libmpeg3/audio/synthesizers.c

   1 #include "mpeg3private.h"
   2 #include "mpeg3protos.h"
   3 #include "tables.h"
   4
   5 #define WRITE_SAMPLE(samples, sum) \
   6 { \
   7         (*samples) = (sum); \
   8 }
   9
  10 int mpeg3audio_synth_stereo(mpeg3_layer_t *audio,
  11         float *bandPtr,
  12         int channel,
  13         float *out,
  14         int *pnt)
  15 {
  16         float *samples = out + *pnt;
  17     register float sum;
  18         float *b0, (*buf)[0x110];
  19         int bo1;
  20
  21         if(!channel)
  22         {
  23         audio->bo--;
  24         audio->bo &= 0xf;
  25         buf = audio->synth_stereo_buffs[0];
  26         }
  27         else
  28         {
  29         buf = audio->synth_stereo_buffs[1];
  30         }
  31
  32         if(audio->bo & 0x1)
  33         {
  34         b0 = buf[0];
  35         bo1 = audio->bo;
  36         mpeg3audio_dct64(buf[1] + ((audio->bo + 1) & 0xf), buf[0] + audio->bo, bandPtr);
  37         }
  38         else
  39         {
  40         b0 = buf[1];
  41         bo1 = audio->bo + 1;
  42         mpeg3audio_dct64(buf[0] + audio->bo, buf[1] + audio->bo + 1, bandPtr);
  43         }
  44
  45 /*printf("%f %f %f\n", buf[0][0], buf[1][0], bandPtr[0]); */
  46
  47         {
  48         int j;
  49         float *window = mpeg3_decwin + 16 - bo1;
  50
  51         for(j = 16; j; j--, b0 += 0x10, window += 0x20, samples++)
  52         {
  53                 sum  = window[0x0] * b0[0x0];
  54                 sum -= window[0x1] * b0[0x1];
  55                 sum += window[0x2] * b0[0x2];
  56                 sum -= window[0x3] * b0[0x3];
  57                 sum += window[0x4] * b0[0x4];
  58                 sum -= window[0x5] * b0[0x5];
  59                 sum += window[0x6] * b0[0x6];
  60                 sum -= window[0x7] * b0[0x7];
  61                 sum += window[0x8] * b0[0x8];
  62                 sum -= window[0x9] * b0[0x9];
  63                 sum += window[0xA] * b0[0xA];
  64                 sum -= window[0xB] * b0[0xB];
  65                 sum += window[0xC] * b0[0xC];
  66                 sum -= window[0xD] * b0[0xD];
  67                 sum += window[0xE] * b0[0xE];
  68                 sum -= window[0xF] * b0[0xF];
  69
  70                 WRITE_SAMPLE(samples, sum);
  71         }
  72
  73         sum  = window[0x0] * b0[0x0];
  74         sum += window[0x2] * b0[0x2];
  75         sum += window[0x4] * b0[0x4];
  76         sum += window[0x6] * b0[0x6];
  77         sum += window[0x8] * b0[0x8];
  78         sum += window[0xA] * b0[0xA];
  79         sum += window[0xC] * b0[0xC];
  80         sum += window[0xE] * b0[0xE];
  81         WRITE_SAMPLE(samples, sum);
  82         b0 -= 0x10;
  83                 window -= 0x20;
  84                 samples++;
  85         window += bo1 << 1;
  86
  87         for(j = 15; j; j--, b0 -= 0x10, window -= 0x20, samples++)
  88         {
  89                 sum = -window[-0x1] * b0[0x0];
  90                 sum -= window[-0x2] * b0[0x1];
  91                 sum -= window[-0x3] * b0[0x2];
  92                 sum -= window[-0x4] * b0[0x3];
  93                 sum -= window[-0x5] * b0[0x4];
  94                 sum -= window[-0x6] * b0[0x5];
  95                 sum -= window[-0x7] * b0[0x6];
  96                 sum -= window[-0x8] * b0[0x7];
  97                 sum -= window[-0x9] * b0[0x8];
  98                 sum -= window[-0xA] * b0[0x9];
  99                 sum -= window[-0xB] * b0[0xA];
 100                 sum -= window[-0xC] * b0[0xB];
 101                 sum -= window[-0xD] * b0[0xC];
 102                 sum -= window[-0xE] * b0[0xD];
 103                 sum -= window[-0xF] * b0[0xE];
 104                 sum -= window[-0x0] * b0[0xF];
 105
 106                 WRITE_SAMPLE(samples, sum);
 107         }
 108         }
 109         *pnt += 32;
 110
 111         return 0;
 112 }
 113
 114
 115
 116 /* Call this after every seek to reset the buffers */
 117 int mpeg3audio_reset_synths(mpeg3_layer_t *audio)
 118 {
 119         int i, j, k;
 120         for(i = 0; i < 2; i++)
 121         {
 122                 for(j = 0; j < 2; j++)
 123                 {
 124                         for(k = 0; k < 0x110; k++)
 125                         {
 126                                 audio->synth_stereo_buffs[i][j][k] = 0;
 127                         }
 128                 }
 129         }
 130         for(i = 0; i < 64; i++)
 131         {
 132                 audio->synth_mono_buff[i] = 0;
 133                 audio->layer2_scfsi_buf[i] = 0;
 134         }
 135         for(i = 0; i < 2; i++)
 136         {
 137                 for(j = 0; j < 2; j++)
 138                 {
 139                         for(k = 0; k < SBLIMIT * SSLIMIT; k++)
 140                         {
 141                                 audio->mp3_block[i][j][k] = 0;
 142                         }
 143                 }
 144         }
 145         audio->mp3_blc[0] = 0;
 146         audio->mp3_blc[1] = 0;
 147         return 0;
 148 }