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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", 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 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
110 static uint64_t get_channel_layout_single(const char *name, int name_len, int compat)
111 #else
112 static uint64_t get_channel_layout_single(const char *name, int name_len)
113 #endif
114 {
115  int i;
116  char *end;
117  int64_t layout;
118 
119  for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {
120  if (strlen(channel_layout_map[i].name) == name_len &&
121  !memcmp(channel_layout_map[i].name, name, name_len))
122  return channel_layout_map[i].layout;
123  }
124  for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
125  if (channel_names[i].name &&
126  strlen(channel_names[i].name) == name_len &&
127  !memcmp(channel_names[i].name, name, name_len))
128  return (int64_t)1 << i;
129  i = strtol(name, &end, 10);
130 
131 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
132  if (compat) {
133  if (end - name == name_len ||
134  (end + 1 - name == name_len && *end == 'c')) {
135  layout = av_get_default_channel_layout(i);
136  if (end - name == name_len) {
138  "Single channel layout '%.*s' is interpreted as a number of channels, "
139  "switch to the syntax '%.*sc' otherwise it will be interpreted as a "
140  "channel layout number in a later version\n",
141  name_len, name, name_len, name);
142  }
143  return layout;
144  }
145  } else {
146 #endif
147  if ((end + 1 - name == name_len && *end == 'c'))
149 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
150  }
151 #endif
152 
153  layout = strtoll(name, &end, 0);
154  if (end - name == name_len)
155  return FFMAX(layout, 0);
156  return 0;
157 }
158 
159 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
160 uint64_t ff_get_channel_layout(const char *name, int compat)
161 #else
162 uint64_t av_get_channel_layout(const char *name)
163 #endif
164 {
165  const char *n, *e;
166  const char *name_end = name + strlen(name);
167  int64_t layout = 0, layout_single;
168 
169  for (n = name; n < name_end; n = e + 1) {
170  for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
171 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
172  layout_single = get_channel_layout_single(n, e - n, compat);
173 #else
174  layout_single = get_channel_layout_single(n, e - n);
175 #endif
176  if (!layout_single)
177  return 0;
178  layout |= layout_single;
179  }
180  return layout;
181 }
182 
183 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
184 uint64_t av_get_channel_layout(const char *name)
185 {
186  return ff_get_channel_layout(name, 1);
187 }
188 #endif
189 
190 void av_bprint_channel_layout(struct AVBPrint *bp,
191  int nb_channels, uint64_t channel_layout)
192 {
193  int i;
194 
195  if (nb_channels <= 0)
196  nb_channels = av_get_channel_layout_nb_channels(channel_layout);
197 
198  for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
199  if (nb_channels == channel_layout_map[i].nb_channels &&
200  channel_layout == channel_layout_map[i].layout) {
201  av_bprintf(bp, "%s", channel_layout_map[i].name);
202  return;
203  }
204 
205  av_bprintf(bp, "%d channels", nb_channels);
206  if (channel_layout) {
207  int i, ch;
208  av_bprintf(bp, " (");
209  for (i = 0, ch = 0; i < 64; i++) {
210  if ((channel_layout & (UINT64_C(1) << i))) {
211  const char *name = get_channel_name(i);
212  if (name) {
213  if (ch > 0)
214  av_bprintf(bp, "+");
215  av_bprintf(bp, "%s", name);
216  }
217  ch++;
218  }
219  }
220  av_bprintf(bp, ")");
221  }
222 }
223 
224 void av_get_channel_layout_string(char *buf, int buf_size,
225  int nb_channels, uint64_t channel_layout)
226 {
227  AVBPrint bp;
228 
229  av_bprint_init_for_buffer(&bp, buf, buf_size);
230  av_bprint_channel_layout(&bp, nb_channels, channel_layout);
231 }
232 
233 int av_get_channel_layout_nb_channels(uint64_t channel_layout)
234 {
235  return av_popcount64(channel_layout);
236 }
237 
239  int i;
240  for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
241  if (nb_channels == channel_layout_map[i].nb_channels)
242  return channel_layout_map[i].layout;
243  return 0;
244 }
245 
246 int av_get_channel_layout_channel_index(uint64_t channel_layout,
247  uint64_t channel)
248 {
249  if (!(channel_layout & channel) ||
250  av_get_channel_layout_nb_channels(channel) != 1)
251  return AVERROR(EINVAL);
252  channel_layout &= channel - 1;
253  return av_get_channel_layout_nb_channels(channel_layout);
254 }
255 
256 const char *av_get_channel_name(uint64_t channel)
257 {
258  int i;
259  if (av_get_channel_layout_nb_channels(channel) != 1)
260  return NULL;
261  for (i = 0; i < 64; i++)
262  if ((1ULL<<i) & channel)
263  return get_channel_name(i);
264  return NULL;
265 }
266 
267 const char *av_get_channel_description(uint64_t channel)
268 {
269  int i;
270  if (av_get_channel_layout_nb_channels(channel) != 1)
271  return NULL;
272  for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
273  if ((1ULL<<i) & channel)
274  return channel_names[i].description;
275  return NULL;
276 }
277 
278 uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
279 {
280  int i;
281 
282  if (av_get_channel_layout_nb_channels(channel_layout) <= index)
283  return 0;
284 
285  for (i = 0; i < 64; i++) {
286  if ((1ULL << i) & channel_layout && !index--)
287  return 1ULL << i;
288  }
289  return 0;
290 }
291 
293  const char **name)
294 {
295  if (index >= FF_ARRAY_ELEMS(channel_layout_map))
296  return AVERROR_EOF;
297  if (layout) *layout = channel_layout_map[index].layout;
298  if (name) *name = channel_layout_map[index].name;
299  return 0;
300 }
#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_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
#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_log(a,...)
#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:79
#define AV_CH_LAYOUT_2_1
#define AV_CH_LAYOUT_2_2
#define AV_CH_LAYOUT_6POINT0_FRONT
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
static uint64_t get_channel_layout_single(const char *name, int name_len, int compat)
#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 const struct @185 channel_layout_map[]
const char * av_get_channel_name(uint64_t channel)
Get the name of a given channel.
uint64_t ff_get_channel_layout(const char *name, int compat)
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