block.c

网络MPEG4IP流媒体开发源代码

    }
  }

  for (i=0;i<4;i++)
  {
    for (j=0;j<4;j++)
      M5[j]=M4[i][j];

    M6[0]=(M5[0]+M5[2])*13;
    M6[1]=(M5[0]-M5[2])*13;
    M6[2]= M5[1]*7 -M5[3]*17;
    M6[3]= M5[1]*17+M5[3]*7;

    for (j=0;j<2;j++)
    {
      j1=3-j;
      M0[0][i][0][j] = ((M6[j]+M6[j1])/8) *JQ[quant_set][1];
      M0[0][i][0][j1]= ((M6[j]-M6[j1])/8) *JQ[quant_set][1];
    }
  }
  for (j=0;j<4;j++)
  {
    for (i=0;i<4;i++)
    {
      M0[0][i][0][j] = 3 * M0[0][i][0][j]/256;
    }
  }

  // AC invers trans/quant for MB
  img->kac=0;
  for (jj=0;jj<4;jj++)
  {
    for (ii=0;ii<4;ii++)
    {
      run=-1;
      scan_pos=0;
#ifndef NO_RDQUANT
      for (coeff_ctr=1;coeff_ctr<16;coeff_ctr++) // set in AC coeff
      {
        i=SNGL_SCAN[coeff_ctr][0];
        j=SNGL_SCAN[coeff_ctr][1];
        coeff[coeff_ctr-1]=M0[i][ii][j][jj];
      }
      rd_quant(QUANT_LUMA_AC,coeff);

      for (coeff_ctr=1;coeff_ctr<16;coeff_ctr++) // set in AC coeff
      {
        i=SNGL_SCAN[coeff_ctr][0];
        j=SNGL_SCAN[coeff_ctr][1];
        run++;

        level=abs(coeff[coeff_ctr-1]);

        if (level != 0)
        {
          img->kac=1;
          img->cof[ii][jj][scan_pos][0][0]=sign(level,M0[i][ii][j][jj]);
          img->cof[ii][jj][scan_pos][1][0]=run;
          ++scan_pos;
          run=-1;
        }
        M0[i][ii][j][jj]=sign(level*JQ[quant_set][1],M0[i][ii][j][jj]);
      }
      img->cof[ii][jj][scan_pos][0][0]=0;
#endif
#ifdef NO_RDQUANT
      for (coeff_ctr=1;coeff_ctr<16;coeff_ctr++) // set in AC coeff
      {
        i=SNGL_SCAN[coeff_ctr][0];
        j=SNGL_SCAN[coeff_ctr][1];
        run++;

        level= ( abs( M0[i][ii][j][jj]) * JQ[quant_set][0]+qp_const)/JQQ1;

        if (level != 0)
        {
          img->kac=1;
          img->cof[ii][jj][scan_pos][0][0]=sign(level,M0[i][ii][j][jj]);
          img->cof[ii][jj][scan_pos][1][0]=run;
          ++scan_pos;
          run=-1;
        }
        M0[i][ii][j][jj]=sign(level*JQ[quant_set][1],M0[i][ii][j][jj]);
      }
      img->cof[ii][jj][scan_pos][0][0]=0;
#endif


      // IDCT horizontal

      for (j=0;j<4;j++)
      {
        for (i=0;i<4;i++)
        {
          M5[i]=M0[i][ii][j][jj];
        }

        M6[0]=(M5[0]+M5[2])*13;
        M6[1]=(M5[0]-M5[2])*13;
        M6[2]=M5[1]*7 -M5[3]*17;
        M6[3]=M5[1]*17+M5[3]*7;

        for (i=0;i<2;i++)
        {
          i1=3-i;
          M0[i][ii][j][jj] =M6[i]+M6[i1];
          M0[i1][ii][j][jj]=M6[i]-M6[i1];
        }
      }

      // vert
      for (i=0;i<4;i++)
      {
        for (j=0;j<4;j++)
          M5[j]=M0[i][ii][j][jj];

        M6[0]=(M5[0]+M5[2])*13;
        M6[1]=(M5[0]-M5[2])*13;
        M6[2]=M5[1]*7 -M5[3]*17;
        M6[3]=M5[1]*17+M5[3]*7;

        for (j=0;j<2;j++)
        {
          j1=3-j;
          M0[i][ii][ j][jj]=M6[j]+M6[j1];
          M0[i][ii][j1][jj]=M6[j]-M6[j1];

        }
      }

    }
  }

  for (j=0;j<16;j++)
  {
    for (i=0;i<16;i++)
    {
      M1[i][j]=M0[i%4][i/4][j%4][j/4];
    }
  }

  for (j=0;j<16;j++)
    for (i=0;i<16;i++)
      imgY[img->pix_y+j][img->pix_x+i]=min(255,max(0,(M1[i][j]+img->mprr_2[new_intra_mode][j][i]*JQQ1+JQQ2)/JQQ1));

}


/*!
 ************************************************************************
 * \brief
 *    Intra prediction for chroma.  There is only one prediction mode,
 *    corresponding to 'DC prediction' for luma. However,since 2x2 transform
 *    of DC levels are used,all predictions are made from neighbouring MBs.
 *    Prediction also depends on whether the block is at a frame edge.
 *
 *  \para Input:
 *     Starting point of current chroma macro block image posision
 *
 *  \para Output:
 *     8x8 array with DC intra chroma prediction and diff array
 ************************************************************************
 */
void intrapred_chroma(int img_c_x,int img_c_y,int uv)
{
  int s[2][2],s0,s1,s2,s3;
  int i,j;

  int mb_nr = img->current_mb_nr;
  int mb_width = img->width/16;
  int mb_available_up = (img_c_y/BLOCK_SIZE == 0) ? 0 : (img->slice_numbers[mb_nr] == img->slice_numbers[mb_nr-mb_width]);
  int mb_available_left = (img_c_x/BLOCK_SIZE == 0) ? 0 : (img->slice_numbers[mb_nr] == img->slice_numbers[mb_nr-1]);
  if(input->UseConstrainedIntraPred)
  {
    if (mb_available_up && (img->intra_mb[mb_nr-mb_width] ==0))
      mb_available_up = 0;
    if (mb_available_left && (img->intra_mb[mb_nr-1] ==0))
      mb_available_left = 0;
  }
  s0=s1=s2=s3=0;          // reset counters

  for (i=0; i < BLOCK_SIZE; i++)
  {
    if(mb_available_up)
    {
      s0 += imgUV[uv][img_c_y-1][img_c_x+i];
      s1 += imgUV[uv][img_c_y-1][img_c_x+i+BLOCK_SIZE];
    }
    if(mb_available_left)
    {
      s2 += imgUV[uv][img_c_y+i][img_c_x-1];
      s3 += imgUV[uv][img_c_y+i+BLOCK_SIZE][img_c_x-1];
    }
  }

  if(mb_available_up && mb_available_left)
  {
    s[0][0]=(s0+s2+4)/(2*BLOCK_SIZE);
    s[1][0]=(s1+2)/BLOCK_SIZE;
    s[0][1]=(s3+2)/BLOCK_SIZE;
    s[1][1]=(s1+s3+4)/(2*BLOCK_SIZE);
  }
  else
    if(mb_available_up && !mb_available_left)
    {
      s[0][0]=(s0+2)/BLOCK_SIZE;
      s[1][0]=(s1+2)/BLOCK_SIZE;
      s[0][1]=(s0+2)/BLOCK_SIZE;
      s[1][1]=(s1+2)/BLOCK_SIZE;
    }
    else
      if(!mb_available_up && mb_available_left)
      {
        s[0][0]=(s2+2)/BLOCK_SIZE;
        s[1][0]=(s2+2)/BLOCK_SIZE;
        s[0][1]=(s3+2)/BLOCK_SIZE;
        s[1][1]=(s3+2)/BLOCK_SIZE;
      }
      else
        if(!mb_available_up && !mb_available_left)
        {
          s[0][0]=128;
          s[1][0]=128;
          s[0][1]=128;
          s[1][1]=128;
        }
  for (j=0; j < MB_BLOCK_SIZE/2; j++)
  {
    for (i=0; i < MB_BLOCK_SIZE/2; i++)
    {
      img->mpr[i][j]=s[i/BLOCK_SIZE][j/BLOCK_SIZE];
      img->m7[i][j]=imgUV_org[uv][img_c_y+j][img_c_x+i]-img->mpr[i][j];
    }
  }
}


/*!
 ************************************************************************
 * \brief
 *    The routine performs transform,quantization,inverse transform, adds the diff.
 *    to the prediction and writes the result to the decoded luma frame. Includes the
 *    RD constrained quantization also.
 *
 * \para Input:
 *    block_x,block_y: Block position inside a macro block (0,4,8,12).
 *
 * \para Output_
 *    nonzero: 0 if no levels are nonzero.  1 if there are nonzero levels.             \n
 *    coeff_cost: Counter for nonzero coefficients, used to discard expencive levels.
 ************************************************************************
 */
int dct_luma(int block_x,int block_y,int *coeff_cost)
{
  int sign(int a,int b);

  int i,j,i1,j1,ilev,m5[4],m6[4],coeff_ctr,scan_loop_ctr;
  int qp_const,pos_x,pos_y,quant_set,level,scan_pos,run;
  int nonzero;
  int idx;

  int scan_mode;
  int loop_rep;
#ifndef NO_RDQUANT
  int coeff[16];
#endif

  if (img->type == INTRA_IMG)
    qp_const=JQQ3;    // intra
  else
    qp_const=JQQ4;    // inter

  pos_x=block_x/BLOCK_SIZE;
  pos_y=block_y/BLOCK_SIZE;

  //  Horizontal transform

  for (j=0; j < BLOCK_SIZE; j++)
  {
    for (i=0; i < 2; i++)
    {
      i1=3-i;
      m5[i]=img->m7[i][j]+img->m7[i1][j];
      m5[i1]=img->m7[i][j]-img->m7[i1][j];
    }
    img->m7[0][j]=(m5[0]+m5[1])*13;
    img->m7[2][j]=(m5[0]-m5[1])*13;
    img->m7[1][j]=m5[3]*17+m5[2]*7;
    img->m7[3][j]=m5[3]*7-m5[2]*17;
  }

  //  Vertival transform

  for (i=0; i < BLOCK_SIZE; i++)
  {
    for (j=0; j < 2; j++)
    {
      j1=3-j;
      m5[j]=img->m7[i][j]+img->m7[i][j1];
      m5[j1]=img->m7[i][j]-img->m7[i][j1];
    }
    img->m7[i][0]=(m5[0]+m5[1])*13;
    img->m7[i][2]=(m5[0]-m5[1])*13;
    img->m7[i][1]=m5[3]*17+m5[2]*7;
    img->m7[i][3]=m5[3]*7-m5[2]*17;
  }

  // Quant

  quant_set=img->qp;
  nonzero=FALSE;

  if (img->imod == INTRA_MB_OLD && img->qp < 24)
  {
    scan_mode=DOUBLE_SCAN;
    loop_rep=2;
    idx=1;
  }
  else
  {
    scan_mode=SINGLE_SCAN;
    loop_rep=1;
    idx=0;
  }

#ifndef NO_RDQUANT
  for(scan_loop_ctr=0;scan_loop_ctr<loop_rep;scan_loop_ctr++) // 2 times if double scan, 1 normal scan
  {
    for (coeff_ctr=0;coeff_ctr < 16/loop_rep;coeff_ctr++)     // 8 times if double scan, 16 normal scan
    {
      if (scan_mode==DOUBLE_SCAN)
      {
        i=DBL_SCAN[coeff_ctr][0][scan_loop_ctr];
        j=DBL_SCAN[coeff_ctr][1][scan_loop_ctr];
      }
      else
      {
        i=SNGL_SCAN[coeff_ctr][0];
        j=SNGL_SCAN[coeff_ctr][1];
      }
      coeff[coeff_ctr]=img->m7[i][j];
    }
    if (scan_mode==DOUBLE_SCAN)
      rd_quant(QUANT_LUMA_DBL,coeff);
    else
      rd_quant(QUANT_LUMA_SNG,coeff);

    run=-1;
    scan_pos=scan_loop_ctr*9;   // for double scan; set first or second scan posision
    for (coeff_ctr=0; coeff_ctr<16/loop_rep; coeff_ctr++)
    {
      if (scan_mode==DOUBLE_SCAN)
      {
        i=DBL_SCAN[coeff_ctr][0][scan_loop_ctr];
        j=DBL_SCAN[coeff_ctr][1][scan_loop_ctr];
      }
      else
      {
        i=SNGL_SCAN[coeff_ctr][0];
        j=SNGL_SCAN[coeff_ctr][1];
      }
      run++;
      ilev=0;

      level= absm(coeff[coeff_ctr]);
      if (level != 0)
      {
        nonzero=TRUE;
        if (level > 1)
          *coeff_cost += MAX_VALUE;                // set high cost, shall not be discarded
        else
          *coeff_cost += COEFF_COST[run];
        img->cof[pos_x][pos_y][scan_pos][0][scan_mode]=sign(level,img->m7[i][j]);
        img->cof[pos_x][pos_y][scan_pos][1][scan_mode]=run;
        ++scan_pos;
        run=-1;                     // reset zero level counter
        ilev=level*JQ[quant_set][1];
      }
      img->m7[i][j]=sign(ilev,img->m7[i][j]);
    }
    img->cof[pos_x][pos_y][scan_pos][0][scan_mode]=0;  // end of block
  }
#endif

#ifdef NO_RDQUANT
  for(scan_loop_ctr=0;scan_loop_ctr<loop_rep;scan_loop_ctr++) // 2 times if double scan, 1 normal scan
  {
  run=-1;
  scan_pos=scan_loop_ctr*9;

    for (coeff_ctr=0;coeff_ctr < 16/loop_rep;coeff_ctr++)     // 8 times if double scan, 16 normal scan
    {
      if (scan_mode==DOUBLE_SCAN)
      {
        i=DBL_SCAN[coeff_ctr][0][scan_loop_ctr];
        j=DBL_SCAN[coeff_ctr][1][scan_loop_ctr];
      }
      else
      {
        i=SNGL_SCAN[coeff_ctr][0];
        j=SNGL_SCAN[coeff_ctr][1];
      }

      run++;
      ilev=0;
      level = (abs (img->m7[i][j]) * JQ[quant_set][0] +qp_const) / JQQ1;

      if (level != 0)
      {
        nonzero=TRUE;
        if (level > 1)
          *coeff_cost += MAX_VALUE;                // set high cost, shall not be discarded
        else
          *coeff_cost += COEFF_COST[run];
        img->cof[pos_x][pos_y][scan_pos][0][scan_mode]=sign(level,img->m7[i][j]);
        img->cof[pos_x][pos_y][scan_pos][1][scan_mode]=run;
        ++scan_pos;
        run=-1;                     // reset zero level counter
        ilev=level*JQ[quant_set][1];
      }
      img->m7[i][j]=sign(ilev,img->m7[i][j]);
    }
    img->cof[pos_x][pos_y][scan_pos][0][scan_mode]=0;  // end of block
  }
#endif




  //     IDCT.
  //     horizontal

  for (j=0; j < BLOCK_SIZE; j++)
  {
    for (i=0; i < BLOCK_SIZE; i++)
    {
      m5[i]=img->m7[i][j];
    }
    m6[0]=(m5[0]+m5[2])*13;
    m6[1]=(m5[0]-m5[2])*13;
    m6[2]=m5[1]*7-m5[3]*17;
    m6[3]=m5[1]*17+m5[3]*7;

    for (i=0; i < 2; i++)
    {
      i1=3-i;
      img->m7[i][j]=m6[i]+m6[i1];
      img->m7[i1][j]=m6[i]-m6[i1];
    }
  }

  //  vertical

  for (i=0; i < BLOCK_SIZE; i++)
  {
    for (j=0; j < BLOCK_SIZE; j++)
    {
      m5[j]=img->m7[i][j];
    }
    m6[0]=(m5[0]+m5[2])*13;
    m6[1]=(m5[0]-m5[2])*13;
    m6[2]=m5[1]*7-m5[3]*17;
    m6[3]=m5[1]*17+m5[3]*7;

    for (j=0; j < 2; j++)
    {
      j1=3-j;
      img->m7[i][j] =min(255,max(0,(m6[j]+m6[j1]+img->mpr[i+block_x][j+block_y] *JQQ1+JQQ2)/JQQ1));
      img->m7[i][j1]=min(255,max(0,(m6[j]-m6[j1]+img->mpr[i+block_x][j1+block_y] *JQQ1+JQQ2)/JQQ1));
    }
  }

  //  Decoded block moved to frame memory

  for (j=0; j < BLOCK_SIZE; j++)
    for (i=0; i < BLOCK_SIZE; i++)
      imgY[img->pix_y+block_y+j][img->pix_x+block_x+i]=img->m7[i][j];


  return nonzero;
}