1 | #ifndef TREES_H_ |
2 | #define TREES_H_ |
3 | |
4 | /* Constants */ |
5 | |
6 | #define DIST_CODE_LEN 512 |
7 | /* see definition of array dist_code in trees.c */ |
8 | |
9 | #define MAX_BL_BITS 7 |
10 | /* Bit length codes must not exceed MAX_BL_BITS bits */ |
11 | |
12 | #define REP_3_6 16 |
13 | /* repeat previous bit length 3-6 times (2 bits of repeat count) */ |
14 | |
15 | #define REPZ_3_10 17 |
16 | /* repeat a zero length 3-10 times (3 bits of repeat count) */ |
17 | |
18 | #define REPZ_11_138 18 |
19 | /* repeat a zero length 11-138 times (7 bits of repeat count) */ |
20 | |
21 | static const int [LENGTH_CODES] /* extra bits for each length code */ |
22 | = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0}; |
23 | |
24 | static const int [D_CODES] /* extra bits for each distance code */ |
25 | = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13}; |
26 | |
27 | static const int [BL_CODES] /* extra bits for each bit length code */ |
28 | = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; |
29 | |
30 | static const unsigned char bl_order[BL_CODES] |
31 | = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; |
32 | /* The lengths of the bit length codes are sent in order of decreasing |
33 | * probability, to avoid transmitting the lengths for unused bit length codes. |
34 | */ |
35 | |
36 | |
37 | /* Function definitions */ |
38 | void gen_codes (ct_data *tree, int max_code, uint16_t *bl_count); |
39 | |
40 | #endif |
41 | |