VidDepacket.c

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#include <math.h>
#include "rcpcc_hg16.h"
#include "uep_rcpcc.h"

extern int debug;
static int ppx[4][8][4];

void Makeppx(int Rtype)
{
  int i, j, k;
  int step = 32- Rtype;
  int row = 0;
  while (Rtype >=0)
    {
      if (row == 0){
        for (i=0; i<8; i++)
          for (j=0; j< 4; j++)
            ppx[row][i][j] = px[Rtype][i][j];
      }
      else 
        {
          for (i=0; i<8; i++)
            for (j=0; j< 4; j++)
              ppx[row][i][j] = px[Rtype][i][j] - px[Rtype + step][i][j];
        }
      Rtype = Rtype - step;
      row ++;
    }
  
  if (debug >= 5) {
    printf("ppx\n");
    for (i=0; i< 4; i++){
      printf("row %d\n", i);
      for (j=0; j < 8; j++){ 
        for (k=0; k< 4; k++)
          printf("%d ", ppx[i][j][k]);
        if (j <=6)
          printf(", ");
      } 
      printf("\n ");
    }
  }
}

void GetRcpcBits(buf_rcpc *b1, int *rcpc_bits1, int *rcpc_bits2, int Rtype , int N)
{
  
  int j,i,k;
  int step = 32 - Rtype;
  int *temp_bits[4];
  int buff[8][4];
  int co[4];
  int co2 = 0;
  int new_Rtype = Rtype - step * ((b1->count) - 1) ;
  int loopmax; 

  ConvBytes2Bits(b1->block[ (b1->count) - 1], rcpc_bits1, N);
  if (debug >= 5)
                printf(" into GetRcpcBits\n");  
 
  /* don't loop to b1->count, use max of b1->count and max_arq(rtype)+1.  The 
     reason is that a bufrcpc structure may have inadvertantly gotten 
     an ARQ that exceeded its count for its rate type and we don't want 
     to use this information which will cause a crash */

  if (b1->count > max_arq(Rtype) + 1)
    loopmax = max_arq(Rtype) + 1;
  else 
    loopmax = b1->count;

  for (i=0; i<  loopmax; i++){
    temp_bits[i] = (int *) malloc(10 *  N * 8 *sizeof(int) );
    if (temp_bits[i] == NULL)
      printf("GetRcpcbits () - error can't malloc temp_bits[%d]\n",i);
 
    ConvBytes2Bits(b1->block[i], temp_bits[i], N);
    co[i] = 0;
  }
  
  while ( co2 <  N * 8 * loopmax ){
    for (i=0; i< 8; i++){
      for (j=0; j< 4; j++){
        buff[i][j]= 0;
        
        for (k=0; k< loopmax; k++)
          {
            if (ppx[k][i][j] ==1)
              {
                buff[i][j] = temp_bits[k][co[k]];
                co[k]++;
              }
          }
        if ((px[new_Rtype][i][j] == 1 ) &&( co2 <   N * 8 * (b1->count)) )
          {
            rcpc_bits2[co2] =  buff[i][j];
            co2++;
          }
      }
    }
  }

  if (debug >= 5)
                printf(" end of GetRcpcBits\n");
  for (i=0; i<  loopmax; i++){
    free(temp_bits[i]);
  }
}

unsigned char *DecodeVideoPacket(int Rtype, int N, buf_rcpc *b1, 
                                 int *CRC_flag, int *K, int CRCBytes, 
                                 int arq_type)
{
  int *out_bits;
  int i, j;
  int *rcpc_bits1;
  int *rcpc_bits2;
  int step  = 32 - Rtype;
  int new_Rtype;
  unsigned char *info_bytes;


  /* bits on the current row */
  rcpc_bits1= (int *)malloc(N * 8  *sizeof(int));  
  if (rcpc_bits1 == NULL) {
    printf("DecodeVideoPacket () - error can't malloc rcpc_bits1\n");
  }

  /* bits on all rows */
  rcpc_bits2= (int *)malloc(N * 8 * (b1->count) *sizeof(int)); 
  if (rcpc_bits2 == NULL) {
    printf("DecodeVideoPacket () - error can't malloc rcpc_bits2\n");
  }

  (*K)=rcpcc16_getK(Rtype,N,CRCBytes);

  info_bytes = (unsigned char *)calloc((*K)+CRCBytes, sizeof(unsigned char ));
  if (info_bytes == NULL)
    printf("DecodeVideoPacket () - error can't calloc info_bytes");
  out_bits = (int *)calloc( ( (*K)  + CRCBytes) * 8 + TAILBITS, sizeof(int) );
  if (out_bits == NULL)
    printf("DecodeVideoPacket () - error can't calloc out_bits\n");


  Makeppx(Rtype);
  
  GetRcpcBits(b1, rcpc_bits1, rcpc_bits2, Rtype, N );


  if ((b1->count) == 1) {  

    rcpcc16_decode(rcpc_bits1, out_bits, Rtype, N, ppx[0],CRCBytes);

    ConvBits2Bytes(out_bits, info_bytes, (*K)+CRCBytes);
    
    *CRC_flag = CheckCRC(info_bytes, (*K), CRCBytes);
    
  } else if ((b1->count) > 1)  { 

    /* 
     * Do Type I ARQ 
     */
    if((arq_type == 3) || (arq_type == 1)) {

      rcpcc16_decode(rcpc_bits1, out_bits, Rtype, N, ppx[b1->count - 1],CRCBytes);

      ConvBits2Bytes(out_bits, info_bytes, (*K)+CRCBytes);
      
      *CRC_flag = CheckCRC(info_bytes, (*K), CRCBytes);

    }
    /* 
     * Do Type II ARQ
     */
    if (((*CRC_flag == 0) && (arq_type == 3)) || (arq_type==2)) {
      for (i=0; i< ( (*K)  + CRCBytes) * 8 + TAILBITS ; i++)
        out_bits[i]= 0;
      
      new_Rtype = Rtype - step*( (b1->count) -1);
      
      rcpcc16_decode(rcpc_bits2, out_bits, new_Rtype,
                     (b1->count)*N, px[new_Rtype],CRCBytes);
      
      ConvBits2Bytes(out_bits, info_bytes, *K+CRCBytes);
      
      *CRC_flag = CheckCRC(info_bytes,  (*K), CRCBytes);

    }
  }


  free(out_bits);
  free(rcpc_bits1);
  free(rcpc_bits2);
  
  return info_bytes;
}

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