block.c

linux下将各类格式图片转换工具

 *===========================================================================*/
void
AddMotionBlock(block, prev, by, bx, my, mx)
    Block block;
    uint8 **prev;
    int by;
    int bx;
    int my;
    int mx;
{
    int	    fy, fx;
    int	    x, y;
    boolean xHalf, yHalf;

    xHalf = (ABS(mx) % 2 == 1);
    yHalf = (ABS(my) % 2 == 1);

    MOTION_TO_FRAME_COORD(by, bx, (my/2), (mx/2), fy, fx);

    if ( xHalf && yHalf ) {
	/* really should be fy+y-1 and fy+y so do (fy-1)+y = fy+y-1 and
	   (fy-1)+y+1 = fy+y
	 */
	if ( my < 0 ) {
	    fy--;
	}
	if ( mx < 0 ) {
	    fx--;
	}

	for ( y = 0; y < 8; y++ ) {
	    for ( x = 0; x < 8; x++ ) {
		block[y][x] += (prev[fy+y][fx+x]+prev[fy+y][fx+x+1]+
				    prev[fy+y+1][fx+x]+prev[fy+y+1][fx+x+1]+2)>>2;
	    }
	}
    } else if ( xHalf ) {
	if ( mx < 0 ) {
	    fx--;
	}

	for ( y = 0; y < 8; y++ ) {
	    for ( x = 0; x < 8; x++ ) {
		block[y][x] += (prev[fy+y][fx+x]+prev[fy+y][fx+x+1]+1)>>1;
	    }
	}
    } else if ( yHalf ) {
	if ( my < 0 ) {
	    fy--;
	}

	for ( y = 0; y < 8; y++ ) {
	    for ( x = 0; x < 8; x++ ) {
		block[y][x] += (prev[fy+y][fx+x]+prev[fy+y+1][fx+x]+1)>>1;
	    }
	}
    } else {
	for ( y = 0; y < 8; y++ ) {
	    for ( x = 0; x < 8; x++ ) {
		block[y][x] += (int16)prev[fy+y][fx+x];
	    }
	}
    }
}


/*===========================================================================*
 *
 * AddBMotionBlock
 *
 *	adds the motion-compensated B-frame block to the given block
 *
 * RETURNS:	block modified
 *
 * SIDE EFFECTS:    none
 *
 * PRECONDITIONS:  motion vectors MUST be valid
 *
 *===========================================================================*/
void
AddBMotionBlock(block, prev, next, by, bx, mode, fmy, fmx, bmy, bmx)
    Block block;
    uint8 **prev;
    uint8 **next;
    int by;
    int bx;
    int	mode;
    int fmy;
    int fmx;
    int bmy;
    int bmx;
{
    int	    x, y;
    Block   prevBlock, nextBlock;

    if ( mode == MOTION_FORWARD ) {
	AddMotionBlock(block, prev, by, bx, fmy, fmx);
    } else if ( mode == MOTION_BACKWARD ) {
	AddMotionBlock(block, next, by, bx, bmy, bmx);
    } else {
	ComputeMotionBlock(prev, by, bx, fmy, fmx, prevBlock);
	ComputeMotionBlock(next, by, bx, bmy, bmx, nextBlock);

	for ( y = 0; y < 8; y++ ) {
	    for ( x = 0; x < 8; x++ ) {
		block[y][x] += (prevBlock[y][x]+nextBlock[y][x]+1)/2;
	    }
	}
    }
}


/*===========================================================================*
 *
 * BlockToData
 *
 *	copies the given block into the appropriate data area
 *
 * RETURNS:	data modified
 *
 * SIDE EFFECTS:    none
 *
 *===========================================================================*/
void
BlockToData(data, block, by, bx)
    uint8 **data;
    Block block;
    int by;
    int bx;
{
    register int x, y;
    register int fy, fx;
    register int16    blockItem;

    BLOCK_TO_FRAME_COORD(by, bx, fy, fx);

    for ( y = 0; y < 8; y++ ) {
	for ( x = 0; x < 8; x++ ) {
	    blockItem = block[y][x];
	    data[fy+y][fx+x] = TRUNCATE_UINT8(blockItem);
	}
    }
}


/*===========================================================================*
 *
 * BlockifyFrame
 *
 *	copies data into appropriate blocks
 *
 * RETURNS:	mf modified
 *
 * SIDE EFFECTS:    none
 *
 * NOTES:  probably shouldn't be in this file
 *
 *===========================================================================*/
void
BlockifyFrame(framePtr)
    MpegFrame *framePtr;
{
    register int dctx, dcty;
    register int x, y;
    register int bx, by;
    register int fy, fx;
    register int16  *destPtr;
    register uint8  *srcPtr;
    register int16  *destPtr2;
    register uint8  *srcPtr2;
    Block   *blockPtr;
    Block   *blockPtr2;

    dctx = Fsize_x / DCTSIZE;
    dcty = Fsize_y / DCTSIZE;

    /*
     * copy y data into y_blocks
     */
    for (by = 0; by < dcty; by++) {
	fy = by*DCTSIZE;
	for (bx = 0; bx < dctx; bx++) {
	    fx = bx*DCTSIZE;
	    blockPtr = (Block *) &(framePtr->y_blocks[by][bx][0][0]);
	    for (y = 0; y < DCTSIZE; y++) {
		destPtr = &((*blockPtr)[y][0]);
		srcPtr = &(framePtr->orig_y[fy+y][fx]);
		for (x = 0; x < DCTSIZE; x++) {
		    destPtr[x] = srcPtr[x];
		}
	    }
	}
    }

    /*
     * copy cr/cb data into cr/cb_blocks
     */
    for (by = 0; by < (dcty >> 1); by++) {
	fy = by*DCTSIZE;
	for (bx = 0; bx < (dctx >> 1); bx++) {
	    fx = bx*DCTSIZE;
	    blockPtr = (Block *) &(framePtr->cr_blocks[by][bx][0][0]);
	    blockPtr2 = (Block *) &(framePtr->cb_blocks[by][bx][0][0]);
	    for (y = 0; y < DCTSIZE; y++) {
		destPtr = &((*blockPtr)[y][0]);
		srcPtr = &(framePtr->orig_cr[fy+y][fx]);
		destPtr2 = &((*blockPtr2)[y][0]);
		srcPtr2 = &(framePtr->orig_cb[fy+y][fx]);
		for (x = 0; x < DCTSIZE; x++) {
		    destPtr[x] = srcPtr[x];
		    destPtr2[x] = srcPtr2[x];
		}
	    }
	}
    }
}


/*===========================================================================*
 *									     *
 * UNUSED PROCEDURES							     *
 *									     *
 *	The following procedures are all unused by the encoder		     *
 *									     *
 *	They are listed here for your convenience.  You might want to use    *
 *	them if you experiment with different search techniques		     *
 *									     *
 *===========================================================================*/

#ifdef UNUSED_PROCEDURES

/* this procedure calculates the subsampled motion block (obviously)
 *
 * for speed, this procedure is probably not called anywhere (it is
 * incorporated directly into LumDiffA, LumDiffB, etc.
 *
 * but leave it here anyway for clarity
 *
 * (startY, startX) = (0,0) for A....(0,1) for B...(1,0) for C...(1,1) for D
 *  
 */
void
ComputeSubSampledMotionLumBlock(prevFrame, by, bx, my, mx, motionBlock,
				startY, startX)
    MpegFrame *prevFrame;
    int by;
    int bx;
    int my;
    int mx;
    LumBlock motionBlock;
    int startY;
    int startX;
{
    register uint8 *across;
    register int32 *macross;
    register int32 *lastx;
    register int y;
    uint8 **prev;
    int    fy, fx;
    boolean xHalf, yHalf;

    xHalf = (ABS(mx) % 2 == 1);
    yHalf = (ABS(my) % 2 == 1);

    MOTION_TO_FRAME_COORD(by, bx, my/2, mx/2, fy, fx);

    if ( xHalf ) {
	if ( mx < 0 ) {
	    fx--;
	}

	if ( yHalf ) {
	    if ( my < 0 ) {
		fy--;
	    }
	    
	    prev = prevFrame->halfBoth;
	} else {
	    prev = prevFrame->halfX;
	}
    } else if ( yHalf ) {
	if ( my < 0 ) {
	    fy--;
	}

	prev = prevFrame->halfY;
    } else {
	prev = prevFrame->ref_y;
    }

    for ( y = startY; y < 16; y += 2 ) {
	across = &(prev[fy+y][fx+startX]);
	macross = &(motionBlock[y][startX]);
	lastx = &(motionBlock[y][16]);
	while ( macross < lastx ) {
	    (*macross) = (*across);
	    across += 2;
	    macross += 2;
	}
    }

    /* this is what's really going on in slow motion:
     *
     *	for ( y = startY; y < 16; y += 2 )
     *	    for ( x = startX; x < 16; x += 2 )
     *		motionBlock[y][x] = prev[fy+y][fx+x];
     *
     */
}


/*===========================================================================*
 *
 * LumMotionErrorSubSampled
 *
 *	return the MAD of the currentBlock and the motion-compensated block,
 *	subsampled 4:1 with given starting coordinates (startY, startX)
 *
 * RETURNS:	the MAD
 *
 * SIDE EFFECTS:    none
 *
 * PRECONDITIONS:  motion vector MUST be valid
 *
 * NOTES:  this procedure is never called.  Instead, see subsample.c.  This
 *         procedure is provided only for possible use in extensions
 *
 *===========================================================================*/
int32
LumMotionErrorSubSampled(currentBlock, prevFrame, by, bx, my, mx, startY,
			 startX)
    LumBlock currentBlock;
    MpegFrame *prevFrame;
    int by;
    int bx;
    int my;
    int mx;
    int startY;
    int startX;
{
    register int32    diff = 0;	    /* max value of diff is 255*256 = 65280 */
    register int32 localDiff;
    register int32 *cacross;
    register uint8 *macross;
    register int32 *lastx;
    register int y;
    uint8 **prev;
    int    fy, fx;
    boolean xHalf, yHalf;

    xHalf = (ABS(mx) % 2 == 1);
    yHalf = (ABS(my) % 2 == 1);

    MOTION_TO_FRAME_COORD(by, bx, my/2, mx/2, fy, fx);

    if ( xHalf ) {
	if ( mx < 0 ) {
	    fx--;
	}

	if ( yHalf ) {
	    if ( my < 0 ) {
		fy--;
	    }
	    
	    prev = prevFrame->halfBoth;
	} else {
	    prev = prevFrame->halfX;
	}
    } else if ( yHalf ) {
	if ( my < 0 ) {
	    fy--;
	}

	prev = prevFrame->halfY;
    } else {
	prev = prevFrame->ref_y;
    }

    for ( y = startY; y < 16; y += 2 ) {
	macross = &(prev[fy+y][fx+startX]);
	cacross = &(currentBlock[y][startX]);
	lastx = &(currentBlock[y][16]);
	while ( cacross < lastx ) {
	    localDiff = (*cacross)-(*macross);
	    diff += ABS(localDiff);
	    macross += 2;
	    cacross += 2;
	}
    }

    /* this is what's really happening:
     *
     *	ComputeSubSampledMotionLumBlock(prevFrame, by, bx, my, mx,
     *					lumMotionBlock, startY, startX);
     *
     *	for ( y = startY; y < 16; y += 2 )
     *	    for ( x = startX; x < 16; x += 2 )
     *	    {
     *	     	localDiff = currentBlock[y][x] - lumMotionBlock[y][x];
     *		diff += ABS(localDiff);
     *	    }
     *
     */

    return (int32)diff;
}


#endif /* UNUSED_PROCEDURES */