bswap.h
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上传日期:2022-07-08
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文件大小:2k
- /*
- * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
- *
- * 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 bswap.h
- * byte swapping routines
- */
- #ifndef AVUTIL_BSWAP_H
- #define AVUTIL_BSWAP_H
- //#include <stdint.h>
- #include "config.h"
- #include "common.h"
- /*
- #if defined(ARCH_ARM)
- # include "arm/bswap.h"
- #elif defined(ARCH_BFIN)
- # include "bfin/bswap.h"
- #elif defined(ARCH_SH4)
- # include "sh4/bswap.h"
- #elif defined(ARCH_X86)
- # include "x86/bswap.h"
- #endif
- */
- #ifndef bswap_16
- static av_always_inline av_const uint16_t bswap_16(uint16_t x)
- {
- x= (x>>8) | (x<<8);
- return x;
- }
- #endif
- #ifndef bswap_32
- static av_always_inline av_const uint32_t bswap_32(uint32_t x)
- {
- x= ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF);
- x= (x>>16) | (x<<16);
- return x;
- }
- #endif
- #ifndef bswap_64
- static inline uint64_t av_const bswap_64(uint64_t x)
- {
- #if 0
- x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL);
- x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL);
- return (x>>32) | (x<<32);
- #else
- union {
- uint64_t ll;
- uint32_t l[2];
- } w, r;
- w.ll = x;
- r.l[0] = bswap_32 (w.l[1]);
- r.l[1] = bswap_32 (w.l[0]);
- return r.ll;
- #endif
- }
- #endif
- // be2me ... BigEndian to MachineEndian
- // le2me ... LittleEndian to MachineEndian
- #ifdef WORDS_BIGENDIAN
- #define be2me_16(x) (x)
- #define be2me_32(x) (x)
- #define be2me_64(x) (x)
- #define le2me_16(x) bswap_16(x)
- #define le2me_32(x) bswap_32(x)
- #define le2me_64(x) bswap_64(x)
- #else
- #define be2me_16(x) bswap_16(x)
- #define be2me_32(x) bswap_32(x)
- #define be2me_64(x) bswap_64(x)
- #define le2me_16(x) (x)
- #define le2me_32(x) (x)
- #define le2me_64(x) (x)
- #endif
- #endif /* AVUTIL_BSWAP_H */