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
34 struct channel_name {
35 const char *name;
36 const char *description;
37 };
38
39 static 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
get_channel_name(int channel_id)67 static 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
74 static 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", 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 { "downmix", 2, AV_CH_LAYOUT_STEREO_DOWNMIX, },
106 };
107
108 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
get_channel_layout_single(const char * name,int name_len,int compat)109 static uint64_t get_channel_layout_single(const char *name, int name_len, int compat)
110 #else
111 static uint64_t get_channel_layout_single(const char *name, int name_len)
112 #endif
113 {
114 int i;
115 char *end;
116 int64_t layout;
117
118 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {
119 if (strlen(channel_layout_map[i].name) == name_len &&
120 !memcmp(channel_layout_map[i].name, name, name_len))
121 return channel_layout_map[i].layout;
122 }
123 for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
124 if (channel_names[i].name &&
125 strlen(channel_names[i].name) == name_len &&
126 !memcmp(channel_names[i].name, name, name_len))
127 return (int64_t)1 << i;
128 i = strtol(name, &end, 10);
129
130 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
131 if (compat) {
132 if (end - name == name_len ||
133 (end + 1 - name == name_len && *end == 'c')) {
134 layout = av_get_default_channel_layout(i);
135 if (end - name == name_len) {
136 av_log(NULL, AV_LOG_WARNING,
137 "Single channel layout '%.*s' is interpreted as a number of channels, "
138 "switch to the syntax '%.*sc' otherwise it will be interpreted as a "
139 "channel layout number in a later version\n",
140 name_len, name, name_len, name);
141 return layout;
142 }
143 }
144 } else {
145 #endif
146 if ((end + 1 - name == name_len && *end == 'c'))
147 return av_get_default_channel_layout(i);
148 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
149 }
150 #endif
151
152 layout = strtoll(name, &end, 0);
153 if (end - name == name_len)
154 return FFMAX(layout, 0);
155 return 0;
156 }
157
158 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
ff_get_channel_layout(const char * name,int compat)159 uint64_t ff_get_channel_layout(const char *name, int compat)
160 #else
161 uint64_t av_get_channel_layout(const char *name)
162 #endif
163 {
164 const char *n, *e;
165 const char *name_end = name + strlen(name);
166 int64_t layout = 0, layout_single;
167
168 for (n = name; n < name_end; n = e + 1) {
169 for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
170 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
171 layout_single = get_channel_layout_single(n, e - n, compat);
172 #else
173 layout_single = get_channel_layout_single(n, e - n);
174 #endif
175 if (!layout_single)
176 return 0;
177 layout |= layout_single;
178 }
179 return layout;
180 }
181
182 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
av_get_channel_layout(const char * name)183 uint64_t av_get_channel_layout(const char *name)
184 {
185 return ff_get_channel_layout(name, 1);
186 }
187 #endif
188
av_bprint_channel_layout(struct AVBPrint * bp,int nb_channels,uint64_t channel_layout)189 void av_bprint_channel_layout(struct AVBPrint *bp,
190 int nb_channels, uint64_t channel_layout)
191 {
192 int i;
193
194 if (nb_channels <= 0)
195 nb_channels = av_get_channel_layout_nb_channels(channel_layout);
196
197 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
198 if (nb_channels == channel_layout_map[i].nb_channels &&
199 channel_layout == channel_layout_map[i].layout) {
200 av_bprintf(bp, "%s", channel_layout_map[i].name);
201 return;
202 }
203
204 av_bprintf(bp, "%d channels", nb_channels);
205 if (channel_layout) {
206 int i, ch;
207 av_bprintf(bp, " (");
208 for (i = 0, ch = 0; i < 64; i++) {
209 if ((channel_layout & (UINT64_C(1) << i))) {
210 const char *name = get_channel_name(i);
211 if (name) {
212 if (ch > 0)
213 av_bprintf(bp, "+");
214 av_bprintf(bp, "%s", name);
215 }
216 ch++;
217 }
218 }
219 av_bprintf(bp, ")");
220 }
221 }
222
av_get_channel_layout_string(char * buf,int buf_size,int nb_channels,uint64_t channel_layout)223 void av_get_channel_layout_string(char *buf, int buf_size,
224 int nb_channels, uint64_t channel_layout)
225 {
226 AVBPrint bp;
227
228 av_bprint_init_for_buffer(&bp, buf, buf_size);
229 av_bprint_channel_layout(&bp, nb_channels, channel_layout);
230 }
231
av_get_channel_layout_nb_channels(uint64_t channel_layout)232 int av_get_channel_layout_nb_channels(uint64_t channel_layout)
233 {
234 return av_popcount64(channel_layout);
235 }
236
av_get_default_channel_layout(int nb_channels)237 int64_t av_get_default_channel_layout(int nb_channels) {
238 int i;
239 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
240 if (nb_channels == channel_layout_map[i].nb_channels)
241 return channel_layout_map[i].layout;
242 return 0;
243 }
244
av_get_channel_layout_channel_index(uint64_t channel_layout,uint64_t channel)245 int av_get_channel_layout_channel_index(uint64_t channel_layout,
246 uint64_t channel)
247 {
248 if (!(channel_layout & channel) ||
249 av_get_channel_layout_nb_channels(channel) != 1)
250 return AVERROR(EINVAL);
251 channel_layout &= channel - 1;
252 return av_get_channel_layout_nb_channels(channel_layout);
253 }
254
av_get_channel_name(uint64_t channel)255 const char *av_get_channel_name(uint64_t channel)
256 {
257 int i;
258 if (av_get_channel_layout_nb_channels(channel) != 1)
259 return NULL;
260 for (i = 0; i < 64; i++)
261 if ((ULLN(1)<<i) & channel)
262 return get_channel_name(i);
263 return NULL;
264 }
265
av_get_channel_description(uint64_t channel)266 const char *av_get_channel_description(uint64_t channel)
267 {
268 int i;
269 if (av_get_channel_layout_nb_channels(channel) != 1)
270 return NULL;
271 for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
272 if ((ULLN(1)<<i) & channel)
273 return channel_names[i].description;
274 return NULL;
275 }
276
av_channel_layout_extract_channel(uint64_t channel_layout,int index)277 uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
278 {
279 int i;
280
281 if (av_get_channel_layout_nb_channels(channel_layout) <= index)
282 return 0;
283
284 for (i = 0; i < 64; i++) {
285 if ((ULLN(1) << i) & channel_layout && !index--)
286 return ULLN(1) << i;
287 }
288 return 0;
289 }
290
av_get_standard_channel_layout(unsigned index,uint64_t * layout,const char ** name)291 int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
292 const char **name)
293 {
294 if (index >= FF_ARRAY_ELEMS(channel_layout_map))
295 return AVERROR_EOF;
296 if (layout) *layout = channel_layout_map[index].layout;
297 if (name) *name = channel_layout_map[index].name;
298 return 0;
299 }
300