deblock_horiz_dc_on.c

MPEG4编解码的C语言源代码

/**************************************************************************
 *                                                                        *
 * 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 <[e-mail]>
*
**/

/***

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_horiz_DC_on(uint8_t *v, int stride, int QP) {
	/* 99% of the time, this test turns out the same as the |max-min| strategy in the standard */
	return (ABS(v[1]-v[8]) < 2*QP);
}