video.c

Motion detection in matlab

	ParseReconBlock(i);
      } else {
	zero_block_flag = 1;
      }

      /* If macroblock is intra coded... */
      if (vid_stream->mblock.mb_intra) {
	ReconIMBlock(vid_stream, i);
      } else if (mb_motion_forw && mb_motion_back) {
	ReconBiMBlock(vid_stream, i, recon_right_for, recon_down_for,
		      recon_right_back, recon_down_back, zero_block_flag);
      } else if (mb_motion_forw || (vid_stream->picture.code_type == P_TYPE)) {
	ReconPMBlock(vid_stream, i, recon_right_for, recon_down_for,
		     zero_block_flag);
      } else if (mb_motion_back) {
	ReconBMBlock(vid_stream, i, recon_right_back, recon_down_back,
		     zero_block_flag);
      }
    }
    /* Kill the Chrominace blocks... */
    if ((vid_stream->mblock.mb_intra) || (vid_stream->mblock.cbp & 0x2)) {
        ParseAwayBlock(4);
    }
    if ((vid_stream->mblock.mb_intra) || (vid_stream->mblock.cbp & 0x1)) {
        ParseAwayBlock(5);
    }
  }
  else { 
    for (mask = 32, i = 0; i < 6; mask >>= 1, i++) {
	
      /* If block exists... */
      if ((vid_stream->mblock.mb_intra) || (vid_stream->mblock.cbp & mask)) {
	  zero_block_flag = 0;
	  ParseReconBlock(i);
      } else {
	  zero_block_flag = 1;
      }
      
      /* If macroblock is intra coded... */
      if (vid_stream->mblock.mb_intra) {
	  ReconIMBlock(vid_stream, i);
      } else if (mb_motion_forw && mb_motion_back) {
	  ReconBiMBlock(vid_stream, i, recon_right_for, recon_down_for,
			recon_right_back, recon_down_back, zero_block_flag);
      } else if (mb_motion_forw || (vid_stream->picture.code_type == P_TYPE)) {
	  ReconPMBlock(vid_stream, i, recon_right_for, recon_down_for,
		       zero_block_flag);
      } else if (mb_motion_back) {
	  ReconBMBlock(vid_stream, i, recon_right_back, recon_down_back,
		       zero_block_flag);
      
  
      }
    }
  }

  /* If D Type picture, flush marker bit. */
  if (vid_stream->picture.code_type == 4)
    flush_bits(1);

  /* If macroblock was intracoded, set macroblock past intra address. */
  if (vid_stream->mblock.mb_intra)
    vid_stream->mblock.past_intra_addr =
      vid_stream->mblock.mb_address;

#ifdef ANALYSIS
  *mbSizePtr += bitCountRead() - mbSizeCount;
#endif
  return PARSE_OK;
}



/*
 *--------------------------------------------------------------
 *
 * ReconIMBlock --
 *
 *	Reconstructs intra coded macroblock.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

static void
ReconIMBlock(VidStream *vid_stream, int bnum)
{
  int mb_row, mb_col, row, col, row_size, rr;
  unsigned char *dest;

  /* Calculate macroblock row and column from address. */

  mb_row = vid_stream->mblock.mb_address / vid_stream->mb_width;
  mb_col = vid_stream->mblock.mb_address % vid_stream->mb_width;


  /* If block is luminance block... */

  if (bnum < 4) {

    /* Calculate row and col values for upper left pixel of block. */

    row = mb_row * 16;
    col = mb_col * 16;
    if (bnum > 1)
      row += 8;
    if (bnum % 2)
      col += 8;

    /* Set dest to luminance plane of current pict image. */

    dest = vid_stream->current->luminance;

    /* Establish row size. */

    row_size = vid_stream->mb_width * 16;
  }
  /* Otherwise if block is Cr block... */

  else if (bnum == 4) {

    /* Set dest to Cr plane of current pict image. */

    dest = vid_stream->current->Cr;

    /* Establish row size. */

    row_size = vid_stream->mb_width * 8;

    /* Calculate row,col for upper left pixel of block. */

    row = mb_row * 8;
    col = mb_col * 8;
  }
  /* Otherwise block is Cb block, and ... */

  else {

    /* Set dest to Cb plane of current pict image. */

    dest = vid_stream->current->Cb;

    /* Establish row size. */

    row_size = vid_stream->mb_width * 8;

    /* Calculate row,col for upper left pixel value of block. */

    row = mb_row * 8;
    col = mb_col * 8;
  }

  /*
   * For each pixel in block, set to cropped reconstructed value from inverse
   * dct.
   */
  {
    short *sp = &vid_stream->block.dct_recon[0][0];
    unsigned char *cm = cropTbl + MAX_NEG_CROP;
    dest += row * row_size + col;
    for (rr = 0; rr < 4; rr++, sp += 16, dest += row_size) {
      dest[0] = cm[sp[0]];
      assertCrop(sp[0]);
      dest[1] = cm[sp[1]];
      assertCrop(sp[1]);
      dest[2] = cm[sp[2]];
      assertCrop(sp[2]);
      dest[3] = cm[sp[3]];
      assertCrop(sp[3]);
      dest[4] = cm[sp[4]];
      assertCrop(sp[4]);
      dest[5] = cm[sp[5]];
      assertCrop(sp[5]);
      dest[6] = cm[sp[6]];
      assertCrop(sp[6]);
      dest[7] = cm[sp[7]];
      assertCrop(sp[7]);

      dest += row_size;
      dest[0] = cm[sp[8]];
      assertCrop(sp[8]);
      dest[1] = cm[sp[9]];
      assertCrop(sp[9]);
      dest[2] = cm[sp[10]];
      assertCrop(sp[10]);
      dest[3] = cm[sp[11]];
      assertCrop(sp[11]);
      dest[4] = cm[sp[12]];
      assertCrop(sp[12]);
      dest[5] = cm[sp[13]];
      assertCrop(sp[13]);
      dest[6] = cm[sp[14]];
      assertCrop(sp[14]);
      dest[7] = cm[sp[15]];
      assertCrop(sp[15]);
    }
  }
}



/*
 *--------------------------------------------------------------
 *
 * ReconPMBlock --
 *
 *	Reconstructs forward predicted macroblocks.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      None.
 *
 *--------------------------------------------------------------
 */

static void
ReconPMBlock(VidStream *vid_stream,
	     int bnum,
	     int recon_right_for,
	     int recon_down_for,
	     int zflag)
{
  int mb_row, mb_col, row, col, row_size, rr;
  unsigned char *dest, *past;
  static int right_for, down_for, right_half_for, down_half_for;
  unsigned char *rindex1, *rindex2;
  unsigned char *index;
  short int *blockvals;

#ifdef LOOSE_MPEG
  int maxx, maxy;
  int illegalBlock = 0;
  int row_start, row_end, rfirst, rlast, col_start, col_end, cfirst, clast;
#endif

  /* Calculate macroblock row and column from address. */

  mb_row = vid_stream->mblock.mb_address / vid_stream->mb_width;
  mb_col = vid_stream->mblock.mb_address % vid_stream->mb_width;

  if (bnum < 4) {

    /* Calculate right_for, down_for motion vectors. */

    right_for = recon_right_for >> 1;
    down_for = recon_down_for >> 1;
    right_half_for = recon_right_for & 0x1;
    down_half_for = recon_down_for & 0x1;

    /* Set dest to luminance plane of current pict image. */

    dest = vid_stream->current->luminance;

    if (vid_stream->picture.code_type == B_TYPE) {
      if (vid_stream->past != NULL)
	past = vid_stream->past->luminance;
    } else {

      /* Set predicitive frame to current future frame. */

      if (vid_stream->future != NULL)
	past = vid_stream->future->luminance;
    }

    /* Establish row size. */

    row_size = vid_stream->mb_width << 4;

    /* Calculate row,col of upper left pixel in block. */

    row = mb_row << 4;
    col = mb_col << 4;
    if (bnum > 1)
      row += 8;
    if (bnum % 2)
      col += 8;

#ifdef LOOSE_MPEG
    /* Check for block illegality. */

    maxx = lmaxx; maxy = lmaxy;

    if (row + down_for + 7 > maxy) illegalBlock |= 0x4;
    else if (row + down_for < 0)  illegalBlock |= 0x1;
    
    if (col + right_for + 7 > maxx) illegalBlock |= 0x2;
    else if (col + right_for < 0) illegalBlock |= 0x8;

#endif
  }
  /* Otherwise, block is NOT luminance block, ... */

  else {

    /* Construct motion vectors. */

    recon_right_for /= 2;
    recon_down_for /= 2;
    right_for = recon_right_for >> 1;
    down_for = recon_down_for >> 1;
    right_half_for = recon_right_for & 0x1;
    down_half_for = recon_down_for & 0x1;

    /* Establish row size. */

    row_size = vid_stream->mb_width << 3;

    /* Calculate row,col of upper left pixel in block. */

    row = mb_row << 3;
    col = mb_col << 3;

#ifdef LOOSE_MPEG
    /* Check for block illegality. */

    maxx = cmaxx; maxy = cmaxy;

    if (row + down_for  + 7 > maxy) illegalBlock |= 0x4;
    else if (row + down_for < 0) illegalBlock |= 0x1;

    if (col + right_for  + 7 > maxx) illegalBlock  |= 0x2;
    else if (col + right_for < 0) illegalBlock |= 0x8;

#endif

    /* If block is Cr block... */

    if (bnum == 4) {

      /* Set dest to Cr plane of current pict image. */

      dest = vid_stream->current->Cr;

      if (vid_stream->picture.code_type == B_TYPE) {

	if (vid_stream->past != NULL)
	  past = vid_stream->past->Cr;
      } else {
	if (vid_stream->future != NULL)
	  past = vid_stream->future->Cr;
      }
    }
    /* Otherwise, block is Cb block... */

    else {

      /* Set dest to Cb plane of current pict image. */

      dest = vid_stream->current->Cb;

      if (vid_stream->picture.code_type == B_TYPE) {
	if (vid_stream->past != NULL)
	  past = vid_stream->past->Cb;
      } else {
	if (vid_stream->future != NULL)
	  past = vid_stream->future->Cb;
      }
    }
  }

  /* For each pixel in block... */

#ifdef LOOSE_MPEG

  if (illegalBlock) {
    if (illegalBlock & 0x1) {
      row_start = 0;
      row_end = row+down_for+8;
      rfirst = rlast = 8 - row_end;
    }
    else if (illegalBlock & 0x4) {
      row_start = row + down_for;
      row_end = maxy+1;
      rlast = row_end - row_start - 1;
      rfirst = 0;
    }
    else {
      row_start = row+down_for;
      row_end = row_start+8;
      rfirst = 0;
    }

    if (illegalBlock & 0x8) {
      col_start = 0;
      col_end = col + right_for + 8;
      cfirst = clast = 8 - col_end;
    }
    else if (illegalBlock & 0x2) {
      col_start = col + right_for;
      col_end = maxx + 1;
      clast = col_end - col_start - 1;
      cfirst = 0;
    }
    else {
      col_start = col + right_for;
      col_end = col_start + 8;
      cfirst = 0;
    }

    for (rr = row_start; rr < row_end; rr++) {
      rindex1 = past + (rr * row_size) + col_start;
      index = dest + ((row + rfirst) * row_size) + col + cfirst;
      for (cc = col_start; cc < col_end; cc++) {
	*index++ = *rindex1++;
      }
    }

    if (illegalBlock & 0x1) {
      for (rr = rlast -1; rr >=0; rr--) {
	index = dest + ((row + rr) * row_size) + col;
	rindex1 = dest + ((row + rlast) * row_size) + col;
	for (cc = 0; cc < 8; cc ++) {
	  *index++ = *rindex1++;
	}
      }
    }
    else if (illegalBlock & 0x4) {
      for (rr = rlast+1; rr < 8; rr++) {
	index = dest + ((row + rr) * row_size) + col;
	rindex1 = dest + ((row + rlast) * row_size) + col;
	for (cc = 0; cc < 8; cc ++) {
	  *index++ = *rindex1++;
	}
      }
    }

    if (illegalBlock & 0x2) {
      for (cc = clast+1; cc < 8; cc++) {
	index = dest + (row * row_size) + (col + cc);
	rindex1 = dest + (row * row_size) + (col + clast);
	for (rr = 0; rr < 8; rr++) {
	  *index = *rindex1;
	  index += row_size;
	  rindex1 += row_size;
	}
      }
    }
    else if (illegalBlock & 0x8) {
      for (cc = clast-1; cc >= 0; cc--) {
	index = dest + (row * row_size) + (col + cc);
	rindex1 = dest + (row * row_size) + (col + clast);
	for (rr = 0; rr < 8; rr++) {
	  *index = *rindex1;
	  index += row_size;
	  rindex1 += row_size;
	}
      }
    }

    if (!zflag) {
      for (rr = 0; rr < 8; rr++) {
	index = dest + (row*row_size) + col;
	blockvals = &(vid_stream->block.dct_recon[rr][0]);
	index[0] += blockvals[0];
	index[1] += blockvals[1];
	index[2] += blockvals[2];
	index[3] += blockvals[3];
	index[4] += blockvals[4];
	index[5] += blockvals[5];
	index[6] += blockvals[6];
	index[7] += blockvals[7];
      }
    }
  }
  else {

#endif

    index = dest + (row * row_size) + col;
    rindex1 = past + (row + down_for) * row_size + col + right_for;
    
    blockvals = &(vid_stream->block.dct_recon[0][0]);
    
    /*
     * Calculate predictive pixel value based on motion vectors and copy to
     * dest plane.
     */
    
    if ((!down_half_for) && (!right_half_for)) {
      unsigned char *cm = cropTbl + MAX_NEG_CROP;
      if (!zflag)
	for (rr = 0; rr < 4; rr++) {
	  index[0] = cm[(int) rindex1[0] + (int) blockvals[0]];
	  index[1] = cm[(int) rindex1[1] + (int) blockvals[1]];
	  index[2] = cm[(int)