cinelerra/byteorder.h

   1 #ifndef BYTEORDER_H
   2 #define BYTEORDER_H
   3
   4 #include <sys/types.h>
   5
   6 inline int get_byte_order()
   7 {                // 1 if little endian
   8         return (*(u_int32_t*)"a   ") & 0x00000001;
   9 }
  10
  11 #define SWAP_ITERATE \
  12                                         byte1 = buffer1[i]; \
  13                                 byte2 = buffer2[i]; \
  14                                 buffer1[i] = byte2; \
  15                                 buffer2[i] = byte1; \
  16                                         i += 2;
  17
  18 #define SWAP_24BIT_ITERATE \
  19                                         byte1 = buffer1[i]; \
  20                                 byte2 = buffer2[i]; \
  21                                 byte3 = buffer3[i]; \
  22                                 buffer1[i] = byte3; \
  23                                 buffer2[i] = byte2; \
  24                                 buffer3[i] = byte1; \
  25                                 i += 3;
  26
  27 #define SWAP_32BIT_ITERATE \
  28                                         byte1 = buffer1[i]; \
  29                                 byte2 = buffer2[i]; \
  30                                 byte3 = buffer3[i]; \
  31                                 byte4 = buffer4[i]; \
  32                                 buffer1[i] = byte4; \
  33                                 buffer2[i] = byte1; \
  34                                 buffer3[i] = byte2; \
  35                                 buffer4[i] = byte3; \
  36                                 i += 4;
  37
  38 inline int swap_bytes(int wordsize, unsigned char *buffer, long len)
  39 {
  40         register unsigned char byte1, byte2, byte3, byte4;
  41         register unsigned char *buffer1 = buffer;
  42         register unsigned char *buffer2 = buffer + 1;
  43         register unsigned char *buffer3 = buffer + 2;
  44         register unsigned char *buffer4 = buffer + 3;
  45
  46         register long i = 0, j = 0, k = 0;
  47
  48 //printf("swap bytes\n");
  49
  50         switch(wordsize)
  51         {
  52                 case 1:
  53                         return 0;
  54                         break;
  55
  56                 case 2:
  57                         len -= 8;
  58                         while(i < len){
  59                         SWAP_ITERATE
  60                         SWAP_ITERATE
  61                         SWAP_ITERATE
  62                         SWAP_ITERATE
  63                         }
  64
  65                         len += 8;
  66                         while(i < len){
  67                         SWAP_ITERATE
  68                         }
  69                         return 0;
  70                         break;
  71
  72                 case 3:
  73                         len -= 12;
  74                         while(i < len){
  75                         SWAP_24BIT_ITERATE
  76                         SWAP_24BIT_ITERATE
  77                         SWAP_24BIT_ITERATE
  78                         SWAP_24BIT_ITERATE
  79                         }
  80
  81                         len += 12;
  82                         while(i < len){
  83                         SWAP_24BIT_ITERATE
  84                         }
  85                         return 0;
  86                         break;
  87
  88                 case 4:
  89                         len -= 16;
  90                         while(i < len)
  91                         {
  92                                 SWAP_32BIT_ITERATE
  93                                 SWAP_32BIT_ITERATE
  94                                 SWAP_32BIT_ITERATE
  95                                 SWAP_32BIT_ITERATE
  96                         }
  97
  98                         len += 16;
  99                         while(i < len)
 100                         {
 101                                 SWAP_32BIT_ITERATE
 102                         }
 103                         return 0;
 104                         break;
 105         }
 106         return 1;
 107 }
 108
 109 #endif
 110 /*
 111 //      Local Variables:
 112 //      mode: C++
 113 //      c-file-style: "linux"
 114 //      End:
 115 */