/*****************************************************************************
*
* XVID MPEG-4 VIDEO CODEC
* - cbp function (zero block flags) -
*
* Copyright (C) 2001-2002 - Edouard Gomez
*
* 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
* (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., 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 1.9 2002/12/28 13:53:08 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
*/
uint32_t
calc_cbp_c(const int16_t codes[6 * 64])
{
uint32_t 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);
break;
}
}
if (codes[i * 64 + j] | codes[i * 64 + j + 1] | codes[i * 64 + j + 2])
cbp |= 1 << (5 - i);
}
return cbp;
}