estimation_common.c

xvid解码的精简版本.非常好的版本,节省了分离xvid源代码的过程

/*****************************************************************************
 *
 *  XVID MPEG-4 VIDEO CODEC
 *  - Motion Estimation shared functions -
 *
 *  Copyright(C) 2002 Christoph Lampert <[e-mail]>
 *               2002 Michael Militzer <[e-mail]>
 *               2002-2003 Radoslaw Czyz <[e-mail]>
 *
 *  This program is free software ; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation ; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY ; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program ; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 * $Id: estimation_common.c,v 1.12.2.1 2005/12/09 05:07:31 syskin Exp $
 *
 ****************************************************************************/

#include "encoder.h"
#include "global.h"
#include "interpolate8x8.h"
#include "estimation.h"
#include "motion.h"

#include "motion_inlines.h"


/*****************************************************************************
 * Modified rounding tables
 * Original tables see ISO spec tables 7-6 -> 7-9
 ****************************************************************************/

const uint32_t roundtab[16] =
{0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2 };

/* K = 4 */
const uint32_t roundtab_76[16] =
{ 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1 };

/* K = 2 */
const uint32_t roundtab_78[8] =
{ 0, 0, 1, 1, 0, 0, 0, 1  };

/* K = 1 */
const uint32_t roundtab_79[4] =
{ 0, 1, 0, 0 };


/*****************************************************************************
 * Code
 ****************************************************************************/


uint8_t *
xvid_me_interpolate8x8qpel(const int x, const int y, const uint32_t block, const uint32_t dir, const SearchData * const data)
{
	/* create or find a qpel-precision reference picture; return pointer to it */
	uint8_t * Reference = data->RefQ + 16*dir;
	const uint32_t iEdgedWidth = data->iEdgedWidth;
	const uint32_t rounding = data->rounding;
	const int halfpel_x = x/2;
	const int halfpel_y = y/2;
	const uint8_t *ref1, *ref2, *ref3, *ref4;

	ref1 = GetReferenceB(halfpel_x, halfpel_y, dir, data);
	ref1 += 8 * (block&1) + 8 * (block>>1) * iEdgedWidth;
	switch( ((x&1)<<1) + (y&1) ) {
	case 3: /* x and y in qpel resolution - the "corners" (top left/right and */
			/* bottom left/right) during qpel refinement */
		ref2 = GetReferenceB(halfpel_x, y - halfpel_y, dir, data);
		ref3 = GetReferenceB(x - halfpel_x, halfpel_y, dir, data);
		ref4 = GetReferenceB(x - halfpel_x, y - halfpel_y, dir, data);
		ref2 += 8 * (block&1) + 8 * (block>>1) * iEdgedWidth;
		ref3 += 8 * (block&1) + 8 * (block>>1) * iEdgedWidth;
		ref4 += 8 * (block&1) + 8 * (block>>1) * iEdgedWidth;
		interpolate8x8_avg4(Reference, ref1, ref2, ref3, ref4, iEdgedWidth, rounding);
		break;

	case 1: /* x halfpel, y qpel - top or bottom during qpel refinement */
		ref2 = GetReferenceB(halfpel_x, y - halfpel_y, dir, data);
		ref2 += 8 * (block&1) + 8 * (block>>1) * iEdgedWidth;
		interpolate8x8_avg2(Reference, ref1, ref2, iEdgedWidth, rounding, 8);
		break;

	case 2: /* x qpel, y halfpel - left or right during qpel refinement */
		ref2 = GetReferenceB(x - halfpel_x, halfpel_y, dir, data);
		ref2 += 8 * (block&1) + 8 * (block>>1) * iEdgedWidth;
		interpolate8x8_avg2(Reference, ref1, ref2, iEdgedWidth, rounding, 8);
		break;

	default: /* pure halfpel position */
		return (uint8_t *) ref1;

	}
	return Reference;
}

uint8_t *
xvid_me_interpolate16x16qpel(const int x, const int y, const uint32_t dir, const SearchData * const data)
{
	/* create or find a qpel-precision reference picture; return pointer to it */
	uint8_t * Reference = data->RefQ + 16*dir;
	const uint32_t iEdgedWidth = data->iEdgedWidth;
	const uint32_t rounding = data->rounding;
	const int halfpel_x = x/2;
	const int halfpel_y = y/2;
	const uint8_t *ref1, *ref2, *ref3, *ref4;

	ref1 = GetReferenceB(halfpel_x, halfpel_y, dir, data);
	switch( ((x&1)<<1) + (y&1) ) {
	case 3:
		/*
		 * x and y in qpel resolution - the "corners" (top left/right and
		 * bottom left/right) during qpel refinement
		 */
		ref2 = GetReferenceB(halfpel_x, y - halfpel_y, dir, data);
		ref3 = GetReferenceB(x - halfpel_x, halfpel_y, dir, data);
		ref4 = GetReferenceB(x - halfpel_x, y - halfpel_y, dir, data);
		interpolate8x8_avg4(Reference, ref1, ref2, ref3, ref4, iEdgedWidth, rounding);
		interpolate8x8_avg4(Reference+8, ref1+8, ref2+8, ref3+8, ref4+8, iEdgedWidth, rounding);
		interpolate8x8_avg4(Reference+8*iEdgedWidth, ref1+8*iEdgedWidth, ref2+8*iEdgedWidth, ref3+8*iEdgedWidth, ref4+8*iEdgedWidth, iEdgedWidth, rounding);
		interpolate8x8_avg4(Reference+8*iEdgedWidth+8, ref1+8*iEdgedWidth+8, ref2+8*iEdgedWidth+8, ref3+8*iEdgedWidth+8, ref4+8*iEdgedWidth+8, iEdgedWidth, rounding);
		break;

	case 1: /* x halfpel, y qpel - top or bottom during qpel refinement */
		ref2 = GetReferenceB(halfpel_x, y - halfpel_y, dir, data);
		interpolate8x8_avg2(Reference, ref1, ref2, iEdgedWidth, rounding, 8);
		interpolate8x8_avg2(Reference+8, ref1+8, ref2+8, iEdgedWidth, rounding, 8);
		interpolate8x8_avg2(Reference+8*iEdgedWidth, ref1+8*iEdgedWidth, ref2+8*iEdgedWidth, iEdgedWidth, rounding, 8);
		interpolate8x8_avg2(Reference+8*iEdgedWidth+8, ref1+8*iEdgedWidth+8, ref2+8*iEdgedWidth+8, iEdgedWidth, rounding, 8);
		break;

	case 2: /* x qpel, y halfpel - left or right during qpel refinement */
		ref2 = GetReferenceB(x - halfpel_x, halfpel_y, dir, data);
		interpolate8x8_avg2(Reference, ref1, ref2, iEdgedWidth, rounding, 8);
		interpolate8x8_avg2(Reference+8, ref1+8, ref2+8, iEdgedWidth, rounding, 8);
		interpolate8x8_avg2(Reference+8*iEdgedWidth, ref1+8*iEdgedWidth, ref2+8*iEdgedWidth, iEdgedWidth, rounding, 8);
		interpolate8x8_avg2(Reference+8*iEdgedWidth+8, ref1+8*iEdgedWidth+8, ref2+8*iEdgedWidth+8, iEdgedWidth, rounding, 8);
		break;


	default: /* pure halfpel position */
		return (uint8_t *) ref1;
	}
	return Reference;
}