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channel_layout.c
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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 
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 
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;
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 
109 static 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'))
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 
139 uint64_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 
155 void av_bprint_channel_layout(struct AVBPrint *bp,
156  int nb_channels, uint64_t channel_layout)
157 {
158  int i;
159 
160  if (nb_channels <= 0)
161  nb_channels = av_get_channel_layout_nb_channels(channel_layout);
162 
163  for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
164  if (nb_channels == channel_layout_map[i].nb_channels &&
165  channel_layout == channel_layout_map[i].layout) {
166  av_bprintf(bp, "%s", channel_layout_map[i].name);
167  return;
168  }
169 
170  av_bprintf(bp, "%d channels", nb_channels);
171  if (channel_layout) {
172  int i, ch;
173  av_bprintf(bp, " (");
174  for (i = 0, ch = 0; i < 64; i++) {
175  if ((channel_layout & (UINT64_C(1) << i))) {
176  const char *name = get_channel_name(i);
177  if (name) {
178  if (ch > 0)
179  av_bprintf(bp, "+");
180  av_bprintf(bp, "%s", name);
181  }
182  ch++;
183  }
184  }
185  av_bprintf(bp, ")");
186  }
187 }
188 
189 void av_get_channel_layout_string(char *buf, int buf_size,
190  int nb_channels, uint64_t channel_layout)
191 {
192  AVBPrint bp;
193 
194  av_bprint_init_for_buffer(&bp, buf, buf_size);
195  av_bprint_channel_layout(&bp, nb_channels, channel_layout);
196 }
197 
198 int av_get_channel_layout_nb_channels(uint64_t channel_layout)
199 {
200  return av_popcount64(channel_layout);
201 }
202 
204  int i;
205  for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
206  if (nb_channels == channel_layout_map[i].nb_channels)
207  return channel_layout_map[i].layout;
208  return 0;
209 }
210 
211 int av_get_channel_layout_channel_index(uint64_t channel_layout,
212  uint64_t channel)
213 {
214  if (!(channel_layout & channel) ||
215  av_get_channel_layout_nb_channels(channel) != 1)
216  return AVERROR(EINVAL);
217  channel_layout &= channel - 1;
218  return av_get_channel_layout_nb_channels(channel_layout);
219 }
220 
221 const char *av_get_channel_name(uint64_t channel)
222 {
223  int i;
224  if (av_get_channel_layout_nb_channels(channel) != 1)
225  return NULL;
226  for (i = 0; i < 64; i++)
227  if ((1ULL<<i) & channel)
228  return get_channel_name(i);
229  return NULL;
230 }
231 
232 const char *av_get_channel_description(uint64_t channel)
233 {
234  int i;
235  if (av_get_channel_layout_nb_channels(channel) != 1)
236  return NULL;
237  for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
238  if ((1ULL<<i) & channel)
239  return channel_names[i].description;
240  return NULL;
241 }
242 
243 uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
244 {
245  int i;
246 
247  if (av_get_channel_layout_nb_channels(channel_layout) <= index)
248  return 0;
249 
250  for (i = 0; i < 64; i++) {
251  if ((1ULL << i) & channel_layout && !index--)
252  return 1ULL << i;
253  }
254  return 0;
255 }
256 
258  const char **name)
259 {
260  if (index >= FF_ARRAY_ELEMS(channel_layout_map))
261  return AVERROR_EOF;
262  if (layout) *layout = channel_layout_map[index].layout;
263  if (name) *name = channel_layout_map[index].name;
264  return 0;
265 }
#define NULL
Definition: coverity.c:32
#define AV_CH_LAYOUT_7POINT1
#define AV_CH_LAYOUT_4POINT1
#define AV_CH_LAYOUT_HEXADECAGONAL
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:94
#define AV_CH_LAYOUT_6POINT1
#define AV_CH_LAYOUT_6POINT0
#define AV_CH_LAYOUT_SURROUND
static const char * get_channel_name(int channel_id)
external API header
#define AV_CH_LAYOUT_7POINT0_FRONT
#define AV_CH_LAYOUT_4POINT0
#define AV_CH_LAYOUT_7POINT0
#define AV_CH_LAYOUT_STEREO
const char * description
#define AV_CH_LAYOUT_5POINT0
int av_get_channel_layout_nb_channels(uint64_t channel_layout)
Return the number of channels in the channel layout.
int av_get_standard_channel_layout(unsigned index, uint64_t *layout, const char **name)
Get the value and name of a standard channel layout.
const char * name
uint64_t av_get_channel_layout(const char *name)
Return a channel layout id that matches name, or 0 if no match is found.
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
#define AV_CH_LAYOUT_HEXAGONAL
void av_bprint_init_for_buffer(AVBPrint *buf, char *buffer, unsigned size)
Init a print buffer using a pre-existing buffer.
Definition: bprint.c:85
#define AVERROR_EOF
End of file.
Definition: error.h:55
#define AV_CH_LAYOUT_5POINT1
static const struct channel_name channel_names[]
#define AVERROR(e)
Definition: error.h:43
#define AV_CH_LAYOUT_QUAD
#define FFMAX(a, b)
Definition: common.h:94
#define AV_CH_LAYOUT_2_1
#define AV_CH_LAYOUT_2_2
#define AV_CH_LAYOUT_6POINT0_FRONT
static const struct @207 channel_layout_map[]
audio channel layout utility functions
#define AV_CH_LAYOUT_STEREO_DOWNMIX
#define AV_CH_LAYOUT_3POINT1
int n
Definition: avisynth_c.h:547
#define AV_CH_LAYOUT_5POINT1_BACK
#define AV_CH_LAYOUT_6POINT1_BACK
#define FF_ARRAY_ELEMS(a)
void av_bprint_channel_layout(struct AVBPrint *bp, int nb_channels, uint64_t channel_layout)
Append a description of a channel layout to a bprint buffer.
void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, uint64_t channel_layout)
Return a description of a channel layout.
void * buf
Definition: avisynth_c.h:553
#define AV_CH_LAYOUT_7POINT1_WIDE_BACK
int index
Definition: gxfenc.c:89
#define AV_CH_LAYOUT_5POINT0_BACK
#define AV_CH_LAYOUT_OCTAGONAL
int av_get_channel_layout_channel_index(uint64_t channel_layout, uint64_t channel)
Get the index of a channel in channel_layout.
#define AV_CH_LAYOUT_7POINT1_WIDE
common internal and external API header
#define AV_CH_LAYOUT_2POINT1
uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
Get the channel with the given index in channel_layout.
static uint64_t get_channel_layout_single(const char *name, int name_len)
const char * av_get_channel_name(uint64_t channel)
Get the name of a given channel.
uint64_t layout
int64_t av_get_default_channel_layout(int nb_channels)
Return default channel layout for a given number of channels.
#define AV_CH_LAYOUT_6POINT1_FRONT
const char * av_get_channel_description(uint64_t channel)
Get the description of a given channel.
int nb_channels
#define AV_CH_LAYOUT_MONO
const char * name
Definition: opengl_enc.c:103