www.pudn.com > mpeg4_DECORE.rar > deblock_vert_DC_on.c

/************************************************************************** 
 *                                                                        * 
 * This code has been developed by John Funnell. This software 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 (including Project Mayo), will have no liability for use of  * 
 * this software or modifications or derivatives thereof.                 * 
 *                                                                        * 
 * Project Mayo gives users of the Codec a license to this software       * 
 * module or modifications thereof for use in hardware or software        * 
 * products claiming conformance to the MPEG-4 Video Standard as          * 
 * described in the Open DivX license.                                    * 
 *                                                                        * 
 * The complete Open DivX license can be found at                         * 
 * http://www.projectmayo.com/opendivx/license.php                        * 
 *                                                                        * 
 **************************************************************************/ 
/** 
*  Copyright (C) 2001 - Project Mayo 
 * 
 * John Funnell 
 * 
 * DivX Advanced Research Center  
* 
**/ 
 
/*** 
 
References:   
 * ISO/IEC 14496-2 
 * MoMuSys-FDIS-V1.0-990812 
 * Intel Architecture Software Developer's Manual 
   Volume 2: Instruction Set Reference 
 
***/ 
 
#include "postprocess_mmx.h" 
 
 
/* John Funnell, December 2000 */ 
 
 
 
/* decide whether the DC filter should be turned on accoding to QP */ 
INLINE int deblock_vert_DC_on(uint8_t *v, int stride, int QP) { 
	uint64_t QP_x_2; 
	uint8_t *ptr1; 
	uint8_t *ptr2; 
	int DC_on; 
	#ifdef PP_SELF_CHECK 
	int i, DC_on2; 
	#endif 
 
	ptr1 = &(v[1*stride]); 
	ptr2 = &(v[8*stride]); 
 
	#ifdef PP_SELF_CHECK 
	DC_on2 = 1; 
	for (i=0; i<8; i++) { 
		if (ABS(v[i+1*stride]-v[i+8*stride]) > 2 *QP) DC_on2 = 0; 
	} 
	#endif 
 
	/* load 2*QP into every byte in QP_x_2 */ 
	((uint32_t *)(&QP_x_2))[0] = 
	((uint32_t *)(&QP_x_2))[1] = 0x02020202 * QP;  
 
	/* MMX assembler to compute DC_on */ 
	__asm { 
		push eax 
		push ebx 
		 
		mov eax, ptr1 
		mov ebx, ptr2 
 
		movq     mm0, [eax]               /* mm0 = v[l1]                   */ 
		movq     mm1, mm0                 /* mm1 = v[l1]                   */ 
		movq     mm2, [ebx]               /* mm2 = v[l8]                   */ 
		psubusb  mm0, mm2                 /* mm0 -= mm2                    */ 
		psubusb  mm2, mm1                 /* mm2 -= mm1                    */ 
		por      mm0, mm2                 /* mm0 |= mm2                    */ 
		psubusb  mm0, QP_x_2              /* mm0 -= 2 * QP                 */ 
		movq     mm1, mm0                 /* mm1 = mm0                     */ 
		psrlq    mm0, 32                  /* shift mm0 right 32 bits       */ 
		por      mm0, mm1                 /*                               */ 
		movd     DC_on, mm0               /* this is actually !DC_on       */ 
 
		pop ebx 
		pop eax 
 
	}; 
				 
	DC_on = !DC_on; /* the above assembler computes the opposite sense! */ 
	 
	#ifdef PP_SELF_CHECK 
	if (DC_on != DC_on2) { 
		printf("ERROR: MMX version of DC_on is incorrect\n"); 
	} 
	#endif 
 
	return DC_on; 
}