Libav
channel_layout.c
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1 /*
2  * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of Libav.
5  *
6  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
26 #include <stdint.h>
27 
28 #include "avstring.h"
29 #include "avutil.h"
30 #include "channel_layout.h"
31 #include "common.h"
32 
33 static const char * const channel_names[] = {
34  [0] = "FL", /* front left */
35  [1] = "FR", /* front right */
36  [2] = "FC", /* front center */
37  [3] = "LFE", /* low frequency */
38  [4] = "BL", /* back left */
39  [5] = "BR", /* back right */
40  [6] = "FLC", /* front left-of-center */
41  [7] = "FRC", /* front right-of-center */
42  [8] = "BC", /* back-center */
43  [9] = "SL", /* side left */
44  [10] = "SR", /* side right */
45  [11] = "TC", /* top center */
46  [12] = "TFL", /* top front left */
47  [13] = "TFC", /* top front center */
48  [14] = "TFR", /* top front right */
49  [15] = "TBL", /* top back left */
50  [16] = "TBC", /* top back center */
51  [17] = "TBR", /* top back right */
52  [29] = "DL", /* downmix left */
53  [30] = "DR", /* downmix right */
54  [31] = "WL", /* wide left */
55  [32] = "WR", /* wide right */
56  [33] = "SDL", /* surround direct left */
57  [34] = "SDR", /* surround direct right */
58  [35] = "LFE2", /* low frequency 2 */
59 };
60 
61 static const char *get_channel_name(int channel_id)
62 {
63  if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
64  return NULL;
65  return channel_names[channel_id];
66 }
67 
68 static const struct {
69  const char *name;
71  uint64_t layout;
72 } channel_layout_map[] = {
73  { "mono", 1, AV_CH_LAYOUT_MONO },
74  { "stereo", 2, AV_CH_LAYOUT_STEREO },
75  { "stereo", 2, AV_CH_LAYOUT_STEREO_DOWNMIX },
76  { "2.1", 3, AV_CH_LAYOUT_2POINT1 },
77  { "3.0", 3, AV_CH_LAYOUT_SURROUND },
78  { "3.0(back)", 3, AV_CH_LAYOUT_2_1 },
79  { "3.1", 4, AV_CH_LAYOUT_3POINT1 },
80  { "4.0", 4, AV_CH_LAYOUT_4POINT0 },
81  { "quad", 4, AV_CH_LAYOUT_QUAD },
82  { "quad(side)", 4, AV_CH_LAYOUT_2_2 },
83  { "4.1", 5, AV_CH_LAYOUT_4POINT1 },
84  { "5.0", 5, AV_CH_LAYOUT_5POINT0 },
85  { "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },
86  { "5.1", 6, AV_CH_LAYOUT_5POINT1 },
87  { "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },
88  { "6.0", 6, AV_CH_LAYOUT_6POINT0 },
89  { "6.0(front)", 6, AV_CH_LAYOUT_6POINT0_FRONT },
90  { "hexagonal", 6, AV_CH_LAYOUT_HEXAGONAL },
91  { "6.1", 7, AV_CH_LAYOUT_6POINT1 },
92  { "6.1", 7, AV_CH_LAYOUT_6POINT1_BACK },
93  { "6.1(front)", 7, AV_CH_LAYOUT_6POINT1_FRONT },
94  { "7.0", 7, AV_CH_LAYOUT_7POINT0 },
95  { "7.0(front)", 7, AV_CH_LAYOUT_7POINT0_FRONT },
96  { "7.1", 8, AV_CH_LAYOUT_7POINT1 },
97  { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
98  { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE_BACK },
99  { "octagonal", 8, AV_CH_LAYOUT_OCTAGONAL },
100  { "downmix", 2, AV_CH_LAYOUT_STEREO_DOWNMIX, },
101  { 0 }
102 };
103 
104 static uint64_t get_channel_layout_single(const char *name, int name_len)
105 {
106  int i;
107  char *end;
108  int64_t layout;
109 
110  for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map) - 1; i++) {
111  if (strlen(channel_layout_map[i].name) == name_len &&
112  !memcmp(channel_layout_map[i].name, name, name_len))
113  return channel_layout_map[i].layout;
114  }
115  for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
116  if (channel_names[i] &&
117  strlen(channel_names[i]) == name_len &&
118  !memcmp(channel_names[i], name, name_len))
119  return (int64_t)1 << i;
120  i = strtol(name, &end, 10);
121  if (end - name == name_len ||
122  (end + 1 - name == name_len && *end == 'c'))
124  layout = strtoll(name, &end, 0);
125  if (end - name == name_len)
126  return FFMAX(layout, 0);
127  return 0;
128 }
129 
130 uint64_t av_get_channel_layout(const char *name)
131 {
132  const char *n, *e;
133  const char *name_end = name + strlen(name);
134  int64_t layout = 0, layout_single;
135 
136  for (n = name; n < name_end; n = e + 1) {
137  for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
138  layout_single = get_channel_layout_single(n, e - n);
139  if (!layout_single)
140  return 0;
141  layout |= layout_single;
142  }
143  return layout;
144 }
145 
146 void av_get_channel_layout_string(char *buf, int buf_size,
147  int nb_channels, uint64_t channel_layout)
148 {
149  int i;
150 
151  if (nb_channels <= 0)
152  nb_channels = av_get_channel_layout_nb_channels(channel_layout);
153 
154  for (i = 0; channel_layout_map[i].name; i++)
155  if (nb_channels == channel_layout_map[i].nb_channels &&
156  channel_layout == channel_layout_map[i].layout) {
157  av_strlcpy(buf, channel_layout_map[i].name, buf_size);
158  return;
159  }
160 
161  snprintf(buf, buf_size, "%d channels", nb_channels);
162  if (channel_layout) {
163  int i, ch;
164  av_strlcat(buf, " (", buf_size);
165  for (i = 0, ch = 0; i < 64; i++) {
166  if ((channel_layout & (UINT64_C(1) << i))) {
167  const char *name = get_channel_name(i);
168  if (name) {
169  if (ch > 0)
170  av_strlcat(buf, "|", buf_size);
171  av_strlcat(buf, name, buf_size);
172  }
173  ch++;
174  }
175  }
176  av_strlcat(buf, ")", buf_size);
177  }
178 }
179 
180 int av_get_channel_layout_nb_channels(uint64_t channel_layout)
181 {
182  return av_popcount64(channel_layout);
183 }
184 
186 {
187  switch(nb_channels) {
188  case 1: return AV_CH_LAYOUT_MONO;
189  case 2: return AV_CH_LAYOUT_STEREO;
190  case 3: return AV_CH_LAYOUT_SURROUND;
191  case 4: return AV_CH_LAYOUT_QUAD;
192  case 5: return AV_CH_LAYOUT_5POINT0;
193  case 6: return AV_CH_LAYOUT_5POINT1;
194  case 7: return AV_CH_LAYOUT_6POINT1;
195  case 8: return AV_CH_LAYOUT_7POINT1;
196  default: return 0;
197  }
198 }
199 
200 int av_get_channel_layout_channel_index(uint64_t channel_layout,
201  uint64_t channel)
202 {
203  if (!(channel_layout & channel) ||
204  av_get_channel_layout_nb_channels(channel) != 1)
205  return AVERROR(EINVAL);
206  channel_layout &= channel - 1;
207  return av_get_channel_layout_nb_channels(channel_layout);
208 }
209 
210 const char *av_get_channel_name(uint64_t channel)
211 {
212  int i;
213  if (av_get_channel_layout_nb_channels(channel) != 1)
214  return NULL;
215  for (i = 0; i < 64; i++)
216  if ((1ULL<<i) & channel)
217  return get_channel_name(i);
218  return NULL;
219 }
220 
221 uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
222 {
223  int i;
224 
225  if (av_get_channel_layout_nb_channels(channel_layout) <= index)
226  return 0;
227 
228  for (i = 0; i < 64; i++) {
229  if ((1ULL << i) & channel_layout && !index--)
230  return 1ULL << i;
231  }
232  return 0;
233 }
uint64_t av_get_default_channel_layout(int nb_channels)
Return default channel layout for a given number of channels.
#define AV_CH_LAYOUT_7POINT1
#define AV_CH_LAYOUT_4POINT1
#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 FF_ARRAY_ELEMS(a)
#define AV_CH_LAYOUT_STEREO
#define AV_CH_LAYOUT_5POINT0
uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
Get the channel with the given index in channel_layout.
#define AV_CH_LAYOUT_HEXAGONAL
const char * name
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_5POINT1
#define AVERROR(e)
Definition: error.h:43
int av_get_channel_layout_nb_channels(uint64_t channel_layout)
Return the number of channels in the channel layout.
#define AV_CH_LAYOUT_QUAD
const char * av_get_channel_name(uint64_t channel)
Get the name of a given channel.
#define FFMAX(a, b)
Definition: common.h:55
size_t av_strlcpy(char *dst, const char *src, size_t size)
Copy the string src to dst, but no more than size - 1 bytes, and null-terminate dst.
Definition: avstring.c:81
#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
static const struct @124 channel_layout_map[]
#define AV_CH_LAYOUT_5POINT1_BACK
#define AV_CH_LAYOUT_6POINT1_BACK
NULL
Definition: eval.c:55
#define AV_CH_LAYOUT_7POINT1_WIDE_BACK
int index
Definition: gxfenc.c:72
#define AV_CH_LAYOUT_5POINT0_BACK
#define AV_CH_LAYOUT_OCTAGONAL
size_t av_strlcat(char *dst, const char *src, size_t size)
Append the string src to the string dst, but to a total length of no more than size - 1 bytes...
Definition: avstring.c:91
#define AV_CH_LAYOUT_7POINT1_WIDE
common internal and external API header
#define AV_CH_LAYOUT_2POINT1
static uint64_t get_channel_layout_single(const char *name, int name_len)
static const char *const channel_names[]
uint64_t av_get_channel_layout(const char *name)
Return a channel layout id that matches name, or 0 if no match is found.
uint64_t layout
#define AV_CH_LAYOUT_6POINT1_FRONT
int nb_channels
#define AV_CH_LAYOUT_MONO
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.