb;
          if(mask < 0)
            *xrpnt++ = REAL_MUL(-ispow[x], v);
          else
            *xrpnt++ = REAL_MUL(ispow[x], v);
          num--;
          mask <<= 1;
        }
        else
          *xrpnt++ = DOUBLE_TO_REAL(0.0);

        if (y == 15 && h->linbits) {
          max = cb;
	  REFRESH_MASK;
          y += ((unsigned long) mask) >> (BITSHIFT+8-h->linbits);
          num -= h->linbits+1;
          mask <<= h->linbits;
          if(mask < 0)
            *xrpnt++ = REAL_MUL(-ispow[y], v);
          else
            *xrpnt++ = REAL_MUL(ispow[y], v);
          mask <<= 1;
        }
        else if(y) {
          max = cb;
          if(mask < 0)
            *xrpnt++ = REAL_MUL(-ispow[y], v);
          else
            *xrpnt++ = REAL_MUL(ispow[y], v);
          num--;
          mask <<= 1;
        }
        else
          *xrpnt++ = DOUBLE_TO_REAL(0.0);
      }
    }

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

      REFRESH_MASK;
      while((a=*val++)<0) {
        if (mask < 0)
          val -= a;
        num--;
        mask <<= 1;
      }
      if(part2remain+num <= 0) {
	num -= part2remain+num;
        break;
      }

      for(i=0;i<4;i++) {
        if(!(i & 1)) {
          if(!mc) {
            mc = *m++;
            cb = *m++;
            if(cb == 21)
              v = 0.0;
            else
              v = gr_info->pow2gain[((*scf++) + (*pretab++)) << shift];
          }
          mc--;
        }
        if ( (a & (0x8>>i)) ) {
          max = cb;
          if(part2remain+num <= 0) {
            break;
          }
          if(mask < 0)
            *xrpnt++ = -v;
          else
            *xrpnt++ = v;
          num--;
          mask <<= 1;
        }
        else
          *xrpnt++ = DOUBLE_TO_REAL(0.0);
      }
    }

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

  part2remain += num;
  backbits(fr, num);
  num = 0;

  while(xrpnt < &xr[SBLIMIT][0]) 
    *xrpnt++ = DOUBLE_TO_REAL(0.0);

  while( part2remain > 16 ) {
    skipbits(fr, 16); /* Dismiss stuffing Bits */
    part2remain -= 16;
  }
  if(part2remain > 0)
    skipbits(fr, part2remain);
  else if(part2remain < 0) {
    debug1("Can't rewind stream by %d bits!",-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_info,int sfreq,int ms_stereo,int lsf)
{
      real (*xr)[SBLIMIT*SSLIMIT] = (real (*)[SBLIMIT*SSLIMIT] ) xr_buf;
      const struct bandInfoStruct *bi = &bandInfo[sfreq];

      const real *tab1,*tab2;

#if 1
      int tab;
/* TODO: optimize as static */
      const real *tabs[3][2][2] = { 
         { { tan1_1,tan2_1 }     , { tan1_2,tan2_2 } },
         { { pow1_1[0],pow2_1[0] } , { pow1_2[0],pow2_2[0] } } ,
         { { pow1_1[1],pow2_1[1] } , { pow1_2[1],pow2_2[1] } } 
      };

      tab = lsf + (gr_info->scalefac_compress & lsf);
      tab1 = tabs[tab][ms_stereo][0];
      tab2 = tabs[tab][ms_stereo][1];
#else
      if(lsf) {
        int p = gr_info->scalefac_compress & 0x1;
	if(ms_stereo) {
          tab1 = pow1_2[p]; tab2 = pow2_2[p];
        }
        else {
          tab1 = pow1_1[p]; tab2 = pow2_1[p];
        }
      }
      else {
        if(ms_stereo) {
          tab1 = tan1_2; tab2 = tan2_2;
        }
        else {
          tab1 = tan1_1; tab2 = tan2_1;
        }
      }
#endif

      if (gr_info->block_type == 2) {
         int lwin,do_l = 0;
         if( gr_info->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_info->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_info->mixed_block_flag]; /* scale: 0-15 */ 
             if(is_p != 7) {
               real t1,t2;
               sb  = bi->shortDiff[sfb];
               idx = bi->shortIdx[sfb] + lwin;
               t1  = tab1[is_p]; t2 = tab2[is_p];
               for (; sb > 0; sb--,idx+=3) {
                 real v = xr[0][idx];
                 xr[0][idx] = REAL_MUL(v, t1);
                 xr[1][idx] = REAL_MUL(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_info->mixed_block_flag]; /* scale: 0-15 */
           sb   = bi->shortDiff[12];
           idx  = bi->shortIdx[12] + lwin;
#else
           is_p = scalefac[10*3+lwin-gr_info->mixed_block_flag]; /* scale: 0-15 */
           sb   = bi->shortDiff[11];
           idx  = bi->shortIdx[11] + lwin;
#endif
           if(is_p != 7) {
             real t1,t2;
             t1 = tab1[is_p]; t2 = tab2[is_p];
             for ( ; sb > 0; sb--,idx+=3 ) {  
               real v = xr[0][idx];
               xr[0][idx] = REAL_MUL(v, t1);
               xr[1][idx] = REAL_MUL(v, t2);
             }
           }
         } /* end for(lwin; .. ; . ) */

/* also check l-part, if ALL bands in the three windows are 'empty'
 * and mode = mixed_mode 
 */
         if (do_l) {
           int sfb = gr_info->maxbandl;
           int idx;
           if(sfb > 21) return; /* similarity fix related to CVE-2006-1655 */
           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 = tab1[is_p]; t2 = tab2[is_p];
               for ( ; sb > 0; sb--,idx++) {
                 real v = xr[0][idx];
                 xr[0][idx] = REAL_MUL(v, t1);
                 xr[1][idx] = REAL_MUL(v, t2);
               }
             }
             else 
               idx += sb;
           }
         }     
      } 
      else { /* ((gr_info->block_type != 2)) */
        int sfb = gr_info->maxbandl;
        int is_p,idx;
        if(sfb > 21) return; /* tightened fix for CVE-2006-1655 */
        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 = tab1[is_p]; t2 = tab2[is_p];
            for ( ; sb > 0; sb--,idx++) {
               real v = xr[0][idx];
               xr[0][idx] = REAL_MUL(v, t1);
               xr[1][idx] = REAL_MUL(v, t2);
            }
          }
          else
            idx += sb;
        }

        is_p = scalefac[20];
        if(is_p != 7) {  /* copy l-band 20 to l-band 21 */
          int sb;
          real t1 = tab1[is_p],t2 = tab2[is_p]; 

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

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

   if(gr_info->block_type == 2) {
      if(!gr_info->mixed_block_flag) 
        return;
      sblim = 1; 
   }
   else {
     sblim = gr_info->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 */
         register real bu = *--xr2,bd = *xr1;
        *xr2   = REAL_MUL(bu, *cs) - REAL_MUL(bd, *ca);
        *xr1++ = REAL_MUL(bd, *cs++) + REAL_MUL(bu, *ca++);
       }
     }
  }
}

/* 
// This is an optimized DCT from Jeff Tsay's maplay 1.2+ package.
// Saved one multiplication by doing the 'twiddle factor' stuff
// together with the window mul. (MH)
//
// This uses Byeong Gi Lee's Fast Cosine Transform algorithm, but the
// 9 point IDCT needs to be reduced further. Unfortunately, I don't
// know how to do that, because 9 is not an even number. - Jeff.
//
//////////////////////////////////////////////////////////////////
//
// 9 Point Inverse Discrete Cosine Transform
//
// This piece of code is Copyright 1997 Mikko Tommila and is freely usable
// by anybody. The algorithm itself is of course in the public domain.
//
// Again derived heuristically from the 9-point WFTA.
//
// The algorithm is optimized (?) for speed, not for small rounding errors or
// good readability.
//
// 36 additions, 11 multiplications
//
// Again this is very likely sub-optimal.
//
// The code is optimized to use a minimum number of temporary variables,
// so it should compile quite well even on 8-register Intel x86 processors.
// This makes the code quite obfuscated and very difficult to understand.
//
// References:
// [1] S. Winograd: "On Computing the Discrete Fourier Transform",
//     Mathematics of Computation, Volume 32, Number 141, January 1978,
//     Pages 175-199
*/

/*------------------------------------------------------------------*/
/*                                                                  */
/*    Function: Calculation of the inverse MDCT                     */
/*                                                                  */
/*------------------------------------------------------------------*/
/* used to be static without 3dnow - does that really matter? */
void dct36(real *inbuf,real *o1,real *o2,real *wintab,real *tsbuf)
{
#ifdef NEW_DCT9
  real tmp[18];
#endif

  {
    register 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];


#ifdef NEW_DCT9
#if 1
    {
     real t3;
     { 
      real t0, t1, t2;

      t0 = REAL_MUL(COS6_2, (in[8] + in[16] - in[4]));
      t1 = REAL_MUL(COS6_2, in[12]);

      t3 = in[0];
      t2 = t3 - t1 - t1;
      tmp[1] = tmp[7] = t2 - t0;
      tmp[4]          = t2 + t0 + t0;
      t3 += t1;

      t2 = REAL_MUL(COS6_1, (in[10] + in[14] - in[2]));
      tmp[1] -= t2;
      tmp[7] += t2;
     }
     {
      real t0, t1, t2;

      t0 = REAL_MUL(cos9[0], (in[4] + in[8] ));
      t1 = REAL_MUL(cos9[1], (in[8] - in[16]));
      t2 = REAL_MUL(cos9[2], (in[4] + in[16]));

      tmp[2] = tmp[6] = t3 - t0      - t2;
      tmp[0] = tmp[8] = t3 + t0 + t1;
      tmp[3] = tmp[5] = t3      - t1 + t2;
     }
    }
    {
      real t1, t2, t3;

      t1 = REAL_MUL(cos18[0], (in[2]  + in[10]));
      t2 = REAL_MUL(cos18[1], (in[10] - in[14]));
      t3 = REAL_MUL(COS6_1,    in[6]);

      {
        real t0 = t1 + t2 + t3;
        tmp[0] += t0;
        tmp[8] -= t0;
      }

      t2 -= t3;
      t1 -= t3;

      t3 = REAL_MUL(cos18[2], (in[2] + in[14]));

      t1 += t3;
      tmp[3] += t1;
      tmp[5] -= t1;

      t2 -= t3;
      tmp[2] += t2;
      tmp[6] -= t2;
    }

#else
    {
      real t0, t1, t2, t3, t4, t5, t6, t7;

      t1 = REAL_MUL(COS6_2, in[12]);
      t2 = REAL_MUL(COS6_2, (in[8] + in[16] - in[4]));

      t3 = in[0] + t1;
      t4 = in[0] - t1 - t1;
      t5     = t4 - t2;
      tmp[4] = t4 + t2 + t2;

      t0 = REAL_MUL(cos9[0], (in[4] + in[8]));
      t1 = REAL_MUL(cos9[1], (in[8] - in[16]));

      t2 = REAL_MUL(cos9[2], (in[4] + in[16]));

      t6 = t3 - t0 - t2;
      t0 += t3 + t1;
      t3 += t2 - t1;

      t2 = REAL_MUL(cos18[0], (in[2]  + in[10]));
      t4 = REAL_MUL(cos18[1], (in[10] - in[14]));
      t7 = REAL_MUL(COS6_1, in[6]);

      t1 = t2 + t4 + t7;
      tmp[0] = t0 + t1;
      tmp[8] = t0 - t1;
      t1 = REAL_MUL(cos18[2], (in[2] + in[14]));
      t2 += t1 - t7;

      tmp[3] = t3 + t2;
      t0 = REAL_MUL(COS6_1, (in[10] + in[14] - in[2]));
      tmp[5] = t3 - t2;

      t4 -= t1 + t7;

      tmp[1] = t5 - t0;
      tmp[7] = t5 + t0;
      tmp[2] = t6 + t4;
      tmp[6] = t6 - t4;
    }
#endif

    {
      real t0, t1, t2, t3, t4, t5, t6, t7;

      t1 = REAL_MUL(COS6_2, in[13]);
      t2 = REAL_MUL(COS6_2, (in[9] + in[17] - in[5]));

      t3 = in[1] + t1;
      t4 = in[1] - t1 - t1;
      t5 = t4 - t2;

      t0 = REAL_MUL(cos9[0], (in[5] + in[9]));
      t1 = REAL_MUL(cos9[1], (in[9] - in[17]));

      tmp[13] = REAL_MUL((t4 + t2 + t2), tfcos36[17-13]);
      t2 = REAL_MUL(cos9[2], (in[5] + in[17]));

      t6 = t3 - t0 - t2;
      t0 += t3 + t1;
      t3 += t2 - t1;

      t2 = REAL_MUL(cos18[0], (in[3]  + in[11]));
      t4 = REAL_MUL(cos18[1], (in[11] - in[15]));
      t7 = REAL_MUL(COS6_1, in[7]);

      t1 = t2 + t4 + t7;
      tmp[17] = REAL_MUL((t0 + t1), tfcos36[17-17]);
      tmp[9]  = REAL_MUL((t0 - t1), tfcos36[17-9]);
      t1 = REAL_MUL(cos18[2], (in[3] + in[15]));
      t2 += t1 - t7;

      tmp[14] = REAL_MUL((t3 + t2), tfcos36[17-14]);
      t0 = REAL_MUL(COS6_1, (in[11] + in[15] - in[3]));
      tmp[12] = REAL_MUL((t3 - t2), tfcos36[17-12]);

      t4 -= t1 + t7;

      tmp[16] = REAL_MUL((t5 - t0), tfcos36[17-16]);
      tmp[10] = REAL_MUL((t5 + t0), tfcos36[17-10]);
      tmp[15] = REAL_MUL((t6 + t4), tfcos36[17-15]);
      tmp[11] = REAL_MUL((t6 - t4), tfcos36[17-11]);
   }

#define MACRO(v) { \
    real tmpval; \
    tmpval = tmp[(v)] + tmp[17-(v)]; \
    out2[9+(v)] = REAL_MUL(tmpval, w[27+(v)]); \
    out2[8-(v)] = REAL_MUL(tmpval, w[26-(v)]); \
    tmpval = tmp[(v)] - tmp[17-(v)]; \
    ts[SBLIMIT*(8-(v))] = out1[8-(v)] + REAL_MUL(tmpval, w[8-(v)]); \
    ts[SBLIMIT*(9+(v))] = out1[9+(v)] + REAL_MUL(tmpval, w[9+(v)]); }

{
   register real *out2 = o2;
   register real *w = wintab;
   register real *out1 = o1;
   register real *ts = tsbuf;

   MACRO(0);
   MACRO(1);
   MACRO(2);
   MACRO(3);
   MACRO(4);
   MACRO(5);
   MACRO(6);
   MACRO(7);
   MACRO(8);
}

#else

  {

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

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

    real ta33,ta66,tb33,tb66;

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

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

      MACRO1(0);
      MACRO2(8);
    }

    {
      real tmp1a,tmp2a,tmp1b,tmp2b;
      tmp1a = REAL_MUL(( in[2*1+0] - in[2*5+0] - in[2*7+0] ), c[3]);
      tmp1b = REAL_MUL(( in[2*1+1] - in[2*5+1] - in[2*7+1] ), c[3]);
      tmp2a = REAL_MUL(( in[2*2+0] - in[2*4+0] - in[2*8+0] ), c[6]) - in[2*6+0] + in[2*0+0];
      tmp2b = REAL_MUL(( 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 =   REAL_MUL(in[2*1+0], c[5]) - ta33 - REAL_MUL(in[2*5+0], c[7]) + REAL_MUL(in[2*7+0], c[1]);
      tmp1b =   REAL_MUL(in[2*1+1], c[5]) - tb33 - REAL_MUL(in[2*5+1], c[7]) + REAL_MUL(in[2*7+1], c[1]);
      tmp2a = - REAL_MUL(in[2*2+0], c[8]) - REAL_MUL(in[2*4+0], c[2]) + ta66 + REAL_MUL(in[2*8+0], c[4]);
      tmp2b = - REAL_MUL(in[2*2+1], c[8]) - REAL_MUL(in[2*4+1], c[2]) + tb66 + REAL_MUL(in[2*8+1], c[4]);

      MACRO1(2);
      MACRO2(6);
    }

    {
      real tmp1a,tmp2a,tmp1b,tmp2b;
      tmp1a =   REAL_MUL(in[2*1+0], c[7]) - ta33 + REAL_MUL(in[2*5+0], c[1]) - REAL_MUL(in[2*7+0], c[5]);
      tmp1b =   REAL_MUL(in[2*1+1], c[7]) - tb33 + REAL_MUL(in[2*5+1], c[1]) - REAL_MUL(in[2*7+1], c[5]);
      tmp2a = - REAL_MUL(in[2*2+0], c[4]) + REAL_MUL(in[2*4+0], c[8]) + ta66 - REAL_MUL(in[2*8+0], c[2]);
      tmp2b = - REAL_MUL(in[2*2+1], c[4]) + REAL_MUL(in[2*4+1], c[8]) + tb66 - REAL_MUL(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 = REAL_MUL((in[2*0+1] - in[2*2+1] + in[2*4+1] - in[2*6+1] + in[2*8+1] ), tfcos36[4]);
		MACRO0(4);
	}
  }
#endif

  }
}

/*
 * new DCT12
 */
static void dct12(real *in,real *rawout1,real *rawout2,register real *wi,register 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 = REAL_MUL(in2, COS6_1); \
     in3 = REAL_MUL(in3, COS6_1); \

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


   {
     real in0,in1,in2,in3,in4,in5;
     register 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 = REAL_MUL((in1 - in5), tfcos12[1]);
         tmp0 = tmp1 + tmp2;
         tmp1 -= tmp2;
       }
       ts[(17-1)*SBLIMIT] = out1[17-1] + REAL_MUL(tmp0, wi[11-1]);
       ts[(12+1)*SBLIMIT] = out1[12+1] + REAL_MUL(tmp0, wi[6+1]);
       ts[(6 +1)*SBLIMIT] = out1[6 +1] + REAL_MUL(tmp1, wi[1]);
       ts[(11-1)*SBLIMIT] = out1[11-1] + REAL_MUL(tmp1, wi[5-1]);
     }

     DCT12_PART2

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

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

  in++;

  {
     real in0,in1,in2,in3,in4,in5;
     register real *out2 = rawout2;
 
     DCT12_PART1

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

     DCT12_PART2

     out2[5-0] = REAL_MUL(in2, wi[11-0]);
     out2[0+0] = REAL_MUL(in2, wi[6+0]);
     out2[0+2] = REAL_MUL(in3, wi[6+2]);
     out2[5-2] = REAL_MUL(in3, wi[11-2]);

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

  in++; 

  {
     real in0,in1,in2,in3,in4,in5;
     register 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 = REAL_MUL((in1 - in5), tfcos12[1]);
         tmp0 = tmp1 + tmp2;
         tmp1 -= tmp2;
       }
       out2[11-1] = REAL_MUL(tmp0, wi[11-1]);
       out2[6 +1] = REAL_MUL(tmp0, wi[6+1]);
       out2[0+1] += REAL_MUL(tmp1, wi[1]);
       out2[5-1] += REAL_MUL(tmp1, wi[5-1]);
     }

     DCT12_PART2

     out2[11-0] = REAL_MUL(in2, wi[11-0]);
     out2[6 +0] = REAL_MUL(in2, wi[6+0]);
     out2[6 +2] = REAL_MUL(in3, wi[6+2]);
     out2[11-2] = REAL_MUL(in3, wi[11-2]);

     out2[0+0] += REAL_MUL(in0, wi[0]);
     out2[5-0] += REAL_MUL(in0, wi[5-0]);
     out2[0+2] += REAL_MUL(in4, wi[2]);
     out2[5-2] += REAL_MUL(in4, wi[5-2]);
  }
}

/*
 * III_hybrid
 */
static void III_hybrid(real fsIn[SBLIMIT][SSLIMIT], real tsOut[SSLIMIT][SBLIMIT], int ch,struct gr_info_s *gr_info, mpg123_handle *fr)
{
   real (*block)[2][SBLIMIT*SSLIMIT] = fr->hybrid_block;
   int *blc = fr->hybrid_blc;

   real *tspnt = (real *) tsOut;
   real *rawout1,*rawout2;
   int bt,sb = 0;

   {
     int b = blc[ch];
     rawout1=block[b][ch];
     b=-b+1;
     rawout2=block[b][ch];
     blc[ch] = b;
   }
  
   if(gr_info->mixed_block_flag) {
     sb = 2;
     opt_dct36(fr)(fsIn[0],rawout1,rawout2,win[0],tspnt);
     opt_dct36(fr)(fsIn[1],rawout1+18,rawout2+18,win1[0],tspnt+1);
     rawout1 += 36; rawout2 += 36; tspnt += 2;
   }
 
   bt = gr_info->block_type;
   if(bt == 2) {
     for (; sb<gr_info->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<gr_info->maxb; sb+=2,tspnt+=2,rawout1+=36,rawout2+=36) {
       opt_dct36(fr)(fsIn[sb],rawout1,rawout2,win[bt],tspnt);
       opt_dct36(fr)(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++ = DOUBLE_TO_REAL(0.0);
     }
   }
}


/*
 * main layer3 handler
 */
int do_layer3(mpg123_handle *fr)
{
  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;
  int stereo = fr->stereo;
  int single = fr->single;
  int ms_stereo,i_stereo;
  int sfreq = fr->sampling_frequency;
  int stereo1,granules;

  if(stereo == 1) { /* stream is mono */
    stereo1 = 1;
    single = SINGLE_LEFT;
  }
  else if(single != SINGLE_STEREO) /* 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)>>1;
    i_stereo  = fr->mode_ext & 0x1;
  }
  else
    ms_stereo = i_stereo = 0;

  if(fr->lsf) {
    granules = 1;
  }
  else {
    granules = 2;
  }
  /* quick hack to keep the music playing */
  /* after having seen this nasty test file... */
  if(III_get_side_info(fr, &sideinfo,stereo,ms_stereo,sfreq,single))
  {
    error("bad frame - unable to get valid sideinfo");
    return clip;
  }

  set_pointer(fr,sideinfo.main_data_begin);

  for (gr=0;gr<granules;gr++) {
    ALIGNED(16) real hybridIn[2][SBLIMIT][SSLIMIT];
    ALIGNED(16) real hybridOut[2][SSLIMIT][SBLIMIT];

    {
      struct gr_info_s *gr_info = &(sideinfo.ch[0].gr[gr]);
      long part2bits;
      if(fr->lsf)
        part2bits = III_get_scale_factors_2(fr, scalefacs[0],gr_info,0);
      else
        part2bits = III_get_scale_factors_1(fr, scalefacs[0],gr_info,0,gr);

      if(III_dequantize_sample(fr, hybridIn[0], scalefacs[0],gr_info,sfreq,part2bits))
        return clip;
    }

    if(stereo == 2) {
      struct gr_info_s *gr_info = &(sideinfo.ch[1].gr[gr]);
      long part2bits;
      if(fr->lsf) 
        part2bits = III_get_scale_factors_2(fr, scalefacs[1],gr_info,i_stereo);
      else
        part2bits = III_get_scale_factors_1(fr, scalefacs[1],gr_info,1,gr);

      if(III_dequantize_sample(fr, hybridIn[1],scalefacs[1],gr_info,sfreq,part2bits))
          return clip;

      if(ms_stereo) {
        int i;
        int maxb = sideinfo.ch[0].gr[gr].maxb;
        if(sideinfo.ch[1].gr[gr].maxb > maxb)
            maxb = sideinfo.ch[1].gr[gr].maxb;
        for(i=0;i<SSLIMIT*maxb;i++) {
          real tmp0 = ((real *)hybridIn[0])[i];
          real tmp1 = ((real *)hybridIn[1])[i];
          ((real *)hybridIn[0])[i] = tmp0 + tmp1;
          ((real *)hybridIn[1])[i] = tmp0 - tmp1;
        }
      }

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

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

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

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

#ifdef OPT_I486
    if (fr->synth != opt_synth_1to1(fr) || single != SINGLE_STEREO) {
#endif
    for(ss=0;ss<SSLIMIT;ss++) {
      if(single != SINGLE_STEREO) {
        clip += (fr->synth_mono)(hybridOut[0][ss], fr);
      }
      else
      {
        clip += (fr->synth)(hybridOut[0][ss], 0, fr, 0);
        clip += (fr->synth)(hybridOut[1][ss], 1, fr, 1);
      }

    }
#ifdef OPT_I486
    } else {
      /* Only stereo, 16 bits benefit from the 486 optimization. */
      ss=0;
      while (ss < SSLIMIT) {
        int n;
        n=(fr->buffer.size - fr->buffer.fill) / (2*2*32);
        if (n > (SSLIMIT-ss)) n=SSLIMIT-ss;
        
        synth_1to1_486(hybridOut[0][ss], 0, fr, n);
        synth_1to1_486(hybridOut[1][ss], 1, fr, n);
        ss+=n;
        fr->buffer.fill+=(2*2*32)*n;
      }
    }
#endif
  }
  
  return clip;
}