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