a359bb4f
 Hu Chunming
调通可正常运行 -- 初版
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/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* @ingroup lavu
* Utility Preprocessor macros
*/
#ifndef AVUTIL_MACROS_H
#define AVUTIL_MACROS_H
#include "libavutil/avconfig.h"
#if AV_HAVE_BIGENDIAN
# define AV_NE(be, le) (be)
#else
# define AV_NE(be, le) (le)
#endif
/**
* Comparator.
* For two numerical expressions x and y, gives 1 if x > y, -1 if x < y, and 0
* if x == y. This is useful for instance in a qsort comparator callback.
* Furthermore, compilers are able to optimize this to branchless code, and
* there is no risk of overflow with signed types.
* As with many macros, this evaluates its argument multiple times, it thus
* must not have a side-effect.
*/
#define FFDIFFSIGN(x,y) (((x)>(y)) - ((x)<(y)))
#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
#define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
#define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
#define FFSWAP(type,a,b) do{type SWAP_tmp= b; b= a; a= SWAP_tmp;}while(0)
#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
#define MKTAG(a,b,c,d) ((a) | ((b) << 8) | ((c) << 16) | ((unsigned)(d) << 24))
#define MKBETAG(a,b,c,d) ((d) | ((c) << 8) | ((b) << 16) | ((unsigned)(a) << 24))
/**
* @addtogroup preproc_misc Preprocessor String Macros
*
* String manipulation macros
*
* @{
*/
#define AV_STRINGIFY(s) AV_TOSTRING(s)
#define AV_TOSTRING(s) #s
#define AV_GLUE(a, b) a ## b
#define AV_JOIN(a, b) AV_GLUE(a, b)
/**
* @}
*/
#define AV_PRAGMA(s) _Pragma(#s)
#define FFALIGN(x, a) (((x)+(a)-1)&~((a)-1))
#endif /* AVUTIL_MACROS_H */
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