Function III_overlap

modules/data/mp3/libmad/layer3.c:2297–2340

NAME: III_overlap() DESCRIPTION: perform overlap-add of windowed IMDCT outputs */

   DESCRIPTION:	perform overlap-add of windowed IMDCT outputs
*/
static
void III_overlap(mad_fixed_t const output[36], mad_fixed_t overlap[18],
                 mad_fixed_t sample[18][32], unsigned int sb)
{
  unsigned int i;
  stack(__FUNCTION__, __FILE__, __LINE__);

# if defined(ASO_INTERLEAVE2)
  {
    register mad_fixed_t tmp1, tmp2;

    tmp1 = overlap[0];
    tmp2 = overlap[1];

    for (i = 0; i < 16; i += 2) {
      sample[i + 0][sb] = output[i + 0 +  0] + tmp1;
      overlap[i + 0]    = output[i + 0 + 18];
      tmp1 = overlap[i + 2];

      sample[i + 1][sb] = output[i + 1 +  0] + tmp2;
      overlap[i + 1]    = output[i + 1 + 18];
      tmp2 = overlap[i + 3];
    }

    sample[16][sb] = output[16 +  0] + tmp1;
    overlap[16]    = output[16 + 18];
    sample[17][sb] = output[17 +  0] + tmp2;
    overlap[17]    = output[17 + 18];
  }
# elif 0
  for (i = 0; i < 18; i += 2) {
    sample[i + 0][sb] = output[i + 0 +  0] + overlap[i + 0];
    overlap[i + 0]    = output[i + 0 + 18];

    sample[i + 1][sb] = output[i + 1 +  0] + overlap[i + 1];
    overlap[i + 1]    = output[i + 1 + 18];
  }
# else
  for (i = 0; i < 18; ++i) {
    sample[i][sb] = output[i +  0] + overlap[i];
    overlap[i]    = output[i + 18];
  }
# endif
}

/*
   NAME:	III_overlap_z()