Harald Welte | d83c513 | 2016-10-26 09:38:24 +0200 | [diff] [blame] | 1 | #include <stdint.h> |
| 2 | #include "flip_bits.h" |
| 3 | |
| 4 | static uint8_t flip_table[256]; |
| 5 | |
| 6 | void init_flip_bits(void) |
| 7 | { |
| 8 | int i,k; |
| 9 | |
| 10 | for (i = 0 ; i < 256 ; i++) { |
| 11 | uint8_t sample = 0 ; |
| 12 | for (k = 0; k<8; k++) { |
| 13 | if ( i & 1 << k ) sample |= 0x80 >> k; |
| 14 | } |
| 15 | flip_table[i] = sample; |
| 16 | } |
| 17 | } |
| 18 | |
| 19 | uint8_t *flip_buf_bits(uint8_t *buf, int len) |
| 20 | { |
| 21 | int i; |
| 22 | uint8_t *start = buf; |
| 23 | |
| 24 | for (i = 0 ; i < len; i++) { |
| 25 | buf[i] = flip_table[(uint8_t)buf[i]]; |
| 26 | } |
| 27 | |
| 28 | return start; |
| 29 | } |