layer3.cpp

VC++视频开发实例集锦(包括“远程视频监控”"语音识别系统"等13个经典例子)

   { { 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) 
    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(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 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 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};

/**
 *
 **/

static int III_dequantize_sample(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;



  {
    int bv       = gr_info->big_values;
    int region1  = gr_info->region1start;
    int region2  = gr_info->region2start;

    l3 = ((576>>1)-bv)>>1;   

    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) {


  
	int i,max[4];
    int step=0,lwin=0,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;

      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;
          while((y=*val++)<0) {
            if (get1bit())
              val -= y;
            part2remain--;
          }
          x = y >> 4;
          y &= 0xf;
        }
        if(x == 15) {
          max[lwin] = cb;
          part2remain -= h->linbits+1;
          x += getbits(h->linbits);
          if(get1bit())
            *xrpnt = -ispow[x] * v;
          else
            *xrpnt =  ispow[x] * v;
        }
        else if(x) {
          max[lwin] = cb;
          if(get1bit())
            *xrpnt = -ispow[x] * v;
          else
            *xrpnt =  ispow[x] * v;
          part2remain--;
        }
        else
          *xrpnt = 0.0;
        xrpnt += step;
        if(y == 15) {
          max[lwin] = cb;
          part2remain -= h->linbits+1;
          y += getbits(h->linbits);
          if(get1bit())
            *xrpnt = -ispow[y] * v;
          else
            *xrpnt =  ispow[y] * v;
        }
        else if(y) {
          max[lwin] = cb;
          if(get1bit())
            *xrpnt = -ispow[y] * v;
          else
            *xrpnt =  ispow[y] * v;
          part2remain--;
        }
        else
          *xrpnt = 0.0;
        xrpnt += step;
      }
    }




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

      while((a=*val++)<0) {
        part2remain--;
        if(part2remain < 0) {
          part2remain++;
          a = 0;
          break;
        }
        if (get1bit())
          val -= a;
      }

      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;
          part2remain--;
          if(part2remain < 0) {
            part2remain++;
            break;
          }
          if(get1bit()) 
            *xrpnt = -v;
          else
            *xrpnt = v;
        }
        else
          *xrpnt = 0.0;
        xrpnt += step;
      }
    }



    while( m < me ) {
      if(!mc) {
        mc = *m++;
        xrpnt = ((real *) xr) + *m++;
        if( (*m++) == 3)
          step = 1;
        else
          step = 3;
        m++; /* cb */
      }
      mc--;
      *xrpnt = 0.0;
      xrpnt += step;
      *xrpnt = 0.0;
      xrpnt += step;

    }




    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 ? shortLimit[sfreq][rmax] : longLimit[sfreq][max[3]+1];
    }

  }
  else {



    int *pretab = gr_info->preflag ? pretab1 : pretab2;
    int i,max = -1;
    int cb = 0;
    register int *m = map[sfreq][2];
    register real v = 0.0;
    register int mc = 0;
#if 0
    me = mapend[sfreq][2];
#endif



    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++;
          v = gr_info->pow2gain[((*scf++) + (*pretab++)) << shift];
          cb = *m++;
        }
        {
          register short *val = h->table;
          while((y=*val++)<0) {
            if (get1bit())
              val -= y;
            part2remain--;
          }
          x = y >> 4;
          y &= 0xf;
        }
        if (x == 15) {
          max = cb;
          part2remain -= h->linbits+1;
          x += getbits(h->linbits);
          if(get1bit())
            *xrpnt++ = -ispow[x] * v;
          else
            *xrpnt++ =  ispow[x] * v;
        }
        else if(x) {
          max = cb;
          if(get1bit())
            *xrpnt++ = -ispow[x] * v;
          else
            *xrpnt++ =  ispow[x] * v;
          part2remain--;
        }
        else
          *xrpnt++ = 0.0;

        if (y == 15) {
          max = cb;
          part2remain -= h->linbits+1;
          y += getbits(h->linbits);
          if(get1bit())
            *xrpnt++ = -ispow[y] * v;
          else
            *xrpnt++ =  ispow[y] * v;
        }
        else if(y) {
          max = cb;
          if(get1bit())
            *xrpnt++ = -ispow[y] * v;
          else
            *xrpnt++ =  ispow[y] * v;
          part2remain--;
        }
        else
          *xrpnt++ = 0.0;
      }
    }



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



      while((a=*val++)<0) {
        part2remain--;
        if(part2remain < 0) {
          part2remain++;
          a = 0;
          break;
        }
        if (get1bit())
          val -= a;
      }




      for(i=0;i<4;i++) {
        if(!(i & 1)) {
          if(!mc) {
        
		    
			mc = *m++;
            cb = *m++;


				v = gr_info->pow2gain[((*scf++) + (*pretab++)) << shift];
         
			}
          mc--;
        }



        if ( (a & (0x8>>i)) ) {
          max = cb;
          part2remain--;
          if(part2remain < 0) {
            part2remain++;
            break;
          }
          if(get1bit())
            *xrpnt++ = -v;
          else
            *xrpnt++ = v;
        }
        else
          *xrpnt++ = 0.0;
      }
    }


    for(i=(&xr[SBLIMIT][0]-xrpnt)>>1;i;i--) {
      *xrpnt++ = 0.0;
      *xrpnt++ = 0.0;
    }

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

  while( part2remain > 16 ) {
    getbits(16); 
    part2remain -= 16;
  }




  if(part2remain > 0)
    getbits(part2remain);
  else if(part2remain < 0) {
    return 1;
  }
  return 0;
}



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;
      struct bandInfoStruct *bi = &bandInfo[sfreq];
      real *tab1,*tab2;

      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;
        }
      }

      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++) 
         {
             
           int is_p,sb,idx,sfb = gr_info->maxband[lwin];  
           if(sfb > 3)
             do_l = 0;

           for(;sfb<12;sfb++)
           {
             is_p = scalefac[sfb*3+lwin-gr_info->mixed_block_flag]; 
             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] = v * t1;
                 xr[1][idx] = v * t2;
               }
             }
           }

#if 1

           is_p = scalefac[11*3+lwin-gr_info->mixed_block_flag]; 
           sb = bi->shortDiff[12];
           idx = bi->shortIdx[12] + lwin;
#else
           is_p = scalefac[10*3+lwin-gr_info->mixed_block_flag]; 
           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] = v * t1;
               xr[1][idx] = v * t2;
             }
           }
         } 

         if (do_l)
         {

           int sfb = gr_info->maxbandl;
           int idx = bi->longIdx[sfb];

           for ( ; sfb<8; sfb++ )
           {
             int sb = bi->longDiff[sfb];
             int is_p = scalefac[sfb]; 
             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] = v * t1;
                 xr[1][idx] = v * t2;