Commit | Line | Data |
---|---|---|
2ba45a60 DM |
1 | /* |
2 | * Shared functions between AMR codecs | |
3 | * | |
4 | * Copyright (c) 2010 Marcelo Galvao Povoa | |
5 | * | |
6 | * This file is part of FFmpeg. | |
7 | * | |
8 | * FFmpeg is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; either | |
11 | * version 2.1 of the License, or (at your option) any later version. | |
12 | * | |
13 | * FFmpeg is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with FFmpeg; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
21 | */ | |
22 | ||
23 | #ifndef AVCODEC_AMR_H | |
24 | #define AVCODEC_AMR_H | |
25 | ||
26 | #include <string.h> | |
27 | ||
28 | #include "avcodec.h" | |
29 | ||
30 | #ifdef AMR_USE_16BIT_TABLES | |
31 | #define R_TABLE_TYPE uint16_t | |
32 | #else | |
33 | #define R_TABLE_TYPE uint8_t | |
34 | #endif | |
35 | ||
36 | /** | |
37 | * Fill the frame structure variables from bitstream by parsing the | |
38 | * given reordering table that uses the following format: | |
39 | * | |
40 | * Each field (16 bits) in the AMR Frame is stored as: | |
41 | * - one byte for the number of bits in the field | |
42 | * - one byte for the field index | |
43 | * - then, one byte for each bit of the field (from most-significant to least) | |
44 | * of the position of that bit in the AMR frame. | |
45 | * | |
46 | * @param out pointer to the frame struct | |
47 | * @param size the size in bytes of the frame struct | |
48 | * @param data input bitstream after the frame header | |
49 | * @param ord_table the reordering table as above | |
50 | */ | |
51 | static inline void ff_amr_bit_reorder(uint16_t *out, int size, | |
52 | const uint8_t *data, | |
53 | const R_TABLE_TYPE *ord_table) | |
54 | { | |
55 | int field_size; | |
56 | ||
57 | memset(out, 0, size); | |
58 | while ((field_size = *ord_table++)) { | |
59 | int field = 0; | |
60 | int field_offset = *ord_table++; | |
61 | while (field_size--) { | |
62 | int bit = *ord_table++; | |
63 | field <<= 1; | |
64 | field |= data[bit >> 3] >> (bit & 7) & 1; | |
65 | } | |
66 | out[field_offset >> 1] = field; | |
67 | } | |
68 | } | |
69 | ||
70 | #endif /* AVCODEC_AMR_H */ |