/src/aom/aom_dsp/binary_codes_reader.c
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * Copyright (c) 2017, Alliance for Open Media. All rights reserved |
3 | | * |
4 | | * This source code is subject to the terms of the BSD 2 Clause License and |
5 | | * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License |
6 | | * was not distributed with this source code in the LICENSE file, you can |
7 | | * obtain it at www.aomedia.org/license/software. If the Alliance for Open |
8 | | * Media Patent License 1.0 was not distributed with this source code in the |
9 | | * PATENTS file, you can obtain it at www.aomedia.org/license/patent. |
10 | | */ |
11 | | |
12 | | #include "aom_dsp/binary_codes_reader.h" |
13 | | #include "aom_dsp/recenter.h" |
14 | | |
15 | | uint16_t aom_read_primitive_quniform_(aom_reader *r, |
16 | 0 | uint16_t n ACCT_STR_PARAM) { |
17 | 0 | if (n <= 1) return 0; |
18 | 0 | const int l = get_msb(n) + 1; |
19 | 0 | const int m = (1 << l) - n; |
20 | 0 | const int v = aom_read_literal(r, l - 1, ACCT_STR_NAME); |
21 | 0 | return v < m ? v : (v << 1) - m + aom_read_bit(r, ACCT_STR_NAME); |
22 | 0 | } |
23 | | |
24 | | // Decode finite subexponential code that for a symbol v in [0, n-1] with |
25 | | // parameter k |
26 | | uint16_t aom_read_primitive_subexpfin_(aom_reader *r, uint16_t n, |
27 | 0 | uint16_t k ACCT_STR_PARAM) { |
28 | 0 | int i = 0; |
29 | 0 | int mk = 0; |
30 | |
|
31 | 0 | while (1) { |
32 | 0 | int b = (i ? k + i - 1 : k); |
33 | 0 | int a = (1 << b); |
34 | |
|
35 | 0 | if (n <= mk + 3 * a) { |
36 | 0 | return aom_read_primitive_quniform(r, n - mk, ACCT_STR_NAME) + mk; |
37 | 0 | } |
38 | | |
39 | 0 | if (!aom_read_bit(r, ACCT_STR_NAME)) { |
40 | 0 | return aom_read_literal(r, b, ACCT_STR_NAME) + mk; |
41 | 0 | } |
42 | | |
43 | 0 | i = i + 1; |
44 | 0 | mk += a; |
45 | 0 | } |
46 | | |
47 | 0 | assert(0); |
48 | 0 | return 0; |
49 | 0 | } |
50 | | |
51 | | uint16_t aom_read_primitive_refsubexpfin_(aom_reader *r, uint16_t n, uint16_t k, |
52 | 0 | uint16_t ref ACCT_STR_PARAM) { |
53 | 0 | return inv_recenter_finite_nonneg( |
54 | 0 | n, ref, aom_read_primitive_subexpfin(r, n, k, ACCT_STR_NAME)); |
55 | 0 | } |