libavutil/bswap.h

   1 /*
   2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /**
  22  * @file libavutil/bswap.h
  23  * byte swapping routines
  24  */
  25
  26 #ifndef AVUTIL_BSWAP_H
  27 #define AVUTIL_BSWAP_H
  28
  29 #include <stdint.h>
  30 #include "config.h"
  31 #include "common.h"
  32
  33 #if   ARCH_ARM
  34 #   include "arm/bswap.h"
  35 #elif ARCH_BFIN
  36 #   include "bfin/bswap.h"
  37 #elif ARCH_SH4
  38 #   include "sh4/bswap.h"
  39 #elif ARCH_X86
  40 #   include "x86/bswap.h"
  41 #endif
  42
  43 #ifndef bswap_16
  44 static av_always_inline av_const uint16_t bswap_16(uint16_t x)
  45 {
  46     x= (x>>8) | (x<<8);
  47     return x;
  48 }
  49 #endif
  50
  51 #ifndef bswap_32
  52 static av_always_inline av_const uint32_t bswap_32(uint32_t x)
  53 {
  54     x= ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF);
  55     x= (x>>16) | (x<<16);
  56     return x;
  57 }
  58 #endif
  59
  60 #ifndef bswap_64
  61 static inline uint64_t av_const bswap_64(uint64_t x)
  62 {
  63 #if 0
  64     x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL);
  65     x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL);
  66     return (x>>32) | (x<<32);
  67 #else
  68     union {
  69         uint64_t ll;
  70         uint32_t l[2];
  71     } w, r;
  72     w.ll = x;
  73     r.l[0] = bswap_32 (w.l[1]);
  74     r.l[1] = bswap_32 (w.l[0]);
  75     return r.ll;
  76 #endif
  77 }
  78 #endif
  79
  80 // be2me ... big-endian to machine-endian
  81 // le2me ... little-endian to machine-endian
  82
  83 #ifdef WORDS_BIGENDIAN
  84 #define be2me_16(x) (x)
  85 #define be2me_32(x) (x)
  86 #define be2me_64(x) (x)
  87 #define le2me_16(x) bswap_16(x)
  88 #define le2me_32(x) bswap_32(x)
  89 #define le2me_64(x) bswap_64(x)
  90 #else
  91 #define be2me_16(x) bswap_16(x)
  92 #define be2me_32(x) bswap_32(x)
  93 #define be2me_64(x) bswap_64(x)
  94 #define le2me_16(x) (x)
  95 #define le2me_32(x) (x)
  96 #define le2me_64(x) (x)
  97 #endif
  98
  99 #endif /* AVUTIL_BSWAP_H */