text_code.c

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	free(DC_store);

	free ((Char*)qcoeff);

}

/***********************************************************CommentBegin******
 *
 * -- Bits_CountMB_combined -- texture encoding for combined texture/motion
 *
 * Purpose :
 *	Used for texture encoding in case of combined texture/motion
 * 		encoding. This function encodes the :
 *		- COD flag
 *		- MCBPC flag
 *		- CBPY flag
 *		- CBPC flag
 *		- DQUANT information
 *
 * Arguments in :
 *	SInt Mode : The macroblock encoding mode
 * 	Int CBP : Coded block pattern information
 * 	Int COD : Indicates whether this macroblock is coded or not
 *	Int ACpred_flag
 * 	Int vop_type : indicates the picture coding type
 *		(Intra,Inter)
 *
 * Arguments out :
 *	Bits* bits : a structure counting the number of bits
 * 	Image *bitstream : output texture bit stream *
 *
 ***********************************************************CommentEnd********/

Void Bits_CountMB_combined(Int DQUANT, Int Mode, Int COD, Int ACpred_flag,
Int CBP, Int vop_type,
Bits* bits, Image *mottext_bitstream,Int *MB_transp_pattern)
{
	Int   cbpy ,cbpc, length;
	Int   MBtype=-1;

	if ( Mode == MODE_INTRA ) MBtype = 3;
	if ( Mode == MODE_INTER ) MBtype = 0;
	if ( Mode == MODE_INTRA_Q) MBtype = 4;
	if ( Mode == MODE_INTER_Q) MBtype = 1;
	if ( Mode == MODE_INTER4V) MBtype = 2;

	/* modified by NTT for GMC coding : start
	  if ( Mode == MODE_DYN_SP) MBtype = 0;
	  if ( Mode == MODE_DYN_SP_Q) MBtype = 1;
	*/
	if ( Mode == MODE_GMC) MBtype = 0;
	if ( Mode == MODE_GMC_Q) MBtype = 1;
	/* modified by NTT for GMC coding : end */

	#ifdef D_TRACE
	fprintf(ftrace, "DQUANT : %d\tMODE : %d\tVop Type : %d\n", DQUANT, Mode, vop_type);
	fprintf(ftrace, "COD : %d\tCBP : %d\tAC Pred Flag : %d\n\n", COD, CBP, ACpred_flag);
	#endif

	cbpc = CBP & 3;
	cbpy = CBP>>2;

	/* COD */

	if (vop_type != PCT_INTRA )
	{
		if (COD)
		{
			printf("COD = 1 in Bits_CountMB_combined \n");
			printf("This function should not be used if COD is '1' \n");
			exit(1);
		}

												  /* write COD */
		BitstreamPutBits(mottext_bitstream, (long)(COD), 1L);
		bits->COD++;
	}

	/* MCBPC */

	if (vop_type == PCT_INTRA)
		length = PutMCBPC_Intra (cbpc, MBtype, mottext_bitstream);
	else
		length = PutMCBPC_Inter (cbpc, MBtype, mottext_bitstream);

	bits->MCBPC += length;

	/* MCSEL syntax */
	/* modified by NTT for GMC coding : start
	 if (((Mode == MODE_INTER) || (Mode == MODE_INTER_Q) || (Mode == MODE_DYN_SP) || (Mode == MODE_DYN_SP_Q))  && (vop_type == PCT_SPRITE))
	*/
	if (((Mode == MODE_INTER) || (Mode == MODE_INTER_Q) || (Mode == MODE_GMC) || (Mode == MODE_GMC_Q))  && (vop_type == PCT_SPRITE))
		/* modified by NTT for GMC coding : end */
	{
		if ((Mode == MODE_INTER) || (Mode == MODE_INTER_Q))
			BitstreamPutBits(mottext_bitstream, (long) 0, 1L);
		/* modified by NTT for GMC coding : start
			  if ((Mode == MODE_DYN_SP) || (Mode == MODE_DYN_SP_Q))
		*/
		if ((Mode == MODE_GMC) || (Mode == MODE_GMC_Q))
			/* modified by NTT for GMC coding : end */
			BitstreamPutBits(mottext_bitstream, (long) 1, 1L);

		bits->MCBPC += 1;
	}

	/* ACpred_flag */
	/* 17-Jan-97 JDL : correction no ACpred_flag in combined mode when intra_acdc_pred_disable is true */
	if ((Mode == MODE_INTRA || Mode==MODE_INTRA_Q) && ACpred_flag != -1)
	{
		BitstreamPutBits(mottext_bitstream, (long)ACpred_flag, 1L);
		bits->ACpred_flag += 1;
	}

	/* CBPY */

	length = PutCBPY (cbpy, (Char)(Mode==MODE_INTRA||Mode==MODE_INTRA_Q),/*MB_transp_pattern*/NULL,mottext_bitstream);

	bits->CBPY += length;

	/* DQUANT */

	/* modified by NTT for GMC coding : start
	  if ((Mode == MODE_INTER_Q) || (Mode == MODE_INTRA_Q)|| (Mode == MODE_DYN_SP_Q))
	*/
	if ((Mode == MODE_INTER_Q) || (Mode == MODE_INTRA_Q)|| (Mode == MODE_GMC_Q))
		/* modified by NTT for GMC coding : end */
	{
		switch (DQUANT)
		{
			case -1:
				BitstreamPutBits(mottext_bitstream, 0L, 2L);
				break;
			case -2:
				BitstreamPutBits(mottext_bitstream, 1L, 2L);
				break;
			case 1:
				BitstreamPutBits(mottext_bitstream, 2L, 2L);
				break;
			case 2:
				BitstreamPutBits(mottext_bitstream, 3L, 2L);
				break;
			default:
				fprintf(stderr,"Invalid DQUANT\n");
				exit(1);
		}
		bits->DQUANT += 2;
	}
}


/***********************************************************CommentBegin******
 *
 * -- doDCACpred -- Does DC/AC prediction. Changes qcoeff values as
 *		    appropriate.
 *
 * Purpose :
 *	Does DC/AC prediction. Changes qcoeff values as appropriate.
 *
 * Arguments in :
 *	Int CBP
 *	Int ncoeffs
 *	Int x_pos
 *	Int y_pos
 *	Int DC_store[][6][15]  	Stores coefficient values per MB for
 *			       	prediction (for one Vop)
 *	Int QP			QP value for this MB
 *	Int MB_width
 *
 * Arguments in/out :
 *	Int *qcoeff
 *
 * Return values :
 *	Int	The ACpred_flag, which is to be put into the bitstream
 *
 * Side effects :
 *	Modifies qcoeff if needed for the prediction.
 *
 ***********************************************************CommentEnd********/

Int doDCACpred(Int *qcoeff, Int *CBP, Int ncoeffs, Int x_pos, Int y_pos,
Int ***DC_store, Int QP, Int MB_width,
Int direction[], Int mid_grey )
{
	Int i, m;
	Int block_A, block_B, block_C;
	Int Xpos[6] = {-1, 0, -1, 0, -1, -1};
	Int Ypos[6] = {-1, -1, 0, 0, -1, -1};
	Int Xtab[6] = {1, 0, 3, 2, 4, 5};
	Int Ytab[6] = {2, 3, 0, 1, 4, 5};
	Int Ztab[6] = {3, 2, 1, 0, 4, 5};
	Int grad_hor, grad_ver, DC_pred;
	Int pred_A[15], pred_C[15];
	Int S = 0, S1, S2;
	Int diff;
	Int pcoeff[384];
	Int ACpred_flag=-1;

	/* Copy qcoeff to the prediction array pcoeff */
	for (i = 0; i < (6*ncoeffs); i++)
	{
		pcoeff[i] = qcoeff[i];
	}

	for (i = 0; i < 6; i++)
	{
		if ((x_pos == 0) && y_pos == 0)			  /* top left corner */
		{
			block_A = (i == 1 || i == 3) ? DC_store[y_pos*MB_width+(x_pos+Xpos[i])][Xtab[i]][0] : mid_grey*8;
			block_B = (i == 3) ? DC_store[(y_pos+Ypos[i])*MB_width+(x_pos+Xpos[i])][Ztab[i]][0] : mid_grey*8;
			block_C = (i == 2 || i == 3) ? DC_store[(y_pos+Ypos[i])*MB_width+x_pos][Ytab[i]][0] : mid_grey*8;
		}
		else if (x_pos == 0)					  /* left edge */
		{
			block_A = (i == 1 || i == 3) ? DC_store[y_pos*MB_width+(x_pos+Xpos[i])][Xtab[i]][0] : mid_grey*8;
			block_B = (i == 1 || i == 3) ? DC_store[(y_pos+Ypos[i])*MB_width+(x_pos+Xpos[i])][Ztab[i]][0] : mid_grey*8;
			block_C = DC_store[(y_pos+Ypos[i])*MB_width+x_pos][Ytab[i]][0];
		}
		else if (y_pos == 0)					  /* top row */
		{
			block_A = DC_store[y_pos*MB_width+(x_pos+Xpos[i])][Xtab[i]][0];
			block_B = (i == 2 || i == 3) ? DC_store[(y_pos+Ypos[i])*MB_width+(x_pos+Xpos[i])][Ztab[i]][0] : mid_grey*8;
			block_C = (i == 2 || i == 3) ? DC_store[(y_pos+Ypos[i])*MB_width+x_pos][Ytab[i]][0] : mid_grey*8;
		}
		else
		{
			block_A = DC_store[y_pos*MB_width+(x_pos+Xpos[i])][Xtab[i]][0];
			block_B = (DC_store[(y_pos+Ypos[i])*MB_width+(x_pos+Xpos[i])]
				[Ztab[i]][0]);
			block_C = DC_store[(y_pos+Ypos[i])*MB_width+x_pos][Ytab[i]][0];
		}
		grad_hor = block_B - block_C;
		grad_ver = block_A - block_B;

		if ((ABS(grad_ver)) < (ABS(grad_hor)))
		{
			DC_pred = block_C;
			direction[i] = 2;
		}
		else
		{
			DC_pred = block_A;
			direction[i] = 1;
		}

		pcoeff[i*ncoeffs] = qcoeff[i*ncoeffs] - (DC_pred+cal_dc_scaler(QP,(i<4)?1:2)/2)/cal_dc_scaler(QP,(i<4)?1:2);

		/* Find AC predictions */
		if ((x_pos == 0) && y_pos == 0)			  /* top left corner */
		{
			if (i == 1 || i == 3)
				for (m = 0; m < 15; m++)
					pred_A[m] = Idir_c(((DC_store[y_pos*MB_width+(x_pos+Xpos[i])][Xtab[i]][m]) * QP*2) , 2*QP);
			else
				nullfill(pred_A,mid_grey);
			if (i == 2 || i == 3)
				for (m = 0; m < 15; m++)
					pred_C[m] = Idir_c(((DC_store[(y_pos+Ypos[i])*MB_width+x_pos][Ytab[i]][m]) * QP*2) , 2*QP);
			else
				nullfill(pred_C,mid_grey);
		}
		else if (x_pos == 0)					  /* left edge */
		{
			if (i == 1 || i == 3)
				for (m = 0; m < 15; m++)
					pred_A[m] = Idir_c(((DC_store[y_pos*MB_width+(x_pos+Xpos[i])][Xtab[i]][m]) * QP*2) , 2*QP);
			else
				nullfill(pred_A,mid_grey);
			for (m = 0; m < 15; m++)
				pred_C[m] = Idir_c(((DC_store[(y_pos+Ypos[i])*MB_width+x_pos][Ytab[i]][m]) * QP*2) , 2*QP);
		}
		else if (y_pos == 0)					  /* top row */
		{
			for (m = 0; m < 15; m++)
				pred_A[m] = Idir_c(((DC_store[y_pos*MB_width+(x_pos+Xpos[i])][Xtab[i]][m]) * QP*2) , 2*QP);
			if (i == 2 || i == 3)
				for (m = 0; m < 15; m++)
					pred_C[m] = Idir_c(((DC_store[(y_pos+Ypos[i])*MB_width+x_pos][Ytab[i]][m]) * QP*2) , 2*QP);
			else
				nullfill(pred_C,mid_grey);
		}
		else
		{
			for (m = 0; m < 15; m++)
			{
				pred_A[m] = Idir_c(((DC_store[y_pos*MB_width+(x_pos+Xpos[i])][Xtab[i]][m]) * QP*2) , 2*QP);
				pred_C[m] = Idir_c(((DC_store[(y_pos+Ypos[i])*MB_width+x_pos][Ytab[i]][m]) * QP*2) , 2*QP);
			}
		}

		#if 1									  /* I think it should be like this, 14-NOV-1996 MW */
		S1 = 0;
		S2 = 0;
		/* Now decide on AC prediction */
		if (direction[i] == 1)					  /* Horizontal, left COLUMN of block A */
		{
			for (m = 0; m < 7; m++)
			{
				S1 += ABS(qcoeff[i*ncoeffs+(m+1)*8]);
				diff = pcoeff[i*ncoeffs+(m+1)*8]
					= qcoeff[i*ncoeffs+(m+1)*8] - pred_A[m+8];
				S2 += ABS(diff);
			}
		}
		else									  /* Vertical, top ROW of block C */
		{
			for (m = 1; m < 8; m++)
			{
				S1 += ABS(qcoeff[i*ncoeffs+m]);
				diff = pcoeff[i*ncoeffs+m]
					= qcoeff[i*ncoeffs+m] - pred_C[m];
				S2 += ABS(diff);
			}
		}
		S += (S1 - S2);
		#endif
	}
	/* Now change qcoeff for DC pred or DC/AC pred */
	if (S >=0)
	{
		for (i=0;i<ncoeffs*6; i++)
			/* Modified due to N2171 Cl. 2.2.14 MW 25-MAR-1998 */
			/* if ((i%64)&&(abs(pcoeff[i])>127)) { */
			if ((i%64)&&(abs(pcoeff[i])>2047))
		{
			printf("predicted AC out of range");
			S=-1;break;
		}
	}
	if (S >= 0)									  /* Both DC and AC prediction */
	{
		ACpred_flag = 1;
		for (i = 0; i < ncoeffs*6; i++)
		{
			qcoeff[i] = pcoeff[i];
		}
		/* Update CBP for predicted coeffs. */
		*CBP = FindCBP(qcoeff, MODE_INTRA, 64);
	}
	else										  /* Only DC prediction */
	{
		ACpred_flag = 0;
		for (i = 0; i < 6; i++)
		{
			qcoeff[i*ncoeffs] = pcoeff[i*ncoeffs];
			direction[i] = 0;
		}
	}
	return ACpred_flag;							  /* To be put into bitstream */
}

/**
 * Small routine to fill default prediction values into a DC_store entry
 */

Void nullfill(Int pred[], Int mid_grey)
{
	Int i;

	pred[0] = mid_grey*8;
	for (i = 1; i < 15; i++)
	{
		pred[i] = 0;
	}
}

Int Idir_c(Int val, Int QP)
{
	if (val<0) return (val-QP/2)/QP;
	else return (val+QP/2)/QP;
}


/***********************************************************CommentBegin******
 *
 * -- IntraDCSwitch_decisions --
 *
 * Purpose :
 *	decide whether to use inter AC table to encode DC
 *
 * Arguments in :
 *	Int Mode
 * 	Int intra_dc_vlc_thr
 * 	Int Qp
 *
 ***********************************************************CommentEnd********/

Int IntraDCSwitch_Decision(Int Mode,Int intra_dc_vlc_thr,Int Qp)
{
	Int switched =0;
	if (Mode == MODE_INTRA || Mode == MODE_INTRA_Q)
	{
		if (intra_dc_vlc_thr==0)
			switched=0;
		else if (intra_dc_vlc_thr==7)
			switched=1;
		else if (Qp>=intra_dc_vlc_thr*2+11)
			switched=1;
	}

	return switched;
}


/***********************************************************CommentBegin******
 *
 * -- cal_dc_scaler -- calculation of DC quantization scale according
 *					  to the incoming Q and type;
 *
 * Arguments in :
 *   Int Qp
 *
 ***********************************************************CommentEnd********/

Int cal_dc_scaler (Int QP, Int type)
{

	Int dc_scaler;
	if (type == 1)
	{
		if (QP > 0 && QP < 5) dc_scaler = 8;
		else if (QP > 4 && QP < 9) dc_scaler = 2 * QP;
		else if (QP > 8 && QP < 25) dc_scaler = QP + 8;
		else dc_scaler = 2 * QP - 16;
	}
	else
	{
		if (QP > 0 && QP < 5) dc_scaler = 8;
		else if (QP > 4 && QP < 25) dc_scaler = (QP + 13) / 2;
		else dc_scaler = QP - 6;
	}
	return dc_scaler;
}



/***********************************************************CommentBegin******
 *
 * -- FindCBP -- Find the CBP for a macroblock
 *
 * Purpose :
 * Find the CBP for a macroblock
 *
 * Arguments in :
 * Int *qcoeff : pointer to quantized coefficients
 *  Int Mode : macroblock encoding mode information
 *  Int ncoeffs : the number of coefficients
 *
 * Return values :
 * Int CBP : The coded block pattern for a macroblock
 *
 ***********************************************************CommentEnd********/

Int
FindCBP (Int* qcoeff, Int Mode, Int ncoeffs)
{
	Int i,j;
	Int CBP = 0;
	Int intra = (Mode == MODE_INTRA || Mode == MODE_INTRA_Q);

	/* Set CBP for this Macroblock */

	for (i = 0; i < 6; i++)
	{
		for (j = i*ncoeffs + intra; j < (i+1)*ncoeffs; j++)
		{

			if (qcoeff[j])
			{
				if (i == 0) {CBP |= 32;}
				else if (i == 1) {CBP |= 16;}
				else if (i == 2) {CBP |= 8;}
				else if (i == 3) {CBP |= 4;}
				else if (i == 4) {CBP |= 2;}
				else if (i == 5) {CBP |= 1;}
				else
				{
					fprintf (stderr, "Error in CBP assignment\n");
					exit(-1);
				}

				break;
			}
		}
	}

	return CBP;
}