2 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
6 * FFmpeg 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.
11 * FFmpeg 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.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * audio conversion routines
26 #include "libavutil/avstring.h"
27 #include "audioconvert.h"
29 static const char * const channel_names[] = {
30 "FL", "FR", "FC", "LFE", "BL", "BR", "FLC", "FRC",
31 "BC", "SL", "SR", "TC", "TFL", "TFC", "TFR", "TBL",
37 static const char *get_channel_name(int channel_id)
39 if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
41 return channel_names[channel_id];
48 } channel_layout_map[] = {
49 { "mono", 1, AV_CH_LAYOUT_MONO },
50 { "stereo", 2, AV_CH_LAYOUT_STEREO },
51 { "4.0", 4, AV_CH_LAYOUT_4POINT0 },
52 { "quad", 4, AV_CH_LAYOUT_QUAD },
53 { "5.0", 5, AV_CH_LAYOUT_5POINT0 },
54 { "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },
55 { "5.1", 6, AV_CH_LAYOUT_5POINT1 },
56 { "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },
57 { "5.1+downmix", 8, AV_CH_LAYOUT_5POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
58 { "7.1", 8, AV_CH_LAYOUT_7POINT1 },
59 { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
60 { "7.1+downmix", 10, AV_CH_LAYOUT_7POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
64 int64_t av_get_channel_layout(const char *name)
68 if (!strcmp(channel_layout_map[i].name, name))
69 return channel_layout_map[i].layout;
71 } while (channel_layout_map[i].name);
76 void av_get_channel_layout_string(char *buf, int buf_size,
77 int nb_channels, int64_t channel_layout)
81 for (i = 0; channel_layout_map[i].name; i++)
82 if (nb_channels == channel_layout_map[i].nb_channels &&
83 channel_layout == channel_layout_map[i].layout) {
84 av_strlcpy(buf, channel_layout_map[i].name, buf_size);
88 snprintf(buf, buf_size, "%d channels", nb_channels);
91 av_strlcat(buf, " (", buf_size);
92 for(i=0,ch=0; i<64; i++) {
93 if ((channel_layout & (1L<<i))) {
94 const char *name = get_channel_name(i);
96 if (ch>0) av_strlcat(buf, "|", buf_size);
97 av_strlcat(buf, name, buf_size);
102 av_strlcat(buf, ")", buf_size);
106 int av_get_channel_layout_nb_channels(int64_t channel_layout)
109 uint64_t x = channel_layout;
110 for (count = 0; x; count++)
111 x &= x-1; // unset lowest set bit