mbtransquant.c

用MPEG-4对YUV视频文件编码压缩成divx视频文件

 /******************************************************************************
  *                                                                            *
  *  This file is part of XviD, a free MPEG-4 video encoder/decoder            *
  *                                                                            *
  *  XviD is an implementation of a part of one or more MPEG-4 Video tools     *
  *  as specified in ISO/IEC 14496-2 standard.  Those intending to use this    *
  *  software module in hardware or software products are advised that its     *
  *  use may infringe existing patents or copyrights, and any such use         *
  *  would be at such party's own risk.  The original developer of this        *
  *  software module and his/her company, and subsequent editors and their     *
  *  companies, will have no liability for use of this software or             *
  *  modifications or derivatives thereof.                                     *
  *                                                                            *
  *  XviD 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.                                       *
  *                                                                            *
  *  XviD 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  *
  *                                                                            *
  ******************************************************************************/

 /******************************************************************************
  *                                                                            *
  *  mbtransquant.c                                                            *
  *                                                                            *
  *  Copyright (C) 2001 - Peter Ross <[e-mail]>                    *
  *  Copyright (C) 2001 - Michael Militzer <[e-mail]>                  *
  *                                                                            *
  *  For more information visit the XviD homepage: http://www.xvid.org         *
  *                                                                            *
  ******************************************************************************/

 /******************************************************************************
  *                                                                            *
  *  Revision history:                                                         *
  *                                                                            *
  *  29.03.2002 interlacing speedup - used transfer strides instead of
  *             manual field-to-frame conversion
  *  26.03.2002 interlacing support - moved transfers outside loops
  *  22.12.2001 get_dc_scaler() moved to common.h
  *  19.11.2001 introduced coefficient thresholding (Isibaar)                  *
  *  17.11.2001 initial version                                                *
  *                                                                            *
  ******************************************************************************/

#include <string.h>

#include "../user_macro.h"
#include "../portab.h"
#include "mbfunctions.h"

#include "../global.h"
#include "mem_transfer.h"
#include "timer.h"
#include "../dct/fdct.h"
#include "../dct/idct.h"
#include "../quant/quant_mpeg4.h"
/*#include "../quant/quant_h263.h"*/
#include "../encoder.h"
/* whq,2002.12.19 */
/*#include "../prediction/mbprediction.h"*/
#include "../bitstream/cbp.h"


/*!
 ****************************************************************************
 * 
 * Add prediction in MBTransQuantIntra, 2002.12.22, by whq
 *
 ***************************************************************************
*/
#define TOOSMALL_LIMIT 1		/* skip blocks having a coefficient sum below this value */
/* whq,2002.12.19 prediction */
/*whq,2002.12.18*/
extern int16_t dc_quant[2][31];

/**************************ADD by zjy***************************/
extern FILE *ftestlog;
/***************************************************************/




/*whq,2002.12.18*/
static const int16_t default_acdc_values[15] = {
	1024,
	0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0
};


/*!
 ****************************************************************************
 * \brief
 *
 * predict ac,dc direction according to the neighbour blocks
 *
 ***************************************************************************
*/
void
predict_acdc(MACROBLOCK * pMBs,				/*<-- macroblock struct */		
			 uint32_t x,					/*<-- macroblock row pos */
			 uint32_t y,					/*<-- macroblock column pos */
			 uint32_t mb_width,				/*<-- macroblock number in a row */
			 uint32_t block,				/*<-- block number in a macroblock */
			 int16_t qcoeff[64],			/*<-- quant orig value,no use now*/
			 uint32_t current_quant,		/*<-- quant value */
			 uint32_t chrom_lumflag,		/*<-- chrom or lum block */
			 int16_t predictors[8])			/*<--> first row or column predict value */

{
/* whq,2002.12.17 ,delete */
/*
	const int mbpos = (y * mb_width) + x;
*/
	/*宏块的左、上、对角宏块的预测值*/
	int16_t *left, *top, *diag, *current;


/* whq,2002.12.17 */
/* save the first col and first row predict value */

	/*块的左、上、对角块的预测值*/
	const int16_t *pLeft = default_acdc_values;
	const int16_t *pTop = default_acdc_values;
	const int16_t *pDiag = default_acdc_values;
	int32_t level0,sign0;

	uint32_t index = x + y * mb_width;	/*current macroblock*/
	int *acpred_direction = &pMBs[index].acpred_directions[block];
	uint32_t i;

/*whq,2002.12.18*/
		
	
	int16_t (*q)[31];
	q = dc_quant;
	left = top = diag = current = 0;
/* use x,y to judge the macroblocks position */
	/* grab left,top and diag macroblocks*/
	/* 当前宏块的左边、上边，对角线宏块 */

	/* left macroblock*/ 

	if (x &&  
		(pMBs[index - 1].mode == MODE_INTRA ||
		 pMBs[index - 1].mode == MODE_INTRA_Q))
	{

		left = pMBs[index - 1].pred_values[0];

	}
	/* top macroblock*/

	if (y&&(pMBs[index - mb_width].mode == MODE_INTRA ||
		 pMBs[index - mb_width].mode == MODE_INTRA_Q)) {

		top = pMBs[index - mb_width].pred_values[0];

	}
	/* diag macroblock */

	if (x && y &&
		(pMBs[index - 1 - mb_width].mode == MODE_INTRA ||
		 pMBs[index - 1 - mb_width].mode == MODE_INTRA_Q)) {

		diag = pMBs[index - 1 - mb_width].pred_values[0];
	}

	current = pMBs[index].pred_values[0];

	/* now grab pLeft, pTop, pDiag _blocks_,for block level only  */
    /* 判断当前块所使用左边块，上边块和对角线块 */
	switch (block) {

	case 0:
		if (left)
			pLeft = left + MBPRED_SIZE;

		if (top)
			pTop = top + (MBPRED_SIZE << 1);

		if (diag)
			pDiag = diag + 3 * MBPRED_SIZE;

		break;

	case 1:
		pLeft = current;
/* whq,2002.12.17 ,delete */
/*
		left_quant = current_quant;
*/

		if (top) {
			pTop = top + 3 * MBPRED_SIZE;
			pDiag = top + (MBPRED_SIZE << 1);
		}
		break;

	case 2:
		if (left) {
			pLeft = left + 3 * MBPRED_SIZE;
			pDiag = left + MBPRED_SIZE;
		}

		pTop = current;
/* whq,2002.12.17 ,delete */
/*
		top_quant = current_quant;
*/

		break;

	case 3:
		pLeft = current + (MBPRED_SIZE << 1);
/* whq,2002.12.17 ,delete */
/*
		left_quant = current_quant;
		top_quant = current_quant;
*/

		pTop = current + MBPRED_SIZE;		
		pDiag = current;

		break;

	case 4:
		if (left)
			pLeft = left + (MBPRED_SIZE << 2);
		if (top)
			pTop = top + (MBPRED_SIZE << 2);
		if (diag)
			pDiag = diag + (MBPRED_SIZE << 2);
		break;

	case 5:
		if (left)
			pLeft = left + 5 * MBPRED_SIZE;
		if (top)
			pTop = top + 5 * MBPRED_SIZE;
		if (diag)
			pDiag = diag + 5 * MBPRED_SIZE;
		break;
	}

	/*  determine ac prediction direction & ac/dc predictor*/
	/*  place rescaled ac/dc predictions into predictors[] for later use*/
	/*  根据水平和垂直梯度判断预测值,pTop等中dc保存的是原始值，未经量化，
		ac保存的是经过量化的，predictor中保存的是量化后的还是？？？？？*/
	if (abs(pLeft[0] - pDiag[0]) < abs(pDiag[0] - pTop[0])) {
		*acpred_direction = 1;	/* vertical*/
		/*whq,2002.12.17, ???????????????*/
		
        /* whq,2002.12.18,look up the table to convert div to mul */	
		/*predictors[0] = DIV_DIV(pTop[0], iDcScaler);*/
		sign0  = max(min(pTop[0],1),-1);
		level0 = abs(pTop[0]);
		predictors[0] =(level0*(*(*(q+chrom_lumflag)+current_quant-1))+32768)>>16;
		predictors[0] = sign0*predictors[0];
		
		
		/*predictors[0] = pTop[0];*/
		for (i = 1; i < 8; i++) {
		/* whq,2002.12.17 ,delete */
		/*
			predictors[i] = rescale(top_quant, current_quant, pTop[i]);
		*/
			predictors[i] = pTop[i];

		}
	} else {
		*acpred_direction = 2;	/* horizontal*/
		/*whq,2002.12.17, ???????????????*/
		
		/*predictors[0] = DIV_DIV(pLeft[0], iDcScaler);*/

		sign0  = max(min(pLeft[0],1),-1);
		level0 = abs(pLeft[0]);
		predictors[0] =(level0*(*(*(q+chrom_lumflag)+current_quant-1))+32768)>>16;
		predictors[0] = sign0*predictors[0];
		/*predictors[0] = pLeft[0];*/

		for (i = 1; i < 8; i++) {
		/* whq,2002.12.17 ,delete */
		/*
			predictors[i] = rescale(left_quant, current_quant, pLeft[i + 7]);
		*/
			predictors[i] =  pLeft[i + 7];

		}
	}
}


/*!
 ****************************************************************************
 * \brief
 *
 *		compute the diff between sum of abs(level) and sum of 
 *      abs(predict-diff) for deciding predict or not
 *      
 ***************************************************************************
*/
int32_t							/*==> return the diff to judge use prediction or not*/
calc_acdc(MACROBLOCK * pMB,			/*<-- macroblock struct */	
		  uint32_t block,			/*<-- block number in a macroblock */
		  int16_t qcoeff[64],		/*<--> in:quant orig value/out:dc diff,other not change*/
		  uint32_t iDcScaler,		/*<-- dc quant scaler */
		  int16_t predictors[8]		/*<--> in:predict row or column value
										  /out:dc not change,but ac is the diff*/
		  )
{
	int16_t *pCurrent = pMB->pred_values[block];
	uint32_t i;
	uint32_t S1 = 0, S2 = 0;
	int16_t level;


	/* store current coeffs to pred_values[] for future prediction */
	/* pCurrent[0]??,whq,2002.12.17 ，
	   qcoeff[0]的意义是dc经过量化的结果
		恢复成量化前的，用于以后块的dc预测*/

	
	pCurrent[0] = qcoeff[0] * iDcScaler;

	
	for (i = 1; i < 8; i++) {
		pCurrent[i] = qcoeff[i];
		pCurrent[i + 7] = qcoeff[i * 8];
	}

	/* subtract predictors and store back in predictors[] */
	/*whq,predictors ?? */
	/*qcoeff[0] = qcoeff[0] - predictors[0];*/
	/*dc must be predict,ac is not sure */
	/* whq,2002.12.18 */
	qcoeff[0] = qcoeff[0] - predictors[0];

	if (pMB->acpred_directions[block] == 1) {
		for (i = 1; i < 8; i++) {

			level = qcoeff[i];
			S2 += abs(level);
			level -= predictors[i];
			S1 += abs(level);
			predictors[i] = level;
		}
	} else						/*acpred_direction == 2*/
	{