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
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/*
* Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* audio conversion routines
*/
#include "avstring.h"
#include "avutil.h"
#include "audioconvert.h"
static const char * const channel_names[] = {
[0] = "FL", /* front left */
[1] = "FR", /* front right */
[2] = "FC", /* front center */
[3] = "LFE", /* low frequency */
[4] = "BL", /* back left */
[5] = "BR", /* back right */
[6] = "FLC", /* front left-of-center */
[7] = "FRC", /* front right-of-center */
[8] = "BC", /* back-center */
[9] = "SL", /* side left */
[10] = "SR", /* side right */
[11] = "TC", /* top center */
[12] = "TFL", /* top front left */
[13] = "TFC", /* top front center */
[14] = "TFR", /* top front right */
[15] = "TBL", /* top back left */
[16] = "TBC", /* top back center */
[17] = "TBR", /* top back right */
[29] = "DL", /* downmix left */
[30] = "DR", /* downmix right */
};
static const char *get_channel_name(int channel_id)
{
if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
return NULL;
return channel_names[channel_id];
}
static const struct {
const char *name;
int nb_channels;
int64_t layout;
} channel_layout_map[] = {
{ "mono", 1, AV_CH_LAYOUT_MONO },
{ "stereo", 2, AV_CH_LAYOUT_STEREO },
{ "4.0", 4, AV_CH_LAYOUT_4POINT0 },
{ "quad", 4, AV_CH_LAYOUT_QUAD },
{ "5.0(side)", 5, AV_CH_LAYOUT_5POINT0 },
{ "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },
{ "5.1(side)", 6, AV_CH_LAYOUT_5POINT1 },
{ "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },
{ "5.1+downmix", 8, AV_CH_LAYOUT_5POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
{ "7.1", 8, AV_CH_LAYOUT_7POINT1 },
{ "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
{ "7.1+downmix", 10, AV_CH_LAYOUT_7POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
{ 0 }
};
int64_t av_get_channel_layout(const char *name)
{
int i = 0;
do {
if (!strcmp(channel_layout_map[i].name, name))
return channel_layout_map[i].layout;
i++;
} while (channel_layout_map[i].name);
return 0;
}
void av_get_channel_layout_string(char *buf, int buf_size,
int nb_channels, int64_t channel_layout)
{
int i;
if (nb_channels <= 0)
nb_channels = av_get_channel_layout_nb_channels(channel_layout);
for (i = 0; channel_layout_map[i].name; i++)
if (nb_channels == channel_layout_map[i].nb_channels &&
channel_layout == channel_layout_map[i].layout) {
av_strlcpy(buf, channel_layout_map[i].name, buf_size);
return;
}
snprintf(buf, buf_size, "%d channels", nb_channels);
if (channel_layout) {
int i, ch;
av_strlcat(buf, " (", buf_size);
for (i = 0, ch = 0; i < 64; i++) {
if ((channel_layout & (1L << i))) {
const char *name = get_channel_name(i);
if (name) {
if (ch > 0)
av_strlcat(buf, "|", buf_size);
av_strlcat(buf, name, buf_size);
}
ch++;
}
}
av_strlcat(buf, ")", buf_size);
}
}
int av_get_channel_layout_nb_channels(int64_t channel_layout)
{
int count;
uint64_t x = channel_layout;
for (count = 0; x; count++)
x &= x-1; // unset lowest set bit
return count;
}
|
