2 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of Libav.
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.
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.
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
23 * audio channel layout utility functions
30 #include "channel_layout.h"
33 static const char * const channel_names[] = {
34 [0] = "FL", /* front left */
35 [1] = "FR", /* front right */
36 [2] = "FC", /* front center */
37 [3] = "LFE", /* low frequency */
38 [4] = "BL", /* back left */
39 [5] = "BR", /* back right */
40 [6] = "FLC", /* front left-of-center */
41 [7] = "FRC", /* front right-of-center */
42 [8] = "BC", /* back-center */
43 [9] = "SL", /* side left */
44 [10] = "SR", /* side right */
45 [11] = "TC", /* top center */
46 [12] = "TFL", /* top front left */
47 [13] = "TFC", /* top front center */
48 [14] = "TFR", /* top front right */
49 [15] = "TBL", /* top back left */
50 [16] = "TBC", /* top back center */
51 [17] = "TBR", /* top back right */
52 [29] = "DL", /* downmix left */
53 [30] = "DR", /* downmix right */
54 [31] = "WL", /* wide left */
55 [32] = "WR", /* wide right */
56 [33] = "SDL", /* surround direct left */
57 [34] = "SDR", /* surround direct right */
58 [35] = "LFE2", /* low frequency 2 */
61 static const char *get_channel_name(int channel_id)
63 if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
65 return channel_names[channel_id];
72 } channel_layout_map[] = {
73 { "mono", 1, AV_CH_LAYOUT_MONO },
74 { "stereo", 2, AV_CH_LAYOUT_STEREO },
75 { "stereo", 2, AV_CH_LAYOUT_STEREO_DOWNMIX },
76 { "2.1", 3, AV_CH_LAYOUT_2POINT1 },
77 { "3.0", 3, AV_CH_LAYOUT_SURROUND },
78 { "3.0(back)", 3, AV_CH_LAYOUT_2_1 },
79 { "3.1", 4, AV_CH_LAYOUT_3POINT1 },
80 { "4.0", 4, AV_CH_LAYOUT_4POINT0 },
81 { "quad", 4, AV_CH_LAYOUT_QUAD },
82 { "quad(side)", 4, AV_CH_LAYOUT_2_2 },
83 { "4.1", 5, AV_CH_LAYOUT_4POINT1 },
84 { "5.0", 5, AV_CH_LAYOUT_5POINT0 },
85 { "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },
86 { "5.1", 6, AV_CH_LAYOUT_5POINT1 },
87 { "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },
88 { "6.0", 6, AV_CH_LAYOUT_6POINT0 },
89 { "6.0(front)", 6, AV_CH_LAYOUT_6POINT0_FRONT },
90 { "hexagonal", 6, AV_CH_LAYOUT_HEXAGONAL },
91 { "6.1", 7, AV_CH_LAYOUT_6POINT1 },
92 { "6.1", 7, AV_CH_LAYOUT_6POINT1_BACK },
93 { "6.1(front)", 7, AV_CH_LAYOUT_6POINT1_FRONT },
94 { "7.0", 7, AV_CH_LAYOUT_7POINT0 },
95 { "7.0(front)", 7, AV_CH_LAYOUT_7POINT0_FRONT },
96 { "7.1", 8, AV_CH_LAYOUT_7POINT1 },
97 { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
98 { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE_BACK },
99 { "octagonal", 8, AV_CH_LAYOUT_OCTAGONAL },
100 { "downmix", 2, AV_CH_LAYOUT_STEREO_DOWNMIX, },
104 static uint64_t get_channel_layout_single(const char *name, int name_len)
110 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map) - 1; i++) {
111 if (strlen(channel_layout_map[i].name) == name_len &&
112 !memcmp(channel_layout_map[i].name, name, name_len))
113 return channel_layout_map[i].layout;
115 for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
116 if (channel_names[i] &&
117 strlen(channel_names[i]) == name_len &&
118 !memcmp(channel_names[i], name, name_len))
119 return (int64_t)1 << i;
120 i = strtol(name, &end, 10);
121 if (end - name == name_len ||
122 (end + 1 - name == name_len && *end == 'c'))
123 return av_get_default_channel_layout(i);
124 layout = strtoll(name, &end, 0);
125 if (end - name == name_len)
126 return FFMAX(layout, 0);
130 uint64_t av_get_channel_layout(const char *name)
133 const char *name_end = name + strlen(name);
134 int64_t layout = 0, layout_single;
136 for (n = name; n < name_end; n = e + 1) {
137 for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
138 layout_single = get_channel_layout_single(n, e - n);
141 layout |= layout_single;
146 void av_get_channel_layout_string(char *buf, int buf_size,
147 int nb_channels, uint64_t channel_layout)
151 if (nb_channels <= 0)
152 nb_channels = av_get_channel_layout_nb_channels(channel_layout);
154 for (i = 0; channel_layout_map[i].name; i++)
155 if (nb_channels == channel_layout_map[i].nb_channels &&
156 channel_layout == channel_layout_map[i].layout) {
157 av_strlcpy(buf, channel_layout_map[i].name, buf_size);
161 snprintf(buf, buf_size, "%d channels", nb_channels);
162 if (channel_layout) {
164 av_strlcat(buf, " (", buf_size);
165 for (i = 0, ch = 0; i < 64; i++) {
166 if ((channel_layout & (UINT64_C(1) << i))) {
167 const char *name = get_channel_name(i);
170 av_strlcat(buf, "|", buf_size);
171 av_strlcat(buf, name, buf_size);
176 av_strlcat(buf, ")", buf_size);
180 int av_get_channel_layout_nb_channels(uint64_t channel_layout)
182 return av_popcount64(channel_layout);
185 uint64_t av_get_default_channel_layout(int nb_channels)
187 switch(nb_channels) {
188 case 1: return AV_CH_LAYOUT_MONO;
189 case 2: return AV_CH_LAYOUT_STEREO;
190 case 3: return AV_CH_LAYOUT_SURROUND;
191 case 4: return AV_CH_LAYOUT_QUAD;
192 case 5: return AV_CH_LAYOUT_5POINT0;
193 case 6: return AV_CH_LAYOUT_5POINT1;
194 case 7: return AV_CH_LAYOUT_6POINT1;
195 case 8: return AV_CH_LAYOUT_7POINT1;
200 int av_get_channel_layout_channel_index(uint64_t channel_layout,
203 if (!(channel_layout & channel) ||
204 av_get_channel_layout_nb_channels(channel) != 1)
205 return AVERROR(EINVAL);
206 channel_layout &= channel - 1;
207 return av_get_channel_layout_nb_channels(channel_layout);
210 const char *av_get_channel_name(uint64_t channel)
213 if (av_get_channel_layout_nb_channels(channel) != 1)
215 for (i = 0; i < 64; i++)
216 if ((1ULL<<i) & channel)
217 return get_channel_name(i);
221 uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
225 if (av_get_channel_layout_nb_channels(channel_layout) <= index)
228 for (i = 0; i < 64; i++) {
229 if ((1ULL << i) & channel_layout && !index--)