decode.c

mpeg layerI II III, support window and linux

      }

   if (read_decoder_table(fi) != HTN) {
      fprintf(stderr,"decoder table read error\n");
      exit(4);
      }
huffman_initialized = TRUE;
}

III_hufman_decode(is, si, ch, gr, part2_start, fr_ps,fp,fp_capt)
long int is[SBLIMIT][SSLIMIT];
III_side_info_t *si;
int gr, ch, part2_start;
frame_params *fr_ps;
FILE *fp;
FILE *fp_capt;
{
   int i, x, y;
   int v, w;
   struct huffcodetab *h;
   int region1Start;
   int region2Start;
   int sfreq;
   int currentBit, grBits;
   my_gr_info *gi;
   int bt = (*si).ch[ch].gr[gr].window_switching_flag && ((*si).ch[ch].gr[gr].block_type == 2);

   gi = (my_gr_info *) &(*si).ch[ch].gr[gr];
   sfreq = fr_ps->header->sampling_frequency + (fr_ps->header->version * 3);
   initialize_huffman();

   /* Find region boundary for short block case. */

   if ( ((*si).ch[ch].gr[gr].window_switching_flag) &&
        ((*si).ch[ch].gr[gr].block_type == 2) ) {

      /* Region2. */
        region1Start = 36;  /* sfb[9/3]*3=36 */
        region2Start = 576; /* No Region2 for short block case. */
   }
   else {          /* Find region boundary for long block case. */

      region1Start = sfBandIndex[sfreq]
                           .l[(*si).ch[ch].gr[gr].region0_count + 1]; /* MI */
      region2Start = sfBandIndex[sfreq]
                              .l[(*si).ch[ch].gr[gr].region0_count +
                              (*si).ch[ch].gr[gr].region1_count + 2]; /* MI */
#ifdef  DEBUG_PRINT_SCREEN
#ifdef  DEBUG_HUFFMAN            
      printf("region1Start = %d\n",region1Start);
      printf("region2Start = %d\n",region2Start);
#endif
#endif      
      }


   grBits     = part2_start + (*si).ch[ch].gr[gr].part2_3_length;
   currentBit = hsstell();

   /* Read bigvalues area. */
   for (i=0; i<(*si).ch[ch].gr[gr].big_values*2; i+=2) {
      if      (i<region1Start) h = &ht[(*si).ch[ch].gr[gr].table_select[0]];
      else if (i<region2Start) h = &ht[(*si).ch[ch].gr[gr].table_select[1]];
           else                h = &ht[(*si).ch[ch].gr[gr].table_select[2]];
#ifdef  DEBUG_PRINT_SCREEN
#ifdef  DEBUG_HUFFMAN            
      printf("totbit = %d\n",hsstell()); 
#endif
#endif
      huffman_decoder(h, &x, &y, &v, &w,fp_capt);
      is[i/SSLIMIT][i%SSLIMIT] = x;
      is[(i+1)/SSLIMIT][(i+1)%SSLIMIT] = y;
#ifdef DEBUG_PRINT_SCREEN 
#ifdef DEBUG_HUFFMAN
        printf("totbit = %d\n",hsstell());
        printf("***************is[%d][%d] = %d\n",i/SSLIMIT,i%SSLIMIT,is[i/SSLIMIT][i%SSLIMIT]);
        printf("***************is[%d][%d] = %d\n",(i+1)/SSLIMIT,(i+1)%SSLIMIT,is[(i+1)/SSLIMIT][(i+1)%SSLIMIT]);
#endif
#endif 

      
      }

   grBits     = part2_start + (*si).ch[ch].gr[gr].part2_3_length;
   currentBit = hsstell();

   /* Read count1 area. */
   h = &ht[(*si).ch[ch].gr[gr].count1table_select+32];
   while ((hsstell() < part2_start + (*si).ch[ch].gr[gr].part2_3_length ) &&
     ( i < SSLIMIT*SBLIMIT )) {
#ifdef  DEBUG_PRINT_SCREEN
#ifdef  DEBUG_HUFFMAN            
      printf("totbit = %d\n",hsstell()); 
#endif
#endif       
      huffman_decoder(h, &x, &y, &v, &w,fp_capt);
       
      is[i/SSLIMIT][i%SSLIMIT] = v;
      is[(i+1)/SSLIMIT][(i+1)%SSLIMIT] = w;
      is[(i+2)/SSLIMIT][(i+2)%SSLIMIT] = x;
      is[(i+3)/SSLIMIT][(i+3)%SSLIMIT] = y;
#ifdef DEBUG_PRINT_SCREEN 
#ifdef DEBUG_HUFFMAN
        printf("totbit = %d\n",hsstell());
        printf("***************is[%d][%d] = %d\n",i/SSLIMIT,i%SSLIMIT,is[i/SSLIMIT][i%SSLIMIT]);
        printf("***************is[%d][%d] = %d\n",(i+1)/SSLIMIT,(i+1)%SSLIMIT,is[(i+1)/SSLIMIT][(i+1)%SSLIMIT]);
        printf("***************is[%d][%d] = %d\n",(i+2)/SSLIMIT,(i+2)%SSLIMIT,is[(i+2)/SSLIMIT][(i+2)%SSLIMIT]);
        printf("***************is[%d][%d] = %d\n",(i+3)/SSLIMIT,(i+3)%SSLIMIT,is[(i+3)/SSLIMIT][(i+3)%SSLIMIT]);   
#endif
#endif
      
      i += 4;
      }

   grBits     = part2_start + (*si).ch[ch].gr[gr].part2_3_length;
   currentBit = hsstell();

   if (hsstell() > part2_start + (*si).ch[ch].gr[gr].part2_3_length)
   {  i -=4;
      rewindNbits(hsstell()-part2_start - (*si).ch[ch].gr[gr].part2_3_length);
   }

   /* Dismiss stuffing Bits */
   grBits     = part2_start + (*si).ch[ch].gr[gr].part2_3_length;
   currentBit = hsstell();
   if ( currentBit < grBits )
      hgetbits( grBits - currentBit );

   /* Zero out rest. */
   for (; i<SSLIMIT*SBLIMIT; i++)
      is[i/SSLIMIT][i%SSLIMIT] = 0;
#ifdef DEBUG_PRINT     
#ifdef DEBUG_HUFFMAN
    for (i=0; i<SSLIMIT*SBLIMIT; i++)
    {
        fprintf(fp,"is[%d][%d] = %d\n",i/SSLIMIT,i%SSLIMIT,is[i/SSLIMIT][i%SSLIMIT]);
    }
#endif 
#endif

   
}


int pretab[22] = {0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,2,2,3,3,3,2,0};

void III_dequantize_sample(is,xr,scalefac,gr_info, ch,fr_ps,fp)
long int is[SBLIMIT][SSLIMIT];
double xr[SBLIMIT][SSLIMIT];
struct gr_info_s *gr_info;
III_scalefac_t *scalefac;
frame_params *fr_ps;
int ch;
FILE *fp;
{
   int ss,sb,cb=0,sfreq;
   int stereo = fr_ps->stereo;
   int next_cb_boundary, cb_begin, cb_width, sign;

   sfreq=fr_ps->header->sampling_frequency + (fr_ps->header->version * 3);

   /* choose correct scalefactor band per block type, initalize boundary */

   if (gr_info->window_switching_flag && (gr_info->block_type == 2) )
      if (gr_info->mixed_block_flag)
         next_cb_boundary=sfBandIndex[sfreq].l[1];  /* LONG blocks: 0,1,3 */
      else {
         next_cb_boundary=sfBandIndex[sfreq].s[1]*3; /* pure SHORT block */
    cb_width = sfBandIndex[sfreq].s[1];
    cb_begin = 0;
      }
   else
      next_cb_boundary=sfBandIndex[sfreq].l[1];  /* LONG blocks: 0,1,3 */

   /* apply formula per block type */

   for (sb=0 ; sb < SBLIMIT ; sb++){
      for (ss=0 ; ss < SSLIMIT ; ss++) {

         if ( (sb*18)+ss == next_cb_boundary)  { /* Adjust critical band boundary */
            if (gr_info->window_switching_flag && (gr_info->block_type == 2)) {
               if (gr_info->mixed_block_flag)  {
                  if (((sb*18)+ss) == sfBandIndex[sfreq].l[8])  {
                     next_cb_boundary=sfBandIndex[sfreq].s[4]*3;
                     cb = 3;
                     cb_width = sfBandIndex[sfreq].s[cb+1] -
                                sfBandIndex[sfreq].s[cb];
                     cb_begin = sfBandIndex[sfreq].s[cb]*3;
                  }
                  else if (((sb*18)+ss) < sfBandIndex[sfreq].l[8])
                     next_cb_boundary = sfBandIndex[sfreq].l[(++cb)+1];
                  else {
                     next_cb_boundary = sfBandIndex[sfreq].s[(++cb)+1]*3;
                     cb_width = sfBandIndex[sfreq].s[cb+1] -
                                    sfBandIndex[sfreq].s[cb];
                     cb_begin = sfBandIndex[sfreq].s[cb]*3;
                  }
               }
               else  {
                  next_cb_boundary = sfBandIndex[sfreq].s[(++cb)+1]*3;
                  cb_width = sfBandIndex[sfreq].s[cb+1] -
                               sfBandIndex[sfreq].s[cb];
                cb_begin = sfBandIndex[sfreq].s[cb]*3;
               }
            }
            else /* long blocks */
               next_cb_boundary = sfBandIndex[sfreq].l[(++cb)+1];
#ifdef DEBUG_PRINT_SCREEN
#ifdef DEBUG_REQUAN
                printf("***************************next_cb_start = %d\n",next_cb_boundary); 
               
#endif
#endif  
#ifdef DEBUG_PRINT_DETAIL
#ifdef DEBUG_REQUAN
                fprintf(fp,"***************************next_cb_start = %d\n",next_cb_boundary);
#endif
#endif

            
         }

         /* Compute overall (global) scaling. */

         xr[sb][ss] = pow( 2.0 , (0.25 * (gr_info->global_gain - 210.0)));

         /* Do long/short dependent scaling operations. */

         if (gr_info->window_switching_flag && (
            ((gr_info->block_type == 2) && (gr_info->mixed_block_flag == 0)) ||
            ((gr_info->block_type == 2) && gr_info->mixed_block_flag && (sb >= 2)) )) {

            xr[sb][ss] *= pow(2.0, 0.25 * -8.0 *
                    gr_info->subblock_gain[(((sb*18)+ss) - cb_begin)/cb_width]);
            xr[sb][ss] *= pow(2.0, 0.25 * -2.0 * (1.0+gr_info->scalefac_scale)
              * (*scalefac)[ch].s[(((sb*18)+ss) - cb_begin)/cb_width][cb]);
#ifdef DEBUG_PRINT_SCREEN
#ifdef DEBUG_REQUAN
                printf("***************************sb = %d, ss = %d, cb = %d\n",sb,ss,cb); 
                printf("gr_info->subblock_gain[%d] = %d\n",(((sb*18)+ss) - cb_begin)/cb_width,gr_info->subblock_gain[(((sb*18)+ss) - cb_begin)/cb_width]);
                printf("scalefac_multiplier = %f\n",0.25 * 2.0 * (1.0+gr_info->scalefac_scale));
                printf("scf[%d]->s[%d][%d] = %d\n",ch,(((sb*18)+ss) - cb_begin)/cb_width,cb,(*scalefac)[ch].s[(((sb*18)+ss) - cb_begin)/cb_width][cb]);
#endif
#endif  
#ifdef DEBUG_PRINT_DETAIL
#ifdef DEBUG_REQUAN
                fprintf(fp,"***************************sb = %d, ss = %d, cb = %d\n",sb,ss,cb); 
                fprintf(fp,"gr_info->subblock_gain[%d] = %d\n",(((sb*18)+ss) - cb_begin)/cb_width,gr_info->subblock_gain[(((sb*18)+ss) - cb_begin)/cb_width]);
                fprintf(fp,"scalefac_multiplier = %f\n",0.25 * 2.0 * (1.0+gr_info->scalefac_scale));
                fprintf(fp,"scf[%d]->s[%d][%d] = %d\n",ch,(((sb*18)+ss) - cb_begin)/cb_width,cb,(*scalefac)[ch].s[(((sb*18)+ss) - cb_begin)/cb_width][cb]);
#endif
#endif          
         }
         else {   /* LONG block types 0,1,3 & 1st 2 subbands of switched blocks */
            xr[sb][ss] *= pow(2.0, -0.5 * (1.0+gr_info->scalefac_scale)
                                        * ((*scalefac)[ch].l[cb]
                                        + gr_info->preflag * pretab[cb]));
#ifdef DEBUG_PRINT_SCREEN
#ifdef DEBUG_REQUAN
                printf("***************************sb = %d, ss = %d, cb = %d\n",sb,ss,cb);  
                printf("scalefac_multiplier = %f\n",0.5 * (1.0+gr_info->scalefac_scale));
                printf("scf[%d]->l[%d] = %d\n",ch,cb,(*scalefac)[ch].l[cb]);
                printf("preflag = %d\n",gr_info->preflag);
                printf("pretable[%d] = %d\n",cb,pretab[cb]); 
#endif
#endif  
#ifdef DEBUG_PRINT_DETAIL
#ifdef DEBUG_REQUAN
                fprintf(fp,"***************************sb = %d, ss = %d,cb = %d\n",sb,ss,cb); 
                fprintf(fp,"scalefac_multiplier = %f\n",0.5 * (1.0+gr_info->scalefac_scale));
                fprintf(fp,"scf[%d]->l[%d] = %d\n",ch,cb,(*scalefac)[ch].l[cb]);
                fprintf(fp,"preflag = %d\n",gr_info->preflag);
                fprintf(fp,"pretable[%d] = %d\n",cb,pretab[cb]); 
#endif
#endif            
         }

         /* Scale quantized value. */

         sign = (is[sb][ss]<0) ? 1 : 0;
         xr[sb][ss] *= pow( (double) abs(is[sb][ss]), ((double)4.0/3.0) );
         if (sign) xr[sb][ss] = -xr[sb][ss];
#ifdef DEBUG_PRINT_SCREEN
#ifdef DEBUG_REQUAN
            printf("is[%d][%d] = %d\n",sb,ss,is[sb][ss]); 
            printf("xr[%d][%d] = %f\n",sb,ss,xr[sb][ss]); 
#endif
#endif
#ifdef DEBUG_PRINT_DETAIL
#ifdef DEBUG_REQUAN
            fprintf(fp,"is[%d][%d] = %d ;xr[%d][%d] = %f\n",sb,ss,is[sb][ss],sb,ss,xr[sb][ss]);
#endif
#endif 
#ifdef DEBUG_PRINT
#ifdef DEBUG_REQUAN
            fprintf(fp,"%f\n",xr[sb][ss]);
#endif
#endif            

      }
   }   
}

III_reorder (xr, ro, gr_info, fr_ps,fp)
double xr[SBLIMIT][SSLIMIT];
double ro[SBLIMIT][SSLIMIT];
struct gr_info_s *gr_info;
frame_params *fr_ps;
FILE *fp;
{
   int sfreq;
   int sfb, sfb_start, sfb_lines;
   int sb, ss, window, freq, src_line, des_line;

   sfreq=fr_ps->header->sampling_frequency + (fr_ps->header->version * 3);

   for(sb=0;sb<SBLIMIT;sb++)
      for(ss=0;ss<SSLIMIT;ss++)
         ro[sb][ss] = 0;

   if (gr_info->window_switching_flag && (gr_info->block_type == 2)) {
      if (gr_info->mixed_block_flag) {
         /* NO REORDER FOR LOW 2 SUBBANDS */
         for (sb=0 ; sb < 2 ; sb++)
            for (ss=0 ; ss < SSLIMIT ; ss++) {
               ro[sb][ss] = xr[sb][ss];
            }
         /* REORDERING FOR REST SWITCHED SHORT */
         for(sfb=3,sfb_start=sfBandIndex[sfreq].s[3],
            sfb_lines=sfBandIndex[sfreq].s[4] - sfb_start;
            sfb < 13; sfb++,sfb_start=sfBandIndex[sfreq].s[sfb],
            (sfb_lines=sfBandIndex[sfreq].s[sfb+1] - sfb_start))
               for(window=0; window<3; window++)
                  for(freq=0;freq<sfb_lines;freq++) {
                     src_line = sfb_start*3 + window*sfb_lines + freq;
                     des_line = (sfb_start*3) + window + (freq*3);
                     ro[des_line/SSLIMIT][des_line%SSLIMIT] =
                                    xr[src_line/SSLIMIT][src_line%SSLIMIT];
               }
      }
      else {  /* pure short */
         for(sfb=0,sfb_start=0,sfb_lines=sfBandIndex[sfreq].s[1];
            sfb < 13; sfb++,sfb_start=sfBandIndex[sfreq].s[sfb],
            (sfb_lines=sfBandIndex[sfreq].s[sfb+1] - sfb_start))
               for(window=0; window<3; window++)
                  for(freq=0;freq<sfb_lines;freq++) {
                     src_line = sfb_start*3 + window*sfb_lines + freq;
                     des_line = (sfb_start*3) + window + (freq*3);
                     ro[des_line/SSLIMIT][des_line%SSLIMIT] =