motion_est.c

mpeg4代码,比较具体

					   const uint8_t * const pRefH,
					   const uint8_t * const pRefV,
					   const uint8_t * const pRefHV,
					   const uint8_t * const cur,
					   const int x,
					   const int y,
					   const int start_xi,
					   const int start_yi,
					   int iMinSAD,
					   VECTOR * const currMV,
					   const int center_x,
					   const int center_y,
					   const int32_t min_dx,
					   const int32_t max_dx,
					   const int32_t min_dy,
					   const int32_t max_dy,
					   const int32_t iEdgedWidth,
					   const int32_t iDiamondSize,
					   const int32_t iFcode,
					   const int32_t iQuant,
					   int iDirection)
{

	int32_t iSAD;
	int start_x = start_xi, start_y = start_yi;

/* directions: 1 - left (x-1); 2 - right (x+1), 4 - up (y-1); 8 - down (y+1) */

	if (iDirection) {
		CHECK_MV8_CANDIDATE(start_x - iDiamondSize, start_y);
		CHECK_MV8_CANDIDATE(start_x + iDiamondSize, start_y);
		CHECK_MV8_CANDIDATE(start_x, start_y - iDiamondSize);
		CHECK_MV8_CANDIDATE(start_x, start_y + iDiamondSize);
	} else {
		int bDirection = 1 + 2 + 4 + 8;

		do {
			iDirection = 0;
			if (bDirection & 1)	/*we only want to check left if we came from the right (our last motion was to the left, up-left or down-left) */
				CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize, start_y, 1);

			if (bDirection & 2)
				CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize, start_y, 2);

			if (bDirection & 4)
				CHECK_MV8_CANDIDATE_DIR(start_x, start_y - iDiamondSize, 4);

			if (bDirection & 8)
				CHECK_MV8_CANDIDATE_DIR(start_x, start_y + iDiamondSize, 8);

			/* now we're doing diagonal checks near our candidate */

			if (iDirection)		/*checking if anything found */
			{
				bDirection = iDirection;
				iDirection = 0;
				start_x = currMV->x;
				start_y = currMV->y;
				if (bDirection & 3)	/*our candidate is left or right */
				{
					CHECK_MV8_CANDIDATE_DIR(start_x, start_y + iDiamondSize, 8);
					CHECK_MV8_CANDIDATE_DIR(start_x, start_y - iDiamondSize, 4);
				} else			/* what remains here is up or down */
				{
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize, start_y, 2);
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize, start_y, 1);
				}

				if (iDirection) {
					bDirection += iDirection;
					start_x = currMV->x;
					start_y = currMV->y;
				}
			} else				/*about to quit, eh? not so fast.... */
			{
				switch (bDirection) {
				case 2:
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y - iDiamondSize, 2 + 4);
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y + iDiamondSize, 2 + 8);
					break;
				case 1:
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y - iDiamondSize, 1 + 4);
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y + iDiamondSize, 1 + 8);
					break;
				case 2 + 4:
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y - iDiamondSize, 1 + 4);
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y - iDiamondSize, 2 + 4);
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y + iDiamondSize, 2 + 8);
					break;
				case 4:
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y - iDiamondSize, 2 + 4);
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y - iDiamondSize, 1 + 4);
					break;
				case 8:
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y + iDiamondSize, 2 + 8);
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y + iDiamondSize, 1 + 8);
					break;
				case 1 + 4:
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y + iDiamondSize, 1 + 8);
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y - iDiamondSize, 1 + 4);
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y - iDiamondSize, 2 + 4);
					break;
				case 2 + 8:
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y - iDiamondSize, 1 + 4);
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y + iDiamondSize, 1 + 8);
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y + iDiamondSize, 2 + 8);
					break;
				case 1 + 8:
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y - iDiamondSize, 2 + 4);
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y + iDiamondSize, 2 + 8);
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y + iDiamondSize, 1 + 8);
					break;
				default:		/*1+2+4+8 == we didn't find anything at all */
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y - iDiamondSize, 1 + 4);
					CHECK_MV8_CANDIDATE_DIR(start_x - iDiamondSize,
											start_y + iDiamondSize, 1 + 8);
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y - iDiamondSize, 2 + 4);
					CHECK_MV8_CANDIDATE_DIR(start_x + iDiamondSize,
											start_y + iDiamondSize, 2 + 8);
					break;
				}
				if (!(iDirection))
					break;		/*ok, the end. really */
				else {
					bDirection = iDirection;
					start_x = currMV->x;
					start_y = currMV->y;
				}
			}
		}
		while (1);				/*forever */
	}
	return iMinSAD;
}


int32_t
Full8_MainSearch(const uint8_t * const pRef,
				 const uint8_t * const pRefH,
				 const uint8_t * const pRefV,
				 const uint8_t * const pRefHV,
				 const uint8_t * const cur,
				 const int x,
				 const int y,
			   const int start_x,
			   const int start_y,
			   int iMinSAD,
			   VECTOR * const currMV,
			   const int center_x,
			   const int center_y,
				 const int32_t min_dx,
				 const int32_t max_dx,
				 const int32_t min_dy,
				 const int32_t max_dy,
				 const int32_t iEdgedWidth,
				 const int32_t iDiamondSize,
				 const int32_t iFcode,
				 const int32_t iQuant,
				 int iFound)
{
	int32_t iSAD;
	int32_t dx, dy;
	VECTOR backupMV;

	backupMV.x = start_x;
	backupMV.y = start_y;

	for (dx = min_dx; dx <= max_dx; dx += iDiamondSize)
		for (dy = min_dy; dy <= max_dy; dy += iDiamondSize)
			NOCHECK_MV8_CANDIDATE(dx, dy);

	return iMinSAD;
}

Halfpel8_RefineFuncPtr Halfpel8_Refine;

int32_t
Halfpel16_Refine(const uint8_t * const pRef,
				 const uint8_t * const pRefH,
				 const uint8_t * const pRefV,
				 const uint8_t * const pRefHV,
				 const uint8_t * const cur,
				 const int x,
				 const int y,
				 VECTOR * const currMV,
				 int32_t iMinSAD,
			   const int center_x,
			   const int center_y,
				 const int32_t min_dx,
				 const int32_t max_dx,
				 const int32_t min_dy,
				 const int32_t max_dy,
				 const int32_t iFcode,
				 const int32_t iQuant,
				 const int32_t iEdgedWidth)
{
/* Do a half-pel refinement (or rather a "smallest possible amount" refinement) */

	int32_t iSAD;
	VECTOR backupMV = *currMV;

	CHECK_MV16_CANDIDATE(backupMV.x - 1, backupMV.y - 1);
	CHECK_MV16_CANDIDATE(backupMV.x, backupMV.y - 1);
	CHECK_MV16_CANDIDATE(backupMV.x + 1, backupMV.y - 1);
	CHECK_MV16_CANDIDATE(backupMV.x - 1, backupMV.y);
	CHECK_MV16_CANDIDATE(backupMV.x + 1, backupMV.y);
	CHECK_MV16_CANDIDATE(backupMV.x - 1, backupMV.y + 1);
	CHECK_MV16_CANDIDATE(backupMV.x, backupMV.y + 1);
	CHECK_MV16_CANDIDATE(backupMV.x + 1, backupMV.y + 1);

	return iMinSAD;
}

#define PMV_HALFPEL16 (PMV_HALFPELDIAMOND16|PMV_HALFPELREFINE16)



int32_t
PMVfastSearch16(const uint8_t * const pRef,
				const uint8_t * const pRefH,
				const uint8_t * const pRefV,
				const uint8_t * const pRefHV,
				const IMAGE * const pCur,
				const int x,
				const int y,
				const int start_x,	/* start is searched first, so it should contain the most */
				const int start_y,  /* likely motion vector for this block */
				const int center_x,	/* center is from where length of MVs is measured */
				const int center_y,
				const uint32_t MotionFlags,
				const uint32_t iQuant,
				const uint32_t iFcode,
				const MBParam * const pParam,
				const MACROBLOCK * const pMBs,
				const MACROBLOCK * const prevMBs,
				VECTOR * const currMV,
				VECTOR * const currPMV)
{
	const uint32_t iWcount = pParam->mb_width;
	const int32_t iWidth = pParam->width;
	const int32_t iHeight = pParam->height;
	const int32_t iEdgedWidth = pParam->edged_width;

	const uint8_t *cur = pCur->y + x * 16 + y * 16 * iEdgedWidth;

	int32_t iDiamondSize;

	int32_t min_dx;
	int32_t max_dx;
	int32_t min_dy;
	int32_t max_dy;

	int32_t iFound;

	VECTOR newMV;
	VECTOR backupMV;			/* just for PMVFAST */

	VECTOR pmv[4];
	int32_t psad[4];

	MainSearch16FuncPtr MainSearchPtr;

	const MACROBLOCK *const prevMB = prevMBs + x + y * iWcount;

	int32_t threshA, threshB;
	int32_t bPredEq;
	int32_t iMinSAD, iSAD;

/* Get maximum range */
	get_range(&min_dx, &max_dx, &min_dy, &max_dy, x, y, 16, iWidth, iHeight,
			  iFcode);

/* we work with abs. MVs, not relative to prediction, so get_range is called relative to 0,0 */

	if (!(MotionFlags & PMV_HALFPEL16)) {
		min_dx = EVEN(min_dx);
		max_dx = EVEN(max_dx);
		min_dy = EVEN(min_dy);
		max_dy = EVEN(max_dy);
	}

	/* because we might use something like IF (dx>max_dx) THEN dx=max_dx; */
	bPredEq = get_pmvdata2(pMBs, iWcount, 0, x, y, 0, pmv, psad);

	if ((x == 0) && (y == 0)) {
		threshA = 512;
		threshB = 1024;
	} else {
		threshA = psad[0];
		threshB = threshA + 256;
		if (threshA < 512)
			threshA = 512;
		if (threshA > 1024)
			threshA = 1024;
		if (threshB > 1792)
			threshB = 1792;
	}

	iFound = 0;

/* Step 4: Calculate SAD around the Median prediction. 
   MinSAD=SAD 
   If Motion Vector equal to Previous frame motion vector 
   and MinSAD<PrevFrmSAD goto Step 10. 
   If SAD<=256 goto Step 10. 
*/

	currMV->x = start_x;		
	currMV->y = start_y;		

	if (!(MotionFlags & PMV_HALFPEL16)) {	/* This should NOT be necessary! */
		currMV->x = EVEN(currMV->x);
		currMV->y = EVEN(currMV->y);
	}

	if (currMV->x > max_dx) {
		currMV->x = max_dx;
	}
	if (currMV->x < min_dx) {
		currMV->x = min_dx;
	}
	if (currMV->y > max_dy) {
		currMV->y = max_dy;
	}
	if (currMV->y < min_dy) {
		currMV->y = min_dy;
	}

	iMinSAD =
		sad16(cur,
			  get_ref_mv(pRef, pRefH, pRefV, pRefHV, x, y, 16, currMV,
						 iEdgedWidth), iEdgedWidth, MV_MAX_ERROR);
	iMinSAD +=
		calc_delta_16(currMV->x - center_x, currMV->y - center_y,
					  (uint8_t) iFcode, iQuant);

	if ((iMinSAD < 256) ||
		((MVequal(*currMV, prevMB->mvs[0])) &&
		 ((int32_t) iMinSAD < prevMB->sad16))) {
		if (iMinSAD < (int)(2 * iQuant))	/* high chances for SKIP-mode */
		{
			if (!MVzero(*currMV)) {
				iMinSAD += MV16_00_BIAS;
				CHECK_MV16_ZERO;	/* (0,0) saves space for letterboxed pictures */
				iMinSAD -= MV16_00_BIAS;
			}
		}

		if (MotionFlags & PMV_QUICKSTOP16)
			goto PMVfast16_Terminate_without_Refine;
		if (MotionFlags & PMV_EARLYSTOP16)
			goto PMVfast16_Terminate_with_Refine;
	}


/* Step 2 (lazy eval): Calculate Distance= |MedianMVX| + |MedianMVY| where MedianMV is the motion 
   vector of the median. 
   If PredEq=1 and MVpredicted = Previous Frame MV, set Found=2  
*/

	if ((bPredEq) && (MVequal(pmv[0], prevMB->mvs[0])))
		iFound = 2;

/* Step 3 (lazy eval): If Distance>0 or thresb<1536 or PredEq=1 Select small Diamond Search. 
   Otherwise select large Diamond Search. 
*/

	if ((!MVzero(pmv[0])) || (threshB < 1536) || (bPredEq))
		iDiamondSize = 1;		/* halfpel! */
	else
		iDiamondSize = 2;		/* halfpel! */

	if (!(MotionFlags & PMV_HALFPELDIAMOND16))
		iDiamondSize *= 2;

/* 
   Step 5: Calculate SAD for motion vectors taken from left block, top, top-right, and Previous frame block. 
   Also calculate (0,0) but do not subtract offset. 
   Let MinSAD be the smallest SAD up to this point. 
   If MV is (0,0) subtract offset. 
*/

/* (0,0) is always possible */

	if (!MVzero(pmv[0]))
		CHECK_MV16_ZERO;

/* previous frame MV is always possible */

	if (!MVzero(prevMB->mvs[0]))
		if (!MVequal(prevMB->mvs[0], pmv[0]))
			CHECK_MV16_CANDIDATE(prevMB->mvs[0].x, prevMB->mvs[0].y);

/* left neighbour, if allowed */

	if (!MVzero(pmv[1]))
		if (!MVequal(pmv[1], prevMB->mvs[0]))
			if (!MVequal(pmv[1], pmv[0])) {
				if (!(MotionFlags & PMV_HALFPEL16)) {
					pmv[1].x = EVEN(pmv[1].x);
					pmv[1].y = EVEN(pmv[1].y);
				}

				CHECK_MV16_CANDIDATE(pmv[1].x, pmv[1].y);
			}
/* top neighbour, if allowed */
	if (!MVzero(pmv[2]))
		if (!MVequal(pmv[2], prevMB->mvs[0]))
			if (!MVequal(pmv[2], pmv[0]))
				if (!MVequal(pmv[2], pmv[1])) {
					if (!(MotionFlags & PMV_HALFPEL16)) {
						pmv[2].x = EVEN(pmv[2].x);
						pmv[2].y = EVEN(pmv[2].y);