cbp_mmx.asm

MPEG-4编解码的实现(包括MPEG4视音频编解码)

;/**************************************************************************
; *
; *	XVID MPEG-4 VIDEO CODEC
; *	mmx cbp calc
; *
; *	This program 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.
; *
; *	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., 675 Mass Ave, Cambridge, MA 02139, USA.
; *
; *************************************************************************/

;/**************************************************************************
; *
; *	History:
; *
; *     22.03.2002      0.01          ; Min Chen <[e-mail]>
; *                                   ; use 386 cpu's 'BTS' to replace 'cbp |= 1 << (edx-1)'
; *	24.11.2001	inital version; (c)2001 peter ross <[e-mail]>
; *
; *************************************************************************/


bits 32

section .data

%macro cglobal 1
%ifdef PREFIX
global _%1
%define %1 _%1
%else
global %1
%endif
%endmacro

ignore_dc	dw		0, -1, -1, -1


section .text


;===========================================================================
;
; uint32_t calc_cbp_mmx(const int16_t coeff[6][64]);
;
;===========================================================================

align 16
cglobal calc_cbp_mmx
calc_cbp_mmx
				push	ebx
				push	ecx
				push	edx
				push	esi

                mov     esi, [esp + 16 + 4]              ; coeff
				movq	mm7, [ignore_dc]

				xor		eax, eax		; cbp = 0
				mov		edx, 6
.loop
                movq	mm0, [esi]
				pand	mm0, mm7
                movq	mm1, [esi+8]

                por     mm0, [esi+16]
                por     mm1, [esi+24]

                por     mm0, [esi+32]
                por     mm1, [esi+40]

                por     mm0, [esi+48]
                por     mm1, [esi+56]

                por     mm0, [esi+64]
                por     mm1, [esi+72]

                por     mm0, [esi+80]
                por     mm1, [esi+88]

                por     mm0, [esi+96]
                por     mm1, [esi+104]

                por     mm0, [esi+112]
                por     mm1, [esi+120]

                por     mm0, mm1
                movq    mm1, mm0
                psrlq   mm1, 32
                por     mm0, mm1
				movd    ebx, mm0

				add		esi, 128

				or		ebx, ebx
				jz		.iterate

				; cbp |= 1 << (edx-1)
				
                                ; Change by Chenm001 <[e-mail]>
                                ;mov             ecx, edx
                                ;dec             ecx
                                ;mov             ebx, 1
                                ;shl             ebx, cl
                                ;or              eax, ebx
                                lea             ebx,[edx-1]
                                bts             eax,ebx

.iterate		dec	edx
				jnz		.loop

				pop	esi
				pop	edx
				pop	ecx
				pop	ebx
				
				ret