--- cbp.c 2002/11/17 00:57:57 1.8 +++ cbp.c 2003/06/09 13:51:56 1.10.2.2 @@ -1,96 +1,112 @@ /***************************************************************************** * * XVID MPEG-4 VIDEO CODEC - * - cbp function (zero block flags) - + * - CBP related function - * - * Copyright (C) 2001-2002 - Edouard Gomez + * Copyright(C) 2002-2003 Edouard Gomez + * 2003 Christoph Lampert * - * This file is part of XviD, a free MPEG-4 video encoder/decoder - * - * 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 + * 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 + * 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 + * along with this program ; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * - * Under section 8 of the GNU General Public License, the copyright - * holders of XVID explicitly forbid distribution in the following - * countries: - * - * - Japan - * - United States of America - * - * Linking XviD statically or dynamically with other modules is making a - * combined work based on XviD. Thus, the terms and conditions of the - * GNU General Public License cover the whole combination. - * - * As a special exception, the copyright holders of XviD give you - * permission to link XviD with independent modules that communicate with - * XviD solely through the VFW1.1 and DShow interfaces, regardless of the - * license terms of these independent modules, and to copy and distribute - * the resulting combined work under terms of your choice, provided that - * every copy of the combined work is accompanied by a complete copy of - * the source code of XviD (the version of XviD used to produce the - * combined work), being distributed under the terms of the GNU General - * Public License plus this exception. An independent module is a module - * which is not derived from or based on XviD. - * - * Note that people who make modified versions of XviD are not obligated - * to grant this special exception for their modified versions; it is - * their choice whether to do so. The GNU General Public License gives - * permission to release a modified version without this exception; this - * exception also makes it possible to release a modified version which - * carries forward this exception. - * - * $Id: cbp.c,v 1.8 2002/11/17 00:57:57 edgomez Exp $ + * $Id: cbp.c,v 1.10.2.2 2003/06/09 13:51:56 edgomez Exp $ * ****************************************************************************/ #include "../portab.h" #include "cbp.h" -/***************************************************************************** - * Global function pointer - ****************************************************************************/ - cbpFuncPtr calc_cbp; -/***************************************************************************** - * Functions - ****************************************************************************/ - /* * Returns a field of bits that indicates non zero ac blocks * for this macro block */ + +/* naive C */ uint32_t -calc_cbp_c(const int16_t codes[6 * 64]) +calc_cbp_plain(const int16_t codes[6 * 64]) { - uint32_t i, j; + int i, j; uint32_t cbp = 0; for (i = 0; i < 6; i++) { - for (j = 1; j < 61; j += 4) { - if (codes[i * 64 + j] | codes[i * 64 + j + 1] | - codes[i * 64 + j + 2] | codes[i * 64 + j + 3]) { - cbp |= 1 << (5 - i); + for (j=1; j<64;j++) { + if (codes[64*i+j]) { + cbp |= 1 << (5-i); break; } } + } + return cbp; +} + +/* optimized C */ +uint32_t +calc_cbp_c(const int16_t codes[6 * 64]) +{ + unsigned int i=6; + uint32_t cbp = 0; + +/* uses fixed relation: 4*codes = 1*codes64 */ +/* if prototype is changed (e.g. from int16_t to something like int32) this routine + has to be changed! */ + + do { + uint64_t *codes64 = (uint64_t*)codes; /* the compiler doesn't really make this */ + uint32_t *codes32 = (uint32_t*)codes; /* variables, just "addressing modes" */ + + cbp += cbp; + if (codes[1] || codes32[1]) { + cbp++; + } + else if (codes64[1] | codes64[2] | codes64[3]) { + cbp++; + } + else if (codes64[4] | codes64[5] | codes64[6] | codes64[7]) { + cbp++; + } + else if (codes64[8] | codes64[9] | codes64[10] | codes64[11]) { + cbp++; + } + else if (codes64[12] | codes64[13] | codes64[14] | codes64[15]) { + cbp++; + } + codes += 64; + i--; + } while (i != 0); - if (codes[i * 64 + j] | codes[i * 64 + j + 1] | codes[i * 64 + j + 2]) - cbp |= 1 << (5 - i); + return cbp; +} + + + +/* older code maybe better on some plattforms? */ +#if 0 + for (i = 5; i >= 0; i--) { + if (codes[1] | codes[2] | codes[3]) + cbp |= 1 << i; + else { + for (j = 4; j <= 56; j+=4) /* [60],[61],[62],[63] are last */ + if (codes[j] | codes[j+1] | codes[j+2] | codes[j+3]) { + cbp |= 1 << i; + break; + } + } + codes += 64; } return cbp; - -} +#endif