Line | Branch | Exec | Source |
---|---|---|---|
1 | /* | ||
2 | * This file is part of FFmpeg. | ||
3 | * | ||
4 | * FFmpeg is free software; you can redistribute it and/or | ||
5 | * modify it under the terms of the GNU Lesser General Public | ||
6 | * License as published by the Free Software Foundation; either | ||
7 | * version 2.1 of the License, or (at your option) any later version. | ||
8 | * | ||
9 | * FFmpeg is distributed in the hope that it will be useful, | ||
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
12 | * Lesser General Public License for more details. | ||
13 | * | ||
14 | * You should have received a copy of the GNU Lesser General Public | ||
15 | * License along with FFmpeg; if not, write to the Free Software | ||
16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
17 | */ | ||
18 | |||
19 | /** | ||
20 | * @file | ||
21 | * leb128 handling implementations | ||
22 | */ | ||
23 | |||
24 | #ifndef AVCODEC_LEB_H | ||
25 | #define AVCODEC_LEB_H | ||
26 | |||
27 | #include "get_bits.h" | ||
28 | |||
29 | /** | ||
30 | * Read a unsigned integer coded as a variable number of up to eight | ||
31 | * little-endian bytes, where the MSB in a byte signals another byte | ||
32 | * must be read. | ||
33 | * All coded bits are read, but values > UINT_MAX are truncated. | ||
34 | */ | ||
35 | 13389 | static inline unsigned get_leb(GetBitContext *s) { | |
36 | 13389 | int more, i = 0; | |
37 | 13389 | unsigned leb = 0; | |
38 | |||
39 | do { | ||
40 | 15944 | int byte = get_bits(s, 8); | |
41 | 15944 | unsigned bits = byte & 0x7f; | |
42 | 15944 | more = byte & 0x80; | |
43 |
2/2✓ Branch 0 taken 15880 times.
✓ Branch 1 taken 64 times.
|
15944 | if (i <= 4) |
44 | 15880 | leb |= bits << (i * 7); | |
45 |
2/2✓ Branch 0 taken 21 times.
✓ Branch 1 taken 15923 times.
|
15944 | if (++i == 8) |
46 | 21 | break; | |
47 |
2/2✓ Branch 0 taken 2555 times.
✓ Branch 1 taken 13368 times.
|
15923 | } while (more); |
48 | |||
49 | 13389 | return leb; | |
50 | } | ||
51 | |||
52 | /** | ||
53 | * Read a unsigned integer coded as a variable number of up to eight | ||
54 | * little-endian bytes, where the MSB in a byte signals another byte | ||
55 | * must be read. | ||
56 | */ | ||
57 | 3501 | static inline int64_t get_leb128(GetBitContext *gb) { | |
58 | 3501 | int64_t ret = 0; | |
59 | |||
60 |
2/2✓ Branch 0 taken 4204 times.
✓ Branch 1 taken 6 times.
|
4210 | for (int i = 0; i < 8; i++) { |
61 | 4204 | int byte = get_bits(gb, 8); | |
62 | 4204 | ret |= (int64_t)(byte & 0x7f) << (i * 7); | |
63 |
2/2✓ Branch 0 taken 3495 times.
✓ Branch 1 taken 709 times.
|
4204 | if (!(byte & 0x80)) |
64 | 3495 | break; | |
65 | } | ||
66 | |||
67 | 3501 | return ret; | |
68 | } | ||
69 | |||
70 | #endif /* AVCODEC_LEB_H */ | ||
71 |