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 "avstring.h"
27 #include "avutil.h"
28 #include "channel_layout.h"
29 #include "common.h"
30 
31 static const char * const channel_names[] = {
32  [0] = "FL", /* front left */
33  [1] = "FR", /* front right */
34  [2] = "FC", /* front center */
35  [3] = "LFE", /* low frequency */
36  [4] = "BL", /* back left */
37  [5] = "BR", /* back right */
38  [6] = "FLC", /* front left-of-center */
39  [7] = "FRC", /* front right-of-center */
40  [8] = "BC", /* back-center */
41  [9] = "SL", /* side left */
42  [10] = "SR", /* side right */
43  [11] = "TC", /* top center */
44  [12] = "TFL", /* top front left */
45  [13] = "TFC", /* top front center */
46  [14] = "TFR", /* top front right */
47  [15] = "TBL", /* top back left */
48  [16] = "TBC", /* top back center */
49  [17] = "TBR", /* top back right */
50  [29] = "DL", /* downmix left */
51  [30] = "DR", /* downmix right */
52  [31] = "WL", /* wide left */
53  [32] = "WR", /* wide right */
54  [33] = "SDL", /* surround direct left */
55  [34] = "SDR", /* surround direct right */
56  [35] = "LFE2", /* low frequency 2 */
57 };
58 
59 static const char *get_channel_name(int channel_id)
60 {
61  if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
62  return NULL;
63  return channel_names[channel_id];
64 }
65 
66 static const struct {
67  const char *name;
69  uint64_t layout;
70 } channel_layout_map[] = {
71  { "mono", 1, AV_CH_LAYOUT_MONO },
72  { "stereo", 2, AV_CH_LAYOUT_STEREO },
73  { "stereo", 2, AV_CH_LAYOUT_STEREO_DOWNMIX },
74  { "2.1", 3, AV_CH_LAYOUT_2POINT1 },
75  { "3.0", 3, AV_CH_LAYOUT_SURROUND },
76  { "3.0(back)", 3, AV_CH_LAYOUT_2_1 },
77  { "3.1", 4, AV_CH_LAYOUT_3POINT1 },
78  { "4.0", 4, AV_CH_LAYOUT_4POINT0 },
79  { "quad", 4, AV_CH_LAYOUT_QUAD },
80  { "quad(side)", 4, AV_CH_LAYOUT_2_2 },
81  { "4.1", 5, AV_CH_LAYOUT_4POINT1 },
82  { "5.0", 5, AV_CH_LAYOUT_5POINT0 },
83  { "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },
84  { "5.1", 6, AV_CH_LAYOUT_5POINT1 },
85  { "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },
86  { "6.0", 6, AV_CH_LAYOUT_6POINT0 },
87  { "6.0(front)", 6, AV_CH_LAYOUT_6POINT0_FRONT },
88  { "hexagonal", 6, AV_CH_LAYOUT_HEXAGONAL },
89  { "6.1", 7, AV_CH_LAYOUT_6POINT1 },
90  { "6.1", 7, AV_CH_LAYOUT_6POINT1_BACK },
91  { "6.1(front)", 7, AV_CH_LAYOUT_6POINT1_FRONT },
92  { "7.0", 7, AV_CH_LAYOUT_7POINT0 },
93  { "7.0(front)", 7, AV_CH_LAYOUT_7POINT0_FRONT },
94  { "7.1", 8, AV_CH_LAYOUT_7POINT1 },
95  { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
96  { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE_BACK },
97  { "octagonal", 8, AV_CH_LAYOUT_OCTAGONAL },
98  { "downmix", 2, AV_CH_LAYOUT_STEREO_DOWNMIX, },
99  { 0 }
100 };
101 
102 static uint64_t get_channel_layout_single(const char *name, int name_len)
103 {
104  int i;
105  char *end;
106  int64_t layout;
107 
108  for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map) - 1; i++) {
109  if (strlen(channel_layout_map[i].name) == name_len &&
110  !memcmp(channel_layout_map[i].name, name, name_len))
111  return channel_layout_map[i].layout;
112  }
113  for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
114  if (channel_names[i] &&
115  strlen(channel_names[i]) == name_len &&
116  !memcmp(channel_names[i], name, name_len))
117  return (int64_t)1 << i;
118  i = strtol(name, &end, 10);
119  if (end - name == name_len ||
120  (end + 1 - name == name_len && *end == 'c'))
122  layout = strtoll(name, &end, 0);
123  if (end - name == name_len)
124  return FFMAX(layout, 0);
125  return 0;
126 }
127 
128 uint64_t av_get_channel_layout(const char *name)
129 {
130  const char *n, *e;
131  const char *name_end = name + strlen(name);
132  int64_t layout = 0, layout_single;
133 
134  for (n = name; n < name_end; n = e + 1) {
135  for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
136  layout_single = get_channel_layout_single(n, e - n);
137  if (!layout_single)
138  return 0;
139  layout |= layout_single;
140  }
141  return layout;
142 }
143 
144 void av_get_channel_layout_string(char *buf, int buf_size,
145  int nb_channels, uint64_t channel_layout)
146 {
147  int i;
148 
149  if (nb_channels <= 0)
150  nb_channels = av_get_channel_layout_nb_channels(channel_layout);
151 
152  for (i = 0; channel_layout_map[i].name; i++)
153  if (nb_channels == channel_layout_map[i].nb_channels &&
154  channel_layout == channel_layout_map[i].layout) {
155  av_strlcpy(buf, channel_layout_map[i].name, buf_size);
156  return;
157  }
158 
159  snprintf(buf, buf_size, "%d channels", nb_channels);
160  if (channel_layout) {
161  int i, ch;
162  av_strlcat(buf, " (", buf_size);
163  for (i = 0, ch = 0; i < 64; i++) {
164  if ((channel_layout & (UINT64_C(1) << i))) {
165  const char *name = get_channel_name(i);
166  if (name) {
167  if (ch > 0)
168  av_strlcat(buf, "|", buf_size);
169  av_strlcat(buf, name, buf_size);
170  }
171  ch++;
172  }
173  }
174  av_strlcat(buf, ")", buf_size);
175  }
176 }
177 
178 int av_get_channel_layout_nb_channels(uint64_t channel_layout)
179 {
180  return av_popcount64(channel_layout);
181 }
182 
184 {
185  switch(nb_channels) {
186  case 1: return AV_CH_LAYOUT_MONO;
187  case 2: return AV_CH_LAYOUT_STEREO;
188  case 3: return AV_CH_LAYOUT_SURROUND;
189  case 4: return AV_CH_LAYOUT_QUAD;
190  case 5: return AV_CH_LAYOUT_5POINT0;
191  case 6: return AV_CH_LAYOUT_5POINT1;
192  case 7: return AV_CH_LAYOUT_6POINT1;
193  case 8: return AV_CH_LAYOUT_7POINT1;
194  default: return 0;
195  }
196 }
197 
198 int av_get_channel_layout_channel_index(uint64_t channel_layout,
199  uint64_t channel)
200 {
201  if (!(channel_layout & channel) ||
202  av_get_channel_layout_nb_channels(channel) != 1)
203  return AVERROR(EINVAL);
204  channel_layout &= channel - 1;
205  return av_get_channel_layout_nb_channels(channel_layout);
206 }
207 
208 const char *av_get_channel_name(uint64_t channel)
209 {
210  int i;
211  if (av_get_channel_layout_nb_channels(channel) != 1)
212  return NULL;
213  for (i = 0; i < 64; i++)
214  if ((1ULL<<i) & channel)
215  return get_channel_name(i);
216  return NULL;
217 }
218 
219 uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
220 {
221  int i;
222 
223  if (av_get_channel_layout_nb_channels(channel_layout) <= index)
224  return 0;
225 
226  for (i = 0; i < 64; i++) {
227  if ((1ULL << i) & channel_layout && !index--)
228  return 1ULL << i;
229  }
230  return 0;
231 }
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 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
static const struct @106 channel_layout_map[]
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.
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:67
#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
#define AV_CH_LAYOUT_5POINT1_BACK
#define AV_CH_LAYOUT_6POINT1_BACK
NULL
Definition: eval.c:52
#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:77
#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.