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path: root/libavutil/channel_layout.c (plain)
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1/*
2 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of FFmpeg.
5 *
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.
10 *
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.
15 *
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
19 */
20
21/**
22 * @file
23 * audio channel layout utility functions
24 */
25
26#include <stdint.h>
27
28#include "avstring.h"
29#include "avutil.h"
30#include "channel_layout.h"
31#include "bprint.h"
32#include "common.h"
33
34struct channel_name {
35 const char *name;
36 const char *description;
37};
38
39static const struct channel_name channel_names[] = {
40 [0] = { "FL", "front left" },
41 [1] = { "FR", "front right" },
42 [2] = { "FC", "front center" },
43 [3] = { "LFE", "low frequency" },
44 [4] = { "BL", "back left" },
45 [5] = { "BR", "back right" },
46 [6] = { "FLC", "front left-of-center" },
47 [7] = { "FRC", "front right-of-center" },
48 [8] = { "BC", "back center" },
49 [9] = { "SL", "side left" },
50 [10] = { "SR", "side right" },
51 [11] = { "TC", "top center" },
52 [12] = { "TFL", "top front left" },
53 [13] = { "TFC", "top front center" },
54 [14] = { "TFR", "top front right" },
55 [15] = { "TBL", "top back left" },
56 [16] = { "TBC", "top back center" },
57 [17] = { "TBR", "top back right" },
58 [29] = { "DL", "downmix left" },
59 [30] = { "DR", "downmix right" },
60 [31] = { "WL", "wide left" },
61 [32] = { "WR", "wide right" },
62 [33] = { "SDL", "surround direct left" },
63 [34] = { "SDR", "surround direct right" },
64 [35] = { "LFE2", "low frequency 2" },
65};
66
67static const char *get_channel_name(int channel_id)
68{
69 if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
70 return NULL;
71 return channel_names[channel_id].name;
72}
73
74static const struct {
75 const char *name;
76 int nb_channels;
77 uint64_t layout;
78} channel_layout_map[] = {
79 { "mono", 1, AV_CH_LAYOUT_MONO },
80 { "stereo", 2, AV_CH_LAYOUT_STEREO },
81 { "2.1", 3, AV_CH_LAYOUT_2POINT1 },
82 { "3.0", 3, AV_CH_LAYOUT_SURROUND },
83 { "3.0(back)", 3, AV_CH_LAYOUT_2_1 },
84 { "4.0", 4, AV_CH_LAYOUT_4POINT0 },
85 { "quad", 4, AV_CH_LAYOUT_QUAD },
86 { "quad(side)", 4, AV_CH_LAYOUT_2_2 },
87 { "3.1", 4, AV_CH_LAYOUT_3POINT1 },
88 { "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },
89 { "5.0(side)", 5, AV_CH_LAYOUT_5POINT0 },
90 { "4.1", 5, AV_CH_LAYOUT_4POINT1 },
91 { "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },
92 { "5.1(side)", 6, AV_CH_LAYOUT_5POINT1 },
93 { "6.0", 6, AV_CH_LAYOUT_6POINT0 },
94 { "6.0(front)", 6, AV_CH_LAYOUT_6POINT0_FRONT },
95 { "hexagonal", 6, AV_CH_LAYOUT_HEXAGONAL },
96 { "6.1", 7, AV_CH_LAYOUT_6POINT1 },
97 { "6.1(back)", 7, AV_CH_LAYOUT_6POINT1_BACK },
98 { "6.1(front)", 7, AV_CH_LAYOUT_6POINT1_FRONT },
99 { "7.0", 7, AV_CH_LAYOUT_7POINT0 },
100 { "7.0(front)", 7, AV_CH_LAYOUT_7POINT0_FRONT },
101 { "7.1", 8, AV_CH_LAYOUT_7POINT1 },
102 { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE_BACK },
103 { "7.1(wide-side)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
104 { "octagonal", 8, AV_CH_LAYOUT_OCTAGONAL },
105 { "hexadecagonal", 16, AV_CH_LAYOUT_HEXADECAGONAL },
106 { "downmix", 2, AV_CH_LAYOUT_STEREO_DOWNMIX, },
107};
108
109static uint64_t get_channel_layout_single(const char *name, int name_len)
110{
111 int i;
112 char *end;
113 int64_t layout;
114
115 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {
116 if (strlen(channel_layout_map[i].name) == name_len &&
117 !memcmp(channel_layout_map[i].name, name, name_len))
118 return channel_layout_map[i].layout;
119 }
120 for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
121 if (channel_names[i].name &&
122 strlen(channel_names[i].name) == name_len &&
123 !memcmp(channel_names[i].name, name, name_len))
124 return (int64_t)1 << i;
125
126 errno = 0;
127 i = strtol(name, &end, 10);
128
129 if (!errno && (end + 1 - name == name_len && *end == 'c'))
130 return av_get_default_channel_layout(i);
131
132 errno = 0;
133 layout = strtoll(name, &end, 0);
134 if (!errno && end - name == name_len)
135 return FFMAX(layout, 0);
136 return 0;
137}
138
139uint64_t av_get_channel_layout(const char *name)
140{
141 const char *n, *e;
142 const char *name_end = name + strlen(name);
143 int64_t layout = 0, layout_single;
144
145 for (n = name; n < name_end; n = e + 1) {
146 for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
147 layout_single = get_channel_layout_single(n, e - n);
148 if (!layout_single)
149 return 0;
150 layout |= layout_single;
151 }
152 return layout;
153}
154
155int av_get_extended_channel_layout(const char *name, uint64_t* channel_layout, int* nb_channels)
156{
157 int nb = 0;
158 char *end;
159 uint64_t layout = av_get_channel_layout(name);
160
161 if (layout) {
162 *channel_layout = layout;
163 *nb_channels = av_get_channel_layout_nb_channels(layout);
164 return 0;
165 }
166
167 nb = strtol(name, &end, 10);
168 if (!errno && *end == 'C' && *(end + 1) == '\0' && nb > 0 && nb < 64) {
169 *channel_layout = 0;
170 *nb_channels = nb;
171 return 0;
172 }
173
174 return AVERROR(EINVAL);
175}
176
177void av_bprint_channel_layout(struct AVBPrint *bp,
178 int nb_channels, uint64_t channel_layout)
179{
180 int i;
181
182 if (nb_channels <= 0)
183 nb_channels = av_get_channel_layout_nb_channels(channel_layout);
184
185 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
186 if (nb_channels == channel_layout_map[i].nb_channels &&
187 channel_layout == channel_layout_map[i].layout) {
188 av_bprintf(bp, "%s", channel_layout_map[i].name);
189 return;
190 }
191
192 av_bprintf(bp, "%d channels", nb_channels);
193 if (channel_layout) {
194 int i, ch;
195 av_bprintf(bp, " (");
196 for (i = 0, ch = 0; i < 64; i++) {
197 if ((channel_layout & (UINT64_C(1) << i))) {
198 const char *name = get_channel_name(i);
199 if (name) {
200 if (ch > 0)
201 av_bprintf(bp, "+");
202 av_bprintf(bp, "%s", name);
203 }
204 ch++;
205 }
206 }
207 av_bprintf(bp, ")");
208 }
209}
210
211void av_get_channel_layout_string(char *buf, int buf_size,
212 int nb_channels, uint64_t channel_layout)
213{
214 AVBPrint bp;
215
216 av_bprint_init_for_buffer(&bp, buf, buf_size);
217 av_bprint_channel_layout(&bp, nb_channels, channel_layout);
218}
219
220int av_get_channel_layout_nb_channels(uint64_t channel_layout)
221{
222 return av_popcount64(channel_layout);
223}
224
225int64_t av_get_default_channel_layout(int nb_channels) {
226 int i;
227 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
228 if (nb_channels == channel_layout_map[i].nb_channels)
229 return channel_layout_map[i].layout;
230 return 0;
231}
232
233int av_get_channel_layout_channel_index(uint64_t channel_layout,
234 uint64_t channel)
235{
236 if (!(channel_layout & channel) ||
237 av_get_channel_layout_nb_channels(channel) != 1)
238 return AVERROR(EINVAL);
239 channel_layout &= channel - 1;
240 return av_get_channel_layout_nb_channels(channel_layout);
241}
242
243const char *av_get_channel_name(uint64_t channel)
244{
245 int i;
246 if (av_get_channel_layout_nb_channels(channel) != 1)
247 return NULL;
248 for (i = 0; i < 64; i++)
249 if ((1ULL<<i) & channel)
250 return get_channel_name(i);
251 return NULL;
252}
253
254const char *av_get_channel_description(uint64_t channel)
255{
256 int i;
257 if (av_get_channel_layout_nb_channels(channel) != 1)
258 return NULL;
259 for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
260 if ((1ULL<<i) & channel)
261 return channel_names[i].description;
262 return NULL;
263}
264
265uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
266{
267 int i;
268
269 if (av_get_channel_layout_nb_channels(channel_layout) <= index)
270 return 0;
271
272 for (i = 0; i < 64; i++) {
273 if ((1ULL << i) & channel_layout && !index--)
274 return 1ULL << i;
275 }
276 return 0;
277}
278
279int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
280 const char **name)
281{
282 if (index >= FF_ARRAY_ELEMS(channel_layout_map))
283 return AVERROR_EOF;
284 if (layout) *layout = channel_layout_map[index].layout;
285 if (name) *name = channel_layout_map[index].name;
286 return 0;
287}
288
generated by cgit at 2024-05-17 20:22:17 (GMT)