cinelerra-5.1/cinelerra/byteorder.h

   1
   2 /*
   3  * CINELERRA
   4  * Copyright (C) 2008 Adam Williams <broadcast at earthling dot net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program 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
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21
  22 #ifndef BYTEORDER_H
  23 #define BYTEORDER_H
  24
  25 #include <sys/types.h>
  26
  27 inline int get_byte_order()
  28 {                // 1 if little endian
  29         return (*(const u_int32_t*)"a   ") & 0x00000001;
  30 }
  31
  32 #define SWAP_ITERATE \
  33         byte1 = buffer1[i]; \
  34         byte2 = buffer2[i]; \
  35         buffer1[i] = byte2; \
  36         buffer2[i] = byte1; \
  37         i += 2;
  38
  39 #define SWAP_24BIT_ITERATE \
  40         byte1 = buffer1[i]; \
  41         byte2 = buffer2[i]; \
  42         byte3 = buffer3[i]; \
  43         buffer1[i] = byte3; \
  44         buffer2[i] = byte2; \
  45         buffer3[i] = byte1; \
  46         i += 3;
  47
  48 #define SWAP_32BIT_ITERATE \
  49         byte1 = buffer1[i]; \
  50         byte2 = buffer2[i]; \
  51         byte3 = buffer3[i]; \
  52         byte4 = buffer4[i]; \
  53         buffer1[i] = byte4; \
  54         buffer2[i] = byte1; \
  55         buffer3[i] = byte2; \
  56         buffer4[i] = byte3; \
  57         i += 4;
  58
  59 inline int swap_bytes(int wordsize, unsigned char *buffer, long len)
  60 {
  61         register unsigned char byte1, byte2, byte3, byte4;
  62         register unsigned char *buffer1 = buffer;
  63         register unsigned char *buffer2 = buffer + 1;
  64         register unsigned char *buffer3 = buffer + 2;
  65         register unsigned char *buffer4 = buffer + 3;
  66         register long i = 0;
  67
  68 //printf("swap bytes\n");
  69
  70         switch( wordsize ) {
  71         case 1:
  72                 return 0;
  73
  74         case 2:
  75                 len -= 8;
  76                 while( i < len ) {
  77                         SWAP_ITERATE
  78                         SWAP_ITERATE
  79                         SWAP_ITERATE
  80                         SWAP_ITERATE
  81                 }
  82
  83                 len += 8;
  84                 while( i < len ) {
  85                         SWAP_ITERATE
  86                 }
  87                 return 0;
  88
  89         case 3:
  90                 len -= 12;
  91                 while( i < len ) {
  92                         SWAP_24BIT_ITERATE
  93                         SWAP_24BIT_ITERATE
  94                         SWAP_24BIT_ITERATE
  95                         SWAP_24BIT_ITERATE
  96                 }
  97
  98                 len += 12;
  99                 while( i < len ) {
 100                         SWAP_24BIT_ITERATE
 101                 }
 102                 return 0;
 103
 104         case 4:
 105                 len -= 16;
 106                 while( i < len ) {
 107                         SWAP_32BIT_ITERATE
 108                         SWAP_32BIT_ITERATE
 109                         SWAP_32BIT_ITERATE
 110                         SWAP_32BIT_ITERATE
 111                 }
 112
 113                 len += 16;
 114                 while( i < len ) {
 115                         SWAP_32BIT_ITERATE
 116                 }
 117                 return 0;
 118         }
 119
 120         return 1;
 121 }
 122
 123 #endif