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 channel layout utility functions
28 #include "channel_layout.h"
34 const char *description;
37 static const struct channel_name channel_names[] = {
38 [0] = { "FL", "front left" },
39 [1] = { "FR", "front right" },
40 [2] = { "FC", "front center" },
41 [3] = { "LFE", "low frequency" },
42 [4] = { "BL", "back left" },
43 [5] = { "BR", "back right" },
44 [6] = { "FLC", "front left-of-center" },
45 [7] = { "FRC", "front right-of-center" },
46 [8] = { "BC", "back center" },
47 [9] = { "SL", "side left" },
48 [10] = { "SR", "side right" },
49 [11] = { "TC", "top center" },
50 [12] = { "TFL", "top front left" },
51 [13] = { "TFC", "top front center" },
52 [14] = { "TFR", "top front right" },
53 [15] = { "TBL", "top back left" },
54 [16] = { "TBC", "top back center" },
55 [17] = { "TBR", "top back right" },
56 [29] = { "DL", "downmix left" },
57 [30] = { "DR", "downmix right" },
58 [31] = { "WL", "wide left" },
59 [32] = { "WR", "wide right" },
60 [33] = { "SDL", "surround direct left" },
61 [34] = { "SDR", "surround direct right" },
62 [35] = { "LFE2", "low frequency 2" },
65 static const char *get_channel_name(int channel_id)
67 if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
69 return channel_names[channel_id].name;
76 } channel_layout_map[] = {
77 { "mono", 1, AV_CH_LAYOUT_MONO },
78 { "stereo", 2, AV_CH_LAYOUT_STEREO },
79 { "2.1", 3, AV_CH_LAYOUT_2POINT1 },
80 { "3.0", 3, AV_CH_LAYOUT_SURROUND },
81 { "3.0(back)", 3, AV_CH_LAYOUT_2_1 },
82 { "4.0", 4, AV_CH_LAYOUT_4POINT0 },
83 { "quad", 4, AV_CH_LAYOUT_QUAD },
84 { "quad(side)", 4, AV_CH_LAYOUT_2_2 },
85 { "3.1", 4, AV_CH_LAYOUT_3POINT1 },
86 { "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },
87 { "5.0(side)", 5, AV_CH_LAYOUT_5POINT0 },
88 { "4.1", 5, AV_CH_LAYOUT_4POINT1 },
89 { "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },
90 { "5.1(side)", 6, AV_CH_LAYOUT_5POINT1 },
91 { "6.0", 6, AV_CH_LAYOUT_6POINT0 },
92 { "6.0(front)", 6, AV_CH_LAYOUT_6POINT0_FRONT },
93 { "hexagonal", 6, AV_CH_LAYOUT_HEXAGONAL },
94 { "6.1", 7, AV_CH_LAYOUT_6POINT1 },
95 { "6.1", 7, AV_CH_LAYOUT_6POINT1_BACK },
96 { "6.1(front)", 7, AV_CH_LAYOUT_6POINT1_FRONT },
97 { "7.0", 7, AV_CH_LAYOUT_7POINT0 },
98 { "7.0(front)", 7, AV_CH_LAYOUT_7POINT0_FRONT },
99 { "7.1", 8, AV_CH_LAYOUT_7POINT1 },
100 { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
101 { "octagonal", 8, AV_CH_LAYOUT_OCTAGONAL },
102 { "downmix", 2, AV_CH_LAYOUT_STEREO_DOWNMIX, },
105 static uint64_t get_channel_layout_single(const char *name, int name_len)
111 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {
112 if (strlen(channel_layout_map[i].name) == name_len &&
113 !memcmp(channel_layout_map[i].name, name, name_len))
114 return channel_layout_map[i].layout;
116 for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
117 if (channel_names[i].name &&
118 strlen(channel_names[i].name) == name_len &&
119 !memcmp(channel_names[i].name, name, name_len))
120 return (int64_t)1 << i;
121 i = strtol(name, &end, 10);
122 if (end - name == name_len ||
123 (end + 1 - name == name_len && *end == 'c'))
124 return av_get_default_channel_layout(i);
125 layout = strtoll(name, &end, 0);
126 if (end - name == name_len)
127 return FFMAX(layout, 0);
131 uint64_t av_get_channel_layout(const char *name)
134 const char *name_end = name + strlen(name);
135 int64_t layout = 0, layout_single;
137 for (n = name; n < name_end; n = e + 1) {
138 for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
139 layout_single = get_channel_layout_single(n, e - n);
142 layout |= layout_single;
147 void av_bprint_channel_layout(struct AVBPrint *bp,
148 int nb_channels, uint64_t channel_layout)
152 if (nb_channels <= 0)
153 nb_channels = av_get_channel_layout_nb_channels(channel_layout);
155 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
156 if (nb_channels == channel_layout_map[i].nb_channels &&
157 channel_layout == channel_layout_map[i].layout) {
158 av_bprintf(bp, "%s", channel_layout_map[i].name);
162 av_bprintf(bp, "%d channels", nb_channels);
163 if (channel_layout) {
165 av_bprintf(bp, " (");
166 for (i = 0, ch = 0; i < 64; i++) {
167 if ((channel_layout & (UINT64_C(1) << i))) {
168 const char *name = get_channel_name(i);
172 av_bprintf(bp, "%s", name);
181 void av_get_channel_layout_string(char *buf, int buf_size,
182 int nb_channels, uint64_t channel_layout)
186 av_bprint_init_for_buffer(&bp, buf, buf_size);
187 av_bprint_channel_layout(&bp, nb_channels, channel_layout);
190 int av_get_channel_layout_nb_channels(uint64_t channel_layout)
192 return av_popcount64(channel_layout);
195 int64_t av_get_default_channel_layout(int nb_channels) {
197 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
198 if (nb_channels == channel_layout_map[i].nb_channels)
199 return channel_layout_map[i].layout;
203 int av_get_channel_layout_channel_index(uint64_t channel_layout,
206 if (!(channel_layout & channel) ||
207 av_get_channel_layout_nb_channels(channel) != 1)
208 return AVERROR(EINVAL);
209 channel_layout &= channel - 1;
210 return av_get_channel_layout_nb_channels(channel_layout);
213 const char *av_get_channel_name(uint64_t channel)
216 if (av_get_channel_layout_nb_channels(channel) != 1)
218 for (i = 0; i < 64; i++)
219 if ((1ULL<<i) & channel)
220 return get_channel_name(i);
224 const char *av_get_channel_description(uint64_t channel)
227 if (av_get_channel_layout_nb_channels(channel) != 1)
229 for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
230 if ((1ULL<<i) & channel)
231 return channel_names[i].description;
235 uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
239 if (av_get_channel_layout_nb_channels(channel_layout) <= index)
242 for (i = 0; i < 64; i++) {
243 if ((1ULL << i) & channel_layout && !index--)
249 int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
252 if (index >= FF_ARRAY_ELEMS(channel_layout_map))
254 if (layout) *layout = channel_layout_map[index].layout;
255 if (name) *name = channel_layout_map[index].name;