Jemand

/* this is a butchered version of derf's theora-exp code */
void quant_tables_init(oc_quant_table *_quant[2][3], const th_quant_info *_qinfo){
  int          qti;
  int          pli;
  for(qti=0;qti<2;qti++)for(pli=0;pli<3;pli++){
    int qi;
    int qri;
    /*These simple checks help us improve cache coherency later.*/
    if(pli>0&&memcmp(_qinfo->qi_ranges[qti]+pli-1,
     _qinfo->qi_ranges[qti]+pli,sizeof(_qinfo->qi_ranges[qti][pli]))==0){
      _quant[qti][pli]=_quant[qti][pli-1];
      continue;
    }
    if(qti>0&&memcmp(_qinfo->qi_ranges[qti-1]+pli,
     _qinfo->qi_ranges[qti]+pli,sizeof(_qinfo->qi_ranges[qti][pli]))==0){
      _quant[qti][pli]=_quant[qti-1][pli];
      continue;
    }
    for(qi=qri=0;qri<=_qinfo->qi_ranges[qti][pli].nranges;qri++){
      th_quant_base base;
      ogg_uint32_t  q;
      int           qi_start;
      int           qi_end;
      int           ci;
      memcpy(base,_qinfo->qi_ranges[qti][pli].base_matrices[qri],
       sizeof(base));
      qi_start=qi;
      if(qri==_qinfo->qi_ranges[qti][pli].nranges)qi_end=qi+1;
      else qi_end=qi+_qinfo->qi_ranges[qti][pli].sizes[qri];
      for(;;){
        ogg_uint32_t qfac;
        /*In the original VP3.2 code, the rounding offset and the size of the
           dead zone around 0 were controlled by a "sharpness" parameter.
          The size of our dead zone is now controlled by the per-coefficient
           quality thresholds returned by our HVS module.
          We round down from a more accurate value when the quality of the
           reconstruction does not fall below our threshold and it saves bits.
          Hence, all of that VP3.2 code is gone from here, and the remaining
           floating point code has been implemented as equivalent integer code
           with exact precision.*/
        /*Scale DC the coefficient from the proper table.*/
        /*qfac=(ogg_uint32_t)_qinfo->dc_scale[qi]*base[0];*/
        qfac=base[0];
       
        /*q=(qfac/100)<<2;*/
        q=OC_CLAMPI(OC_DC_QUANT_MIN[qti],q,OC_QUANT_MAX);
        _quant[qti][pli][qi][0]=(ogg_uint16_t)q;
        /*Now scale AC coefficients from the proper table.*/
        for(ci=1;ci<64;ci++){
          /*q=((ogg_uint32_t)_qinfo->ac_scale[qi]*base[ci]/100)<<2;*/
          q=base[ci];
          q=OC_CLAMPI(OC_AC_QUANT_MIN[qti],q,OC_QUANT_MAX);
          _quant[qti][pli][qi][ci]=(ogg_uint16_t)q;
        }
        if(++qi>=qi_end)break;
        /*Interpolate the next base matrix.*/
        for(ci=0;ci<64;ci++){
          base[ci]=(unsigned char)(
           (2*((qi_end-qi)*_qinfo->qi_ranges[qti][pli].base_matrices[qri][ci]+
           (qi-qi_start)*_qinfo->qi_ranges[qti][pli].base_matrices[qri+1][ci])
           +_qinfo->qi_ranges[qti][pli].sizes[qri])/
           (2*_qinfo->qi_ranges[qti][pli].sizes[qri]));
        }
      }
    }
  }
}