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547b7bcbb7
The normal byteswap functions might use inline asm which is suboptimal with constants (and cannot be used in static initialisers), so special macros for constants only is needed. We should not rely on the gcc __builtin_constant_p() test since it is not always available. Originally committed as revision 22990 to svn://svn.ffmpeg.org/ffmpeg/trunk
119 lines
3.0 KiB
C
119 lines
3.0 KiB
C
/*
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* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* byte swapping routines
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*/
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#ifndef AVUTIL_BSWAP_H
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#define AVUTIL_BSWAP_H
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#include <stdint.h>
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#include "config.h"
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#include "attributes.h"
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#if ARCH_ARM
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# include "arm/bswap.h"
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#elif ARCH_AVR32
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# include "avr32/bswap.h"
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#elif ARCH_BFIN
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# include "bfin/bswap.h"
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#elif ARCH_SH4
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# include "sh4/bswap.h"
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#elif ARCH_X86
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# include "x86/bswap.h"
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#endif
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#define AV_BSWAP16C(x) (((x) << 8 & 0xff00) | ((x) >> 8 & 0x00ff))
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#define AV_BSWAP32C(x) (AV_BSWAP16C(x) << 16 | AV_BSWAP16C(x >> 16))
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#define AV_BSWAP64C(x) (AV_BSWAP32C(x) << 32 | AV_BSWAP32C(x >> 32))
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#define AV_BSWAPC(s, x) AV_BSWAP##s##C(x)
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#ifndef bswap_16
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static av_always_inline av_const uint16_t bswap_16(uint16_t x)
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{
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x= (x>>8) | (x<<8);
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return x;
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}
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#endif
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#ifndef bswap_32
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static av_always_inline av_const uint32_t bswap_32(uint32_t x)
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{
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x= ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF);
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x= (x>>16) | (x<<16);
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return x;
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}
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#endif
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#ifndef bswap_64
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static inline uint64_t av_const bswap_64(uint64_t x)
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{
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#if 0
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x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL);
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x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL);
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return (x>>32) | (x<<32);
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#else
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union {
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uint64_t ll;
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uint32_t l[2];
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} w, r;
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w.ll = x;
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r.l[0] = bswap_32 (w.l[1]);
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r.l[1] = bswap_32 (w.l[0]);
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return r.ll;
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#endif
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}
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#endif
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// be2me ... big-endian to machine-endian
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// le2me ... little-endian to machine-endian
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#if HAVE_BIGENDIAN
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#define be2me_16(x) (x)
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#define be2me_32(x) (x)
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#define be2me_64(x) (x)
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#define le2me_16(x) bswap_16(x)
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#define le2me_32(x) bswap_32(x)
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#define le2me_64(x) bswap_64(x)
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#define AV_BE2MEC(s, x) (x)
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#define AV_LE2MEC(s, x) AV_BSWAPC(s, x)
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#else
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#define be2me_16(x) bswap_16(x)
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#define be2me_32(x) bswap_32(x)
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#define be2me_64(x) bswap_64(x)
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#define le2me_16(x) (x)
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#define le2me_32(x) (x)
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#define le2me_64(x) (x)
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#define AV_BE2MEC(s, x) AV_BSWAPC(s, x)
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#define AV_LE2MEC(s, x) (x)
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#endif
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#define AV_BE2ME16C(x) AV_BE2MEC(16, x)
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#define AV_BE2ME32C(x) AV_BE2MEC(32, x)
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#define AV_BE2ME64C(x) AV_BE2MEC(64, x)
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#define AV_LE2ME16C(x) AV_LE2MEC(16, x)
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#define AV_LE2ME32C(x) AV_LE2MEC(32, x)
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#define AV_LE2ME64C(x) AV_LE2MEC(64, x)
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#endif /* AVUTIL_BSWAP_H */
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