d6a4b8a4f23728f9b3f55d5f203ca81ec024a664
[libav.git] / libavutil / audioconvert.c
1 /*
2 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of Libav.
5 *
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 /**
22 * @file
23 * audio conversion routines
24 */
25
26 #include "avstring.h"
27 #include "avutil.h"
28 #include "audioconvert.h"
29
30 static const char * const channel_names[] = {
31 "FL", "FR", "FC", "LFE", "BL", "BR", "FLC", "FRC",
32 "BC", "SL", "SR", "TC", "TFL", "TFC", "TFR", "TBL",
33 "TBC", "TBR",
34 [29] = "DL",
35 [30] = "DR",
36 };
37
38 static const char *get_channel_name(int channel_id)
39 {
40 if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
41 return NULL;
42 return channel_names[channel_id];
43 }
44
45 static const struct {
46 const char *name;
47 int nb_channels;
48 int64_t layout;
49 } channel_layout_map[] = {
50 { "mono", 1, AV_CH_LAYOUT_MONO },
51 { "stereo", 2, AV_CH_LAYOUT_STEREO },
52 { "4.0", 4, AV_CH_LAYOUT_4POINT0 },
53 { "quad", 4, AV_CH_LAYOUT_QUAD },
54 { "5.0", 5, AV_CH_LAYOUT_5POINT0 },
55 { "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },
56 { "5.1", 6, AV_CH_LAYOUT_5POINT1 },
57 { "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },
58 { "5.1+downmix", 8, AV_CH_LAYOUT_5POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
59 { "7.1", 8, AV_CH_LAYOUT_7POINT1 },
60 { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
61 { "7.1+downmix", 10, AV_CH_LAYOUT_7POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
62 { 0 }
63 };
64
65 int64_t av_get_channel_layout(const char *name)
66 {
67 int i = 0;
68 do {
69 if (!strcmp(channel_layout_map[i].name, name))
70 return channel_layout_map[i].layout;
71 i++;
72 } while (channel_layout_map[i].name);
73
74 return 0;
75 }
76
77 void av_get_channel_layout_string(char *buf, int buf_size,
78 int nb_channels, int64_t channel_layout)
79 {
80 int i;
81
82 if (nb_channels <= 0)
83 nb_channels = av_get_channel_layout_nb_channels(channel_layout);
84
85 for (i = 0; channel_layout_map[i].name; i++)
86 if (nb_channels == channel_layout_map[i].nb_channels &&
87 channel_layout == channel_layout_map[i].layout) {
88 av_strlcpy(buf, channel_layout_map[i].name, buf_size);
89 return;
90 }
91
92 snprintf(buf, buf_size, "%d channels", nb_channels);
93 if (channel_layout) {
94 int i, ch;
95 av_strlcat(buf, " (", buf_size);
96 for (i = 0, ch = 0; i < 64; i++) {
97 if ((channel_layout & (1L << i))) {
98 const char *name = get_channel_name(i);
99 if (name) {
100 if (ch > 0)
101 av_strlcat(buf, "|", buf_size);
102 av_strlcat(buf, name, buf_size);
103 }
104 ch++;
105 }
106 }
107 av_strlcat(buf, ")", buf_size);
108 }
109 }
110
111 int av_get_channel_layout_nb_channels(int64_t channel_layout)
112 {
113 int count;
114 uint64_t x = channel_layout;
115 for (count = 0; x; count++)
116 x &= x-1; // unset lowest set bit
117 return count;
118 }