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
28 #include "audioconvert.h"
30 static const char * const channel_names[] = {
31 [0] = "FL", /* front left */
32 [1] = "FR", /* front right */
33 [2] = "FC", /* front center */
34 [3] = "LFE", /* low frequency */
35 [4] = "BL", /* back left */
36 [5] = "BR", /* back right */
37 [6] = "FLC", /* front left-of-center */
38 [7] = "FRC", /* front right-of-center */
39 [8] = "BC", /* back-center */
40 [9] = "SL", /* side left */
41 [10] = "SR", /* side right */
42 [11] = "TC", /* top center */
43 [12] = "TFL", /* top front left */
44 [13] = "TFC", /* top front center */
45 [14] = "TFR", /* top front right */
46 [15] = "TBL", /* top back left */
47 [16] = "TBC", /* top back center */
48 [17] = "TBR", /* top back right */
49 [29] = "DL", /* downmix left */
50 [30] = "DR", /* downmix right */
53 static const char *get_channel_name(int channel_id)
55 if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
57 return channel_names[channel_id];
64 } channel_layout_map[] = {
65 { "mono", 1, AV_CH_LAYOUT_MONO },
66 { "stereo", 2, AV_CH_LAYOUT_STEREO },
67 { "4.0", 4, AV_CH_LAYOUT_4POINT0 },
68 { "quad", 4, AV_CH_LAYOUT_QUAD },
69 { "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },
70 { "5.0(side)", 5, AV_CH_LAYOUT_5POINT0 },
71 { "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },
72 { "5.1(side)", 6, AV_CH_LAYOUT_5POINT1 },
73 { "7.1", 8, AV_CH_LAYOUT_7POINT1 },
74 { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
75 { "downmix", 2, AV_CH_LAYOUT_STEREO_DOWNMIX, },
79 static uint64_t get_channel_layout_single(const char *name, int name_len)
85 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map) - 1; i++) {
86 if (strlen(channel_layout_map[i].name) == name_len &&
87 !memcmp(channel_layout_map[i].name, name, name_len))
88 return channel_layout_map[i].layout;
90 for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
91 if (channel_names[i] &&
92 strlen(channel_names[i]) == name_len &&
93 !memcmp(channel_names[i], name, name_len))
94 return (int64_t)1 << i;
95 i = strtol(name, &end, 10);
96 if (end - name == name_len ||
97 (end + 1 - name == name_len && *end == 'c'))
98 return av_get_default_channel_layout(i);
99 layout = strtoll(name, &end, 0);
100 if (end - name == name_len)
101 return FFMAX(layout, 0);
105 uint64_t av_get_channel_layout(const char *name)
108 const char *name_end = name + strlen(name);
109 int64_t layout = 0, layout_single;
111 for (n = name; n < name_end; n = e + 1) {
112 for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
113 layout_single = get_channel_layout_single(n, e - n);
116 layout |= layout_single;
121 void av_get_channel_layout_string(char *buf, int buf_size,
122 int nb_channels, uint64_t channel_layout)
126 if (nb_channels <= 0)
127 nb_channels = av_get_channel_layout_nb_channels(channel_layout);
129 for (i = 0; channel_layout_map[i].name; i++)
130 if (nb_channels == channel_layout_map[i].nb_channels &&
131 channel_layout == channel_layout_map[i].layout) {
132 av_strlcpy(buf, channel_layout_map[i].name, buf_size);
136 snprintf(buf, buf_size, "%d channels", nb_channels);
137 if (channel_layout) {
139 av_strlcat(buf, " (", buf_size);
140 for (i = 0, ch = 0; i < 64; i++) {
141 if ((channel_layout & (UINT64_C(1) << i))) {
142 const char *name = get_channel_name(i);
145 av_strlcat(buf, "+", buf_size);
146 av_strlcat(buf, name, buf_size);
151 av_strlcat(buf, ")", buf_size);
155 int av_get_channel_layout_nb_channels(uint64_t channel_layout)
158 uint64_t x = channel_layout;
159 for (count = 0; x; count++)
160 x &= x-1; // unset lowest set bit
164 int64_t av_get_default_channel_layout(int nb_channels) {
166 for (i = 0; channel_layout_map[i].name; i++)
167 if (nb_channels == channel_layout_map[i].nb_channels)
168 return channel_layout_map[i].layout;