reactos/lib/3rdparty/libmpg123/dct64.c

   1 /*
   2         dct64.c: DCT64, the plain C version
   3
   4         copyright ?-2006 by the mpg123 project - free software under the terms of the LGPL 2.1
   5         see COPYING and AUTHORS files in distribution or http://mpg123.org
   6         initially written by Michael Hipp
   7 */
   8
   9 /*
  10  * Discrete Cosine Tansform (DCT) for subband synthesis
  11  *
  12  * -funroll-loops (for gcc) will remove the loops for better performance
  13  * using loops in the source-code enhances readabillity
  14  *
  15  *
  16  * TODO: write an optimized version for the down-sampling modes
  17  *       (in these modes the bands 16-31 (2:1) or 8-31 (4:1) are zero
  18  */
  19
  20 #include "mpg123lib_intern.h"
  21
  22 void dct64(real *out0,real *out1,real *samples)
  23 {
  24   real bufs[64];
  25
  26  {
  27   register int i,j;
  28   register real *b1,*b2,*bs,*costab;
  29
  30   b1 = samples;
  31   bs = bufs;
  32   costab = pnts[0]+16;
  33   b2 = b1 + 32;
  34
  35   for(i=15;i>=0;i--)
  36     *bs++ = (*b1++ + *--b2);
  37   for(i=15;i>=0;i--)
  38     *bs++ = REAL_MUL((*--b2 - *b1++), *--costab);
  39
  40   b1 = bufs;
  41   costab = pnts[1]+8;
  42   b2 = b1 + 16;
  43
  44   {
  45     for(i=7;i>=0;i--)
  46       *bs++ = (*b1++ + *--b2);
  47     for(i=7;i>=0;i--)
  48       *bs++ = REAL_MUL((*--b2 - *b1++), *--costab);
  49     b2 += 32;
  50     costab += 8;
  51     for(i=7;i>=0;i--)
  52       *bs++ = (*b1++ + *--b2);
  53     for(i=7;i>=0;i--)
  54       *bs++ = REAL_MUL((*b1++ - *--b2), *--costab);
  55     b2 += 32;
  56   }
  57
  58   bs = bufs;
  59   costab = pnts[2];
  60   b2 = b1 + 8;
  61
  62   for(j=2;j;j--)
  63   {
  64     for(i=3;i>=0;i--)
  65       *bs++ = (*b1++ + *--b2);
  66     for(i=3;i>=0;i--)
  67       *bs++ = REAL_MUL((*--b2 - *b1++), costab[i]);
  68     b2 += 16;
  69     for(i=3;i>=0;i--)
  70       *bs++ = (*b1++ + *--b2);
  71     for(i=3;i>=0;i--)
  72       *bs++ = REAL_MUL((*b1++ - *--b2), costab[i]);
  73     b2 += 16;
  74   }
  75
  76   b1 = bufs;
  77   costab = pnts[3];
  78   b2 = b1 + 4;
  79
  80   for(j=4;j;j--)
  81   {
  82     *bs++ = (*b1++ + *--b2);
  83     *bs++ = (*b1++ + *--b2);
  84     *bs++ = REAL_MUL((*--b2 - *b1++), costab[1]);
  85     *bs++ = REAL_MUL((*--b2 - *b1++), costab[0]);
  86     b2 += 8;
  87     *bs++ = (*b1++ + *--b2);
  88     *bs++ = (*b1++ + *--b2);
  89     *bs++ = REAL_MUL((*b1++ - *--b2), costab[1]);
  90     *bs++ = REAL_MUL((*b1++ - *--b2), costab[0]);
  91     b2 += 8;
  92   }
  93   bs = bufs;
  94   costab = pnts[4];
  95
  96   for(j=8;j;j--)
  97   {
  98     real v0,v1;
  99     v0=*b1++; v1 = *b1++;
 100     *bs++ = (v0 + v1);
 101     *bs++ = REAL_MUL((v0 - v1), (*costab));
 102     v0=*b1++; v1 = *b1++;
 103     *bs++ = (v0 + v1);
 104     *bs++ = REAL_MUL((v1 - v0), (*costab));
 105   }
 106
 107  }
 108
 109
 110  {
 111   register real *b1;
 112   register int i;
 113
 114   for(b1=bufs,i=8;i;i--,b1+=4)
 115     b1[2] += b1[3];
 116
 117   for(b1=bufs,i=4;i;i--,b1+=8)
 118   {
 119     b1[4] += b1[6];
 120     b1[6] += b1[5];
 121     b1[5] += b1[7];
 122   }
 123
 124   for(b1=bufs,i=2;i;i--,b1+=16)
 125   {
 126     b1[8]  += b1[12];
 127     b1[12] += b1[10];
 128     b1[10] += b1[14];
 129     b1[14] += b1[9];
 130     b1[9]  += b1[13];
 131     b1[13] += b1[11];
 132     b1[11] += b1[15];
 133   }
 134  }
 135
 136
 137   out0[0x10*16] = REAL_SCALE_DCT64(bufs[0]);
 138   out0[0x10*15] = REAL_SCALE_DCT64(bufs[16+0]  + bufs[16+8]);
 139   out0[0x10*14] = REAL_SCALE_DCT64(bufs[8]);
 140   out0[0x10*13] = REAL_SCALE_DCT64(bufs[16+8]  + bufs[16+4]);
 141   out0[0x10*12] = REAL_SCALE_DCT64(bufs[4]);
 142   out0[0x10*11] = REAL_SCALE_DCT64(bufs[16+4]  + bufs[16+12]);
 143   out0[0x10*10] = REAL_SCALE_DCT64(bufs[12]);
 144   out0[0x10* 9] = REAL_SCALE_DCT64(bufs[16+12] + bufs[16+2]);
 145   out0[0x10* 8] = REAL_SCALE_DCT64(bufs[2]);
 146   out0[0x10* 7] = REAL_SCALE_DCT64(bufs[16+2]  + bufs[16+10]);
 147   out0[0x10* 6] = REAL_SCALE_DCT64(bufs[10]);
 148   out0[0x10* 5] = REAL_SCALE_DCT64(bufs[16+10] + bufs[16+6]);
 149   out0[0x10* 4] = REAL_SCALE_DCT64(bufs[6]);
 150   out0[0x10* 3] = REAL_SCALE_DCT64(bufs[16+6]  + bufs[16+14]);
 151   out0[0x10* 2] = REAL_SCALE_DCT64(bufs[14]);
 152   out0[0x10* 1] = REAL_SCALE_DCT64(bufs[16+14] + bufs[16+1]);
 153   out0[0x10* 0] = REAL_SCALE_DCT64(bufs[1]);
 154
 155   out1[0x10* 0] = REAL_SCALE_DCT64(bufs[1]);
 156   out1[0x10* 1] = REAL_SCALE_DCT64(bufs[16+1]  + bufs[16+9]);
 157   out1[0x10* 2] = REAL_SCALE_DCT64(bufs[9]);
 158   out1[0x10* 3] = REAL_SCALE_DCT64(bufs[16+9]  + bufs[16+5]);
 159   out1[0x10* 4] = REAL_SCALE_DCT64(bufs[5]);
 160   out1[0x10* 5] = REAL_SCALE_DCT64(bufs[16+5]  + bufs[16+13]);
 161   out1[0x10* 6] = REAL_SCALE_DCT64(bufs[13]);
 162   out1[0x10* 7] = REAL_SCALE_DCT64(bufs[16+13] + bufs[16+3]);
 163   out1[0x10* 8] = REAL_SCALE_DCT64(bufs[3]);
 164   out1[0x10* 9] = REAL_SCALE_DCT64(bufs[16+3]  + bufs[16+11]);
 165   out1[0x10*10] = REAL_SCALE_DCT64(bufs[11]);
 166   out1[0x10*11] = REAL_SCALE_DCT64(bufs[16+11] + bufs[16+7]);
 167   out1[0x10*12] = REAL_SCALE_DCT64(bufs[7]);
 168   out1[0x10*13] = REAL_SCALE_DCT64(bufs[16+7]  + bufs[16+15]);
 169   out1[0x10*14] = REAL_SCALE_DCT64(bufs[15]);
 170   out1[0x10*15] = REAL_SCALE_DCT64(bufs[16+15]);
 171
 172 }
 173
 174