FFmpeg
channel_layout.h
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1 /*
2  * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3  * Copyright (c) 2008 Peter Ross
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #ifndef AVUTIL_CHANNEL_LAYOUT_H
23 #define AVUTIL_CHANNEL_LAYOUT_H
24 
25 #include <stdint.h>
26 #include <stdlib.h>
27 
28 #include "version.h"
29 #include "attributes.h"
30 
31 /**
32  * @file
33  * @ingroup lavu_audio_channels
34  * Public libavutil channel layout APIs header.
35  */
36 
37 
38 /**
39  * @defgroup lavu_audio_channels Audio channels
40  * @ingroup lavu_audio
41  *
42  * Audio channel layout utility functions
43  *
44  * @{
45  */
46 
47 enum AVChannel {
48  ///< Invalid channel index
68  /** Stereo downmix. */
70  /** See above. */
82  AV_CHAN_SIDE_SURROUND_LEFT, ///< +90 degrees, Lss, SiL
83  AV_CHAN_SIDE_SURROUND_RIGHT, ///< -90 degrees, Rss, SiR
84  AV_CHAN_TOP_SURROUND_LEFT, ///< +110 degrees, Lvs, TpLS
85  AV_CHAN_TOP_SURROUND_RIGHT, ///< -110 degrees, Rvs, TpRS
86 
87  /** Channel is empty can be safely skipped. */
88  AV_CHAN_UNUSED = 0x200,
89 
90  /** Channel contains data, but its position is unknown. */
91  AV_CHAN_UNKNOWN = 0x300,
92 
93  /**
94  * Range of channels between AV_CHAN_AMBISONIC_BASE and
95  * AV_CHAN_AMBISONIC_END represent Ambisonic components using the ACN system.
96  *
97  * Given a channel id `<i>` between AV_CHAN_AMBISONIC_BASE and
98  * AV_CHAN_AMBISONIC_END (inclusive), the ACN index of the channel `<n>` is
99  * `<n> = <i> - AV_CHAN_AMBISONIC_BASE`.
100  *
101  * @note these values are only used for AV_CHANNEL_ORDER_CUSTOM channel
102  * orderings, the AV_CHANNEL_ORDER_AMBISONIC ordering orders the channels
103  * implicitly by their position in the stream.
104  */
106  // leave space for 1024 ids, which correspond to maximum order-32 harmonics,
107  // which should be enough for the foreseeable use cases
109 };
110 
112  /**
113  * Only the channel count is specified, without any further information
114  * about the channel order.
115  */
117  /**
118  * The native channel order, i.e. the channels are in the same order in
119  * which they are defined in the AVChannel enum. This supports up to 63
120  * different channels.
121  */
123  /**
124  * The channel order does not correspond to any other predefined order and
125  * is stored as an explicit map. For example, this could be used to support
126  * layouts with 64 or more channels, or with empty/skipped (AV_CHAN_UNUSED)
127  * channels at arbitrary positions.
128  */
130  /**
131  * The audio is represented as the decomposition of the sound field into
132  * spherical harmonics. Each channel corresponds to a single expansion
133  * component. Channels are ordered according to ACN (Ambisonic Channel
134  * Number).
135  *
136  * The channel with the index n in the stream contains the spherical
137  * harmonic of degree l and order m given by
138  * @code{.unparsed}
139  * l = floor(sqrt(n)),
140  * m = n - l * (l + 1).
141  * @endcode
142  *
143  * Conversely given a spherical harmonic of degree l and order m, the
144  * corresponding channel index n is given by
145  * @code{.unparsed}
146  * n = l * (l + 1) + m.
147  * @endcode
148  *
149  * Normalization is assumed to be SN3D (Schmidt Semi-Normalization)
150  * as defined in AmbiX format $ 2.1.
151  */
153  /**
154  * Number of channel orders, not part of ABI/API
155  */
157 };
158 
159 
160 /**
161  * @defgroup channel_masks Audio channel masks
162  *
163  * A channel layout is a 64-bits integer with a bit set for every channel.
164  * The number of bits set must be equal to the number of channels.
165  * The value 0 means that the channel layout is not known.
166  * @note this data structure is not powerful enough to handle channels
167  * combinations that have the same channel multiple times, such as
168  * dual-mono.
169  *
170  * @{
171  */
172 #define AV_CH_FRONT_LEFT (1ULL << AV_CHAN_FRONT_LEFT )
173 #define AV_CH_FRONT_RIGHT (1ULL << AV_CHAN_FRONT_RIGHT )
174 #define AV_CH_FRONT_CENTER (1ULL << AV_CHAN_FRONT_CENTER )
175 #define AV_CH_LOW_FREQUENCY (1ULL << AV_CHAN_LOW_FREQUENCY )
176 #define AV_CH_BACK_LEFT (1ULL << AV_CHAN_BACK_LEFT )
177 #define AV_CH_BACK_RIGHT (1ULL << AV_CHAN_BACK_RIGHT )
178 #define AV_CH_FRONT_LEFT_OF_CENTER (1ULL << AV_CHAN_FRONT_LEFT_OF_CENTER )
179 #define AV_CH_FRONT_RIGHT_OF_CENTER (1ULL << AV_CHAN_FRONT_RIGHT_OF_CENTER)
180 #define AV_CH_BACK_CENTER (1ULL << AV_CHAN_BACK_CENTER )
181 #define AV_CH_SIDE_LEFT (1ULL << AV_CHAN_SIDE_LEFT )
182 #define AV_CH_SIDE_RIGHT (1ULL << AV_CHAN_SIDE_RIGHT )
183 #define AV_CH_TOP_CENTER (1ULL << AV_CHAN_TOP_CENTER )
184 #define AV_CH_TOP_FRONT_LEFT (1ULL << AV_CHAN_TOP_FRONT_LEFT )
185 #define AV_CH_TOP_FRONT_CENTER (1ULL << AV_CHAN_TOP_FRONT_CENTER )
186 #define AV_CH_TOP_FRONT_RIGHT (1ULL << AV_CHAN_TOP_FRONT_RIGHT )
187 #define AV_CH_TOP_BACK_LEFT (1ULL << AV_CHAN_TOP_BACK_LEFT )
188 #define AV_CH_TOP_BACK_CENTER (1ULL << AV_CHAN_TOP_BACK_CENTER )
189 #define AV_CH_TOP_BACK_RIGHT (1ULL << AV_CHAN_TOP_BACK_RIGHT )
190 #define AV_CH_STEREO_LEFT (1ULL << AV_CHAN_STEREO_LEFT )
191 #define AV_CH_STEREO_RIGHT (1ULL << AV_CHAN_STEREO_RIGHT )
192 #define AV_CH_WIDE_LEFT (1ULL << AV_CHAN_WIDE_LEFT )
193 #define AV_CH_WIDE_RIGHT (1ULL << AV_CHAN_WIDE_RIGHT )
194 #define AV_CH_SURROUND_DIRECT_LEFT (1ULL << AV_CHAN_SURROUND_DIRECT_LEFT )
195 #define AV_CH_SURROUND_DIRECT_RIGHT (1ULL << AV_CHAN_SURROUND_DIRECT_RIGHT)
196 #define AV_CH_LOW_FREQUENCY_2 (1ULL << AV_CHAN_LOW_FREQUENCY_2 )
197 #define AV_CH_TOP_SIDE_LEFT (1ULL << AV_CHAN_TOP_SIDE_LEFT )
198 #define AV_CH_TOP_SIDE_RIGHT (1ULL << AV_CHAN_TOP_SIDE_RIGHT )
199 #define AV_CH_BOTTOM_FRONT_CENTER (1ULL << AV_CHAN_BOTTOM_FRONT_CENTER )
200 #define AV_CH_BOTTOM_FRONT_LEFT (1ULL << AV_CHAN_BOTTOM_FRONT_LEFT )
201 #define AV_CH_BOTTOM_FRONT_RIGHT (1ULL << AV_CHAN_BOTTOM_FRONT_RIGHT )
202 #define AV_CH_SIDE_SURROUND_LEFT (1ULL << AV_CHAN_SIDE_SURROUND_LEFT )
203 #define AV_CH_SIDE_SURROUND_RIGHT (1ULL << AV_CHAN_SIDE_SURROUND_RIGHT )
204 #define AV_CH_TOP_SURROUND_LEFT (1ULL << AV_CHAN_TOP_SURROUND_LEFT )
205 #define AV_CH_TOP_SURROUND_RIGHT (1ULL << AV_CHAN_TOP_SURROUND_RIGHT )
206 
207 /**
208  * @}
209  * @defgroup channel_mask_c Audio channel layouts
210  * @{
211  * */
212 #define AV_CH_LAYOUT_MONO (AV_CH_FRONT_CENTER)
213 #define AV_CH_LAYOUT_STEREO (AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT)
214 #define AV_CH_LAYOUT_2POINT1 (AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY)
215 #define AV_CH_LAYOUT_2_1 (AV_CH_LAYOUT_STEREO|AV_CH_BACK_CENTER)
216 #define AV_CH_LAYOUT_SURROUND (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER)
217 #define AV_CH_LAYOUT_3POINT1 (AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY)
218 #define AV_CH_LAYOUT_4POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_CENTER)
219 #define AV_CH_LAYOUT_4POINT1 (AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY)
220 #define AV_CH_LAYOUT_2_2 (AV_CH_LAYOUT_STEREO|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
221 #define AV_CH_LAYOUT_QUAD (AV_CH_LAYOUT_STEREO|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
222 #define AV_CH_LAYOUT_5POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
223 #define AV_CH_LAYOUT_5POINT1 (AV_CH_LAYOUT_5POINT0|AV_CH_LOW_FREQUENCY)
224 #define AV_CH_LAYOUT_5POINT0_BACK (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
225 #define AV_CH_LAYOUT_5POINT1_BACK (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_LOW_FREQUENCY)
226 #define AV_CH_LAYOUT_6POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_CENTER)
227 #define AV_CH_LAYOUT_6POINT0_FRONT (AV_CH_LAYOUT_2_2|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
228 #define AV_CH_LAYOUT_HEXAGONAL (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_BACK_CENTER)
229 #define AV_CH_LAYOUT_3POINT1POINT2 (AV_CH_LAYOUT_3POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
230 #define AV_CH_LAYOUT_6POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_CENTER)
231 #define AV_CH_LAYOUT_6POINT1_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER)
232 #define AV_CH_LAYOUT_6POINT1_FRONT (AV_CH_LAYOUT_6POINT0_FRONT|AV_CH_LOW_FREQUENCY)
233 #define AV_CH_LAYOUT_7POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
234 #define AV_CH_LAYOUT_7POINT0_FRONT (AV_CH_LAYOUT_5POINT0|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
235 #define AV_CH_LAYOUT_7POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
236 #define AV_CH_LAYOUT_7POINT1_WIDE (AV_CH_LAYOUT_5POINT1|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
237 #define AV_CH_LAYOUT_7POINT1_WIDE_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
238 #define AV_CH_LAYOUT_5POINT1POINT2_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
239 #define AV_CH_LAYOUT_OCTAGONAL (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_CENTER|AV_CH_BACK_RIGHT)
240 #define AV_CH_LAYOUT_CUBE (AV_CH_LAYOUT_QUAD|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT)
241 #define AV_CH_LAYOUT_5POINT1POINT4_BACK (AV_CH_LAYOUT_5POINT1POINT2_BACK|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT)
242 #define AV_CH_LAYOUT_7POINT1POINT2 (AV_CH_LAYOUT_7POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
243 #define AV_CH_LAYOUT_7POINT1POINT4_BACK (AV_CH_LAYOUT_7POINT1POINT2|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT)
244 #define AV_CH_LAYOUT_7POINT2POINT3 (AV_CH_LAYOUT_7POINT1POINT2|AV_CH_TOP_BACK_CENTER|AV_CH_LOW_FREQUENCY_2)
245 #define AV_CH_LAYOUT_9POINT1POINT4_BACK (AV_CH_LAYOUT_7POINT1POINT4_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
246 #define AV_CH_LAYOUT_HEXADECAGONAL (AV_CH_LAYOUT_OCTAGONAL|AV_CH_WIDE_LEFT|AV_CH_WIDE_RIGHT|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT|AV_CH_TOP_BACK_CENTER|AV_CH_TOP_FRONT_CENTER|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
247 #define AV_CH_LAYOUT_STEREO_DOWNMIX (AV_CH_STEREO_LEFT|AV_CH_STEREO_RIGHT)
248 #define AV_CH_LAYOUT_22POINT2 (AV_CH_LAYOUT_7POINT1POINT4_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER|AV_CH_BACK_CENTER|AV_CH_LOW_FREQUENCY_2|AV_CH_TOP_FRONT_CENTER|AV_CH_TOP_CENTER|AV_CH_TOP_SIDE_LEFT|AV_CH_TOP_SIDE_RIGHT|AV_CH_TOP_BACK_CENTER|AV_CH_BOTTOM_FRONT_CENTER|AV_CH_BOTTOM_FRONT_LEFT|AV_CH_BOTTOM_FRONT_RIGHT)
249 
250 #define AV_CH_LAYOUT_7POINT1_TOP_BACK AV_CH_LAYOUT_5POINT1POINT2_BACK
251 
261 };
262 
263 /**
264  * @}
265  */
266 
267 /**
268  * An AVChannelCustom defines a single channel within a custom order layout
269  *
270  * Unlike most structures in FFmpeg, sizeof(AVChannelCustom) is a part of the
271  * public ABI.
272  *
273  * No new fields may be added to it without a major version bump.
274  */
275 typedef struct AVChannelCustom {
276  enum AVChannel id;
277  char name[16];
278  void *opaque;
280 
281 /**
282  * An AVChannelLayout holds information about the channel layout of audio data.
283  *
284  * A channel layout here is defined as a set of channels ordered in a specific
285  * way (unless the channel order is AV_CHANNEL_ORDER_UNSPEC, in which case an
286  * AVChannelLayout carries only the channel count).
287  * All orders may be treated as if they were AV_CHANNEL_ORDER_UNSPEC by
288  * ignoring everything but the channel count, as long as av_channel_layout_check()
289  * considers they are valid.
290  *
291  * Unlike most structures in FFmpeg, sizeof(AVChannelLayout) is a part of the
292  * public ABI and may be used by the caller. E.g. it may be allocated on stack
293  * or embedded in caller-defined structs.
294  *
295  * AVChannelLayout can be initialized as follows:
296  * - default initialization with {0}, followed by setting all used fields
297  * correctly;
298  * - by assigning one of the predefined AV_CHANNEL_LAYOUT_* initializers;
299  * - with a constructor function, such as av_channel_layout_default(),
300  * av_channel_layout_from_mask() or av_channel_layout_from_string().
301  *
302  * The channel layout must be unitialized with av_channel_layout_uninit()
303  *
304  * Copying an AVChannelLayout via assigning is forbidden,
305  * av_channel_layout_copy() must be used instead (and its return value should
306  * be checked)
307  *
308  * No new fields may be added to it without a major version bump, except for
309  * new elements of the union fitting in sizeof(uint64_t).
310  */
311 typedef struct AVChannelLayout {
312  /**
313  * Channel order used in this layout.
314  * This is a mandatory field.
315  */
317 
318  /**
319  * Number of channels in this layout. Mandatory field.
320  */
322 
323  /**
324  * Details about which channels are present in this layout.
325  * For AV_CHANNEL_ORDER_UNSPEC, this field is undefined and must not be
326  * used.
327  */
328  union {
329  /**
330  * This member must be used for AV_CHANNEL_ORDER_NATIVE, and may be used
331  * for AV_CHANNEL_ORDER_AMBISONIC to signal non-diegetic channels.
332  * It is a bitmask, where the position of each set bit means that the
333  * AVChannel with the corresponding value is present.
334  *
335  * I.e. when (mask & (1 << AV_CHAN_FOO)) is non-zero, then AV_CHAN_FOO
336  * is present in the layout. Otherwise it is not present.
337  *
338  * @note when a channel layout using a bitmask is constructed or
339  * modified manually (i.e. not using any of the av_channel_layout_*
340  * functions), the code doing it must ensure that the number of set bits
341  * is equal to nb_channels.
342  */
343  uint64_t mask;
344  /**
345  * This member must be used when the channel order is
346  * AV_CHANNEL_ORDER_CUSTOM. It is a nb_channels-sized array, with each
347  * element signalling the presence of the AVChannel with the
348  * corresponding value in map[i].id.
349  *
350  * I.e. when map[i].id is equal to AV_CHAN_FOO, then AV_CH_FOO is the
351  * i-th channel in the audio data.
352  *
353  * When map[i].id is in the range between AV_CHAN_AMBISONIC_BASE and
354  * AV_CHAN_AMBISONIC_END (inclusive), the channel contains an ambisonic
355  * component with ACN index (as defined above)
356  * n = map[i].id - AV_CHAN_AMBISONIC_BASE.
357  *
358  * map[i].name may be filled with a 0-terminated string, in which case
359  * it will be used for the purpose of identifying the channel with the
360  * convenience functions below. Otherise it must be zeroed.
361  */
363  } u;
364 
365  /**
366  * For some private data of the user.
367  */
368  void *opaque;
370 
371 /**
372  * Macro to define native channel layouts
373  *
374  * @note This doesn't use designated initializers for compatibility with C++ 17 and older.
375  */
376 #define AV_CHANNEL_LAYOUT_MASK(nb, m) \
377  { /* .order */ AV_CHANNEL_ORDER_NATIVE, \
378  /* .nb_channels */ (nb), \
379  /* .u.mask */ { m }, \
380  /* .opaque */ NULL }
381 
382 /**
383  * @name Common pre-defined channel layouts
384  * @{
385  */
386 #define AV_CHANNEL_LAYOUT_MONO AV_CHANNEL_LAYOUT_MASK(1, AV_CH_LAYOUT_MONO)
387 #define AV_CHANNEL_LAYOUT_STEREO AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO)
388 #define AV_CHANNEL_LAYOUT_2POINT1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2POINT1)
389 #define AV_CHANNEL_LAYOUT_2_1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2_1)
390 #define AV_CHANNEL_LAYOUT_SURROUND AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_SURROUND)
391 #define AV_CHANNEL_LAYOUT_3POINT1 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_3POINT1)
392 #define AV_CHANNEL_LAYOUT_4POINT0 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_4POINT0)
393 #define AV_CHANNEL_LAYOUT_4POINT1 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_4POINT1)
394 #define AV_CHANNEL_LAYOUT_2_2 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_2_2)
395 #define AV_CHANNEL_LAYOUT_QUAD AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_QUAD)
396 #define AV_CHANNEL_LAYOUT_5POINT0 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0)
397 #define AV_CHANNEL_LAYOUT_5POINT1 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1)
398 #define AV_CHANNEL_LAYOUT_5POINT0_BACK AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0_BACK)
399 #define AV_CHANNEL_LAYOUT_5POINT1_BACK AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1_BACK)
400 #define AV_CHANNEL_LAYOUT_6POINT0 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0)
401 #define AV_CHANNEL_LAYOUT_6POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0_FRONT)
402 #define AV_CHANNEL_LAYOUT_3POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_3POINT1POINT2)
403 #define AV_CHANNEL_LAYOUT_HEXAGONAL AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_HEXAGONAL)
404 #define AV_CHANNEL_LAYOUT_6POINT1 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1)
405 #define AV_CHANNEL_LAYOUT_6POINT1_BACK AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_BACK)
406 #define AV_CHANNEL_LAYOUT_6POINT1_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_FRONT)
407 #define AV_CHANNEL_LAYOUT_7POINT0 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0)
408 #define AV_CHANNEL_LAYOUT_7POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0_FRONT)
409 #define AV_CHANNEL_LAYOUT_7POINT1 AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1)
410 #define AV_CHANNEL_LAYOUT_7POINT1_WIDE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE)
411 #define AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE_BACK)
412 #define AV_CHANNEL_LAYOUT_5POINT1POINT2_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_5POINT1POINT2_BACK)
413 #define AV_CHANNEL_LAYOUT_OCTAGONAL AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_OCTAGONAL)
414 #define AV_CHANNEL_LAYOUT_CUBE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_CUBE)
415 #define AV_CHANNEL_LAYOUT_5POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(10, AV_CH_LAYOUT_5POINT1POINT4_BACK)
416 #define AV_CHANNEL_LAYOUT_7POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(10, AV_CH_LAYOUT_7POINT1POINT2)
417 #define AV_CHANNEL_LAYOUT_7POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(12, AV_CH_LAYOUT_7POINT1POINT4_BACK)
418 #define AV_CHANNEL_LAYOUT_7POINT2POINT3 AV_CHANNEL_LAYOUT_MASK(12, AV_CH_LAYOUT_7POINT2POINT3)
419 #define AV_CHANNEL_LAYOUT_9POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(14, AV_CH_LAYOUT_9POINT1POINT4_BACK)
420 #define AV_CHANNEL_LAYOUT_HEXADECAGONAL AV_CHANNEL_LAYOUT_MASK(16, AV_CH_LAYOUT_HEXADECAGONAL)
421 #define AV_CHANNEL_LAYOUT_STEREO_DOWNMIX AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO_DOWNMIX)
422 #define AV_CHANNEL_LAYOUT_22POINT2 AV_CHANNEL_LAYOUT_MASK(24, AV_CH_LAYOUT_22POINT2)
423 
424 #define AV_CHANNEL_LAYOUT_7POINT1_TOP_BACK AV_CHANNEL_LAYOUT_5POINT1POINT2_BACK
425 
426 #define AV_CHANNEL_LAYOUT_AMBISONIC_FIRST_ORDER \
427  { /* .order */ AV_CHANNEL_ORDER_AMBISONIC, \
428  /* .nb_channels */ 4, \
429  /* .u.mask */ { 0 }, \
430  /* .opaque */ NULL }
431 /** @} */
432 
433 struct AVBPrint;
434 
435 /**
436  * Get a human readable string in an abbreviated form describing a given channel.
437  * This is the inverse function of @ref av_channel_from_string().
438  *
439  * @param buf pre-allocated buffer where to put the generated string
440  * @param buf_size size in bytes of the buffer.
441  * @param channel the AVChannel whose name to get
442  * @return amount of bytes needed to hold the output string, or a negative AVERROR
443  * on failure. If the returned value is bigger than buf_size, then the
444  * string was truncated.
445  */
446 int av_channel_name(char *buf, size_t buf_size, enum AVChannel channel);
447 
448 /**
449  * bprint variant of av_channel_name().
450  *
451  * @note the string will be appended to the bprint buffer.
452  */
453 void av_channel_name_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
454 
455 /**
456  * Get a human readable string describing a given channel.
457  *
458  * @param buf pre-allocated buffer where to put the generated string
459  * @param buf_size size in bytes of the buffer.
460  * @param channel the AVChannel whose description to get
461  * @return amount of bytes needed to hold the output string, or a negative AVERROR
462  * on failure. If the returned value is bigger than buf_size, then the
463  * string was truncated.
464  */
465 int av_channel_description(char *buf, size_t buf_size, enum AVChannel channel);
466 
467 /**
468  * bprint variant of av_channel_description().
469  *
470  * @note the string will be appended to the bprint buffer.
471  */
472 void av_channel_description_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
473 
474 /**
475  * This is the inverse function of @ref av_channel_name().
476  *
477  * @return the channel with the given name
478  * AV_CHAN_NONE when name does not identify a known channel
479  */
480 enum AVChannel av_channel_from_string(const char *name);
481 
482 /**
483  * Initialize a custom channel layout with the specified number of channels.
484  * The channel map will be allocated and the designation of all channels will
485  * be set to AV_CHAN_UNKNOWN.
486  *
487  * This is only a convenience helper function, a custom channel layout can also
488  * be constructed without using this.
489  *
490  * @param channel_layout the layout structure to be initialized
491  * @param nb_channels the number of channels
492  *
493  * @return 0 on success
494  * AVERROR(EINVAL) if the number of channels <= 0
495  * AVERROR(ENOMEM) if the channel map could not be allocated
496  */
497 int av_channel_layout_custom_init(AVChannelLayout *channel_layout, int nb_channels);
498 
499 /**
500  * Initialize a native channel layout from a bitmask indicating which channels
501  * are present.
502  *
503  * @param channel_layout the layout structure to be initialized
504  * @param mask bitmask describing the channel layout
505  *
506  * @return 0 on success
507  * AVERROR(EINVAL) for invalid mask values
508  */
509 int av_channel_layout_from_mask(AVChannelLayout *channel_layout, uint64_t mask);
510 
511 /**
512  * Initialize a channel layout from a given string description.
513  * The input string can be represented by:
514  * - the formal channel layout name (returned by av_channel_layout_describe())
515  * - single or multiple channel names (returned by av_channel_name(), eg. "FL",
516  * or concatenated with "+", each optionally containing a custom name after
517  * a "@", eg. "FL@Left+FR@Right+LFE")
518  * - a decimal or hexadecimal value of a native channel layout (eg. "4" or "0x4")
519  * - the number of channels with default layout (eg. "4c")
520  * - the number of unordered channels (eg. "4C" or "4 channels")
521  * - the ambisonic order followed by optional non-diegetic channels (eg.
522  * "ambisonic 2+stereo")
523  * On error, the channel layout will remain uninitialized, but not necessarily
524  * untouched.
525  *
526  * @param channel_layout uninitialized channel layout for the result
527  * @param str string describing the channel layout
528  * @return 0 on success parsing the channel layout
529  * AVERROR(EINVAL) if an invalid channel layout string was provided
530  * AVERROR(ENOMEM) if there was not enough memory
531  */
533  const char *str);
534 
535 /**
536  * Get the default channel layout for a given number of channels.
537  *
538  * @param ch_layout the layout structure to be initialized
539  * @param nb_channels number of channels
540  */
541 void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels);
542 
543 /**
544  * Iterate over all standard channel layouts.
545  *
546  * @param opaque a pointer where libavutil will store the iteration state. Must
547  * point to NULL to start the iteration.
548  *
549  * @return the standard channel layout or NULL when the iteration is
550  * finished
551  */
552 const AVChannelLayout *av_channel_layout_standard(void **opaque);
553 
554 /**
555  * Free any allocated data in the channel layout and reset the channel
556  * count to 0.
557  *
558  * @param channel_layout the layout structure to be uninitialized
559  */
560 void av_channel_layout_uninit(AVChannelLayout *channel_layout);
561 
562 /**
563  * Make a copy of a channel layout. This differs from just assigning src to dst
564  * in that it allocates and copies the map for AV_CHANNEL_ORDER_CUSTOM.
565  *
566  * @note the destination channel_layout will be always uninitialized before copy.
567  *
568  * @param dst destination channel layout
569  * @param src source channel layout
570  * @return 0 on success, a negative AVERROR on error.
571  */
573 
574 /**
575  * Get a human-readable string describing the channel layout properties.
576  * The string will be in the same format that is accepted by
577  * @ref av_channel_layout_from_string(), allowing to rebuild the same
578  * channel layout, except for opaque pointers.
579  *
580  * @param channel_layout channel layout to be described
581  * @param buf pre-allocated buffer where to put the generated string
582  * @param buf_size size in bytes of the buffer.
583  * @return amount of bytes needed to hold the output string, or a negative AVERROR
584  * on failure. If the returned value is bigger than buf_size, then the
585  * string was truncated.
586  */
587 int av_channel_layout_describe(const AVChannelLayout *channel_layout,
588  char *buf, size_t buf_size);
589 
590 /**
591  * bprint variant of av_channel_layout_describe().
592  *
593  * @note the string will be appended to the bprint buffer.
594  * @return 0 on success, or a negative AVERROR value on failure.
595  */
596 int av_channel_layout_describe_bprint(const AVChannelLayout *channel_layout,
597  struct AVBPrint *bp);
598 
599 /**
600  * Get the channel with the given index in a channel layout.
601  *
602  * @param channel_layout input channel layout
603  * @param idx index of the channel
604  * @return channel with the index idx in channel_layout on success or
605  * AV_CHAN_NONE on failure (if idx is not valid or the channel order is
606  * unspecified)
607  */
608 enum AVChannel
609 av_channel_layout_channel_from_index(const AVChannelLayout *channel_layout, unsigned int idx);
610 
611 /**
612  * Get the index of a given channel in a channel layout. In case multiple
613  * channels are found, only the first match will be returned.
614  *
615  * @param channel_layout input channel layout
616  * @param channel the channel whose index to obtain
617  * @return index of channel in channel_layout on success or a negative number if
618  * channel is not present in channel_layout.
619  */
620 int av_channel_layout_index_from_channel(const AVChannelLayout *channel_layout,
621  enum AVChannel channel);
622 
623 /**
624  * Get the index in a channel layout of a channel described by the given string.
625  * In case multiple channels are found, only the first match will be returned.
626  *
627  * This function accepts channel names in the same format as
628  * @ref av_channel_from_string().
629  *
630  * @param channel_layout input channel layout
631  * @param name string describing the channel whose index to obtain
632  * @return a channel index described by the given string, or a negative AVERROR
633  * value.
634  */
635 int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout,
636  const char *name);
637 
638 /**
639  * Get a channel described by the given string.
640  *
641  * This function accepts channel names in the same format as
642  * @ref av_channel_from_string().
643  *
644  * @param channel_layout input channel layout
645  * @param name string describing the channel to obtain
646  * @return a channel described by the given string in channel_layout on success
647  * or AV_CHAN_NONE on failure (if the string is not valid or the channel
648  * order is unspecified)
649  */
650 enum AVChannel
652  const char *name);
653 
654 /**
655  * Find out what channels from a given set are present in a channel layout,
656  * without regard for their positions.
657  *
658  * @param channel_layout input channel layout
659  * @param mask a combination of AV_CH_* representing a set of channels
660  * @return a bitfield representing all the channels from mask that are present
661  * in channel_layout
662  */
663 uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout,
664  uint64_t mask);
665 
666 /**
667  * Check whether a channel layout is valid, i.e. can possibly describe audio
668  * data.
669  *
670  * @param channel_layout input channel layout
671  * @return 1 if channel_layout is valid, 0 otherwise.
672  */
673 int av_channel_layout_check(const AVChannelLayout *channel_layout);
674 
675 /**
676  * Check whether two channel layouts are semantically the same, i.e. the same
677  * channels are present on the same positions in both.
678  *
679  * If one of the channel layouts is AV_CHANNEL_ORDER_UNSPEC, while the other is
680  * not, they are considered to be unequal. If both are AV_CHANNEL_ORDER_UNSPEC,
681  * they are considered equal iff the channel counts are the same in both.
682  *
683  * @param chl input channel layout
684  * @param chl1 input channel layout
685  * @return 0 if chl and chl1 are equal, 1 if they are not equal. A negative
686  * AVERROR code if one or both are invalid.
687  */
688 int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1);
689 
690 /**
691  * Return the order if the layout is n-th order standard-order ambisonic.
692  * The presence of optional extra non-diegetic channels at the end is not taken
693  * into account.
694  *
695  * @param channel_layout input channel layout
696  * @return the order of the layout, a negative error code otherwise.
697  */
698 int av_channel_layout_ambisonic_order(const AVChannelLayout *channel_layout);
699 
700 /**
701  * The conversion must be lossless.
702  */
703 #define AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS (1 << 0)
704 
705 /**
706  * The specified retype target order is ignored and the simplest possible
707  * (canonical) order is used for which the input layout can be losslessy
708  * represented.
709  */
710 #define AV_CHANNEL_LAYOUT_RETYPE_FLAG_CANONICAL (1 << 1)
711 
712 /**
713  * Change the AVChannelOrder of a channel layout.
714  *
715  * Change of AVChannelOrder can be either lossless or lossy. In case of a
716  * lossless conversion all the channel designations and the associated channel
717  * names (if any) are kept. On a lossy conversion the channel names and channel
718  * designations might be lost depending on the capabilities of the desired
719  * AVChannelOrder. Note that some conversions are simply not possible in which
720  * case this function returns AVERROR(ENOSYS).
721  *
722  * The following conversions are supported:
723  *
724  * Any -> Custom : Always possible, always lossless.
725  * Any -> Unspecified: Always possible, lossless if channel designations
726  * are all unknown and channel names are not used, lossy otherwise.
727  * Custom -> Ambisonic : Possible if it contains ambisonic channels with
728  * optional non-diegetic channels in the end. Lossy if the channels have
729  * custom names, lossless otherwise.
730  * Custom -> Native : Possible if it contains native channels in native
731  * order. Lossy if the channels have custom names, lossless otherwise.
732  *
733  * On error this function keeps the original channel layout untouched.
734  *
735  * @param channel_layout channel layout which will be changed
736  * @param order the desired channel layout order
737  * @param flags a combination of AV_CHANNEL_LAYOUT_RETYPE_FLAG_* constants
738  * @return 0 if the conversion was successful and lossless or if the channel
739  * layout was already in the desired order
740  * >0 if the conversion was successful but lossy
741  * AVERROR(ENOSYS) if the conversion was not possible (or would be
742  * lossy and AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS was specified)
743  * AVERROR(EINVAL), AVERROR(ENOMEM) on error
744  */
745 int av_channel_layout_retype(AVChannelLayout *channel_layout, enum AVChannelOrder order, int flags);
746 
747 /**
748  * @}
749  */
750 
751 #endif /* AVUTIL_CHANNEL_LAYOUT_H */
AVChannelOrder
AVChannelOrder
Definition: channel_layout.h:111
name
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option name
Definition: writing_filters.txt:88
FF_CHANNEL_ORDER_NB
@ FF_CHANNEL_ORDER_NB
Number of channel orders, not part of ABI/API.
Definition: channel_layout.h:156
AV_CHAN_WIDE_LEFT
@ AV_CHAN_WIDE_LEFT
Definition: channel_layout.h:72
AVChannelLayout::map
AVChannelCustom * map
This member must be used when the channel order is AV_CHANNEL_ORDER_CUSTOM.
Definition: channel_layout.h:362
AV_CHAN_TOP_SURROUND_LEFT
@ AV_CHAN_TOP_SURROUND_LEFT
+110 degrees, Lvs, TpLS
Definition: channel_layout.h:84
av_channel_layout_ambisonic_order
int av_channel_layout_ambisonic_order(const AVChannelLayout *channel_layout)
Return the order if the layout is n-th order standard-order ambisonic.
Definition: channel_layout.c:480
av_channel_layout_channel_from_index
enum AVChannel av_channel_layout_channel_from_index(const AVChannelLayout *channel_layout, unsigned int idx)
Get the channel with the given index in a channel layout.
Definition: channel_layout.c:668
AVChannelLayout::order
enum AVChannelOrder order
Channel order used in this layout.
Definition: channel_layout.h:316
AVChannelLayout::mask
uint64_t mask
This member must be used for AV_CHANNEL_ORDER_NATIVE, and may be used for AV_CHANNEL_ORDER_AMBISONIC ...
Definition: channel_layout.h:343
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:321
av_channel_layout_describe_bprint
int av_channel_layout_describe_bprint(const AVChannelLayout *channel_layout, struct AVBPrint *bp)
bprint variant of av_channel_layout_describe().
Definition: channel_layout.c:594
AV_CHAN_SURROUND_DIRECT_LEFT
@ AV_CHAN_SURROUND_DIRECT_LEFT
Definition: channel_layout.h:74
av_channel_description_bprint
void av_channel_description_bprint(struct AVBPrint *bp, enum AVChannel channel_id)
bprint variant of av_channel_description().
Definition: channel_layout.c:117
AV_CHAN_TOP_BACK_RIGHT
@ AV_CHAN_TOP_BACK_RIGHT
Definition: channel_layout.h:67
AV_CHAN_STEREO_RIGHT
@ AV_CHAN_STEREO_RIGHT
See above.
Definition: channel_layout.h:71
AV_CHAN_BOTTOM_FRONT_LEFT
@ AV_CHAN_BOTTOM_FRONT_LEFT
Definition: channel_layout.h:80
AV_MATRIX_ENCODING_DOLBY
@ AV_MATRIX_ENCODING_DOLBY
Definition: channel_layout.h:254
mask
static const uint16_t mask[17]
Definition: lzw.c:38
av_channel_layout_describe
int av_channel_layout_describe(const AVChannelLayout *channel_layout, char *buf, size_t buf_size)
Get a human-readable string describing the channel layout properties.
Definition: channel_layout.c:648
AVChannelCustom
An AVChannelCustom defines a single channel within a custom order layout.
Definition: channel_layout.h:275
AV_MATRIX_ENCODING_NB
@ AV_MATRIX_ENCODING_NB
Definition: channel_layout.h:260
AV_CHAN_UNKNOWN
@ AV_CHAN_UNKNOWN
Channel contains data, but its position is unknown.
Definition: channel_layout.h:91
AV_CHANNEL_ORDER_UNSPEC
@ AV_CHANNEL_ORDER_UNSPEC
Only the channel count is specified, without any further information about the channel order.
Definition: channel_layout.h:116
av_channel_layout_from_mask
int av_channel_layout_from_mask(AVChannelLayout *channel_layout, uint64_t mask)
Initialize a native channel layout from a bitmask indicating which channels are present.
Definition: channel_layout.c:247
AV_CHAN_SIDE_RIGHT
@ AV_CHAN_SIDE_RIGHT
Definition: channel_layout.h:60
av_channel_layout_index_from_string
int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout, const char *name)
Get the index in a channel layout of a channel described by the given string.
Definition: channel_layout.c:742
av_channel_layout_standard
const AVChannelLayout * av_channel_layout_standard(void **opaque)
Iterate over all standard channel layouts.
Definition: channel_layout.c:847
AV_MATRIX_ENCODING_DPLIIX
@ AV_MATRIX_ENCODING_DPLIIX
Definition: channel_layout.h:256
AV_CHAN_TOP_SIDE_LEFT
@ AV_CHAN_TOP_SIDE_LEFT
Definition: channel_layout.h:77
AV_CHAN_TOP_SIDE_RIGHT
@ AV_CHAN_TOP_SIDE_RIGHT
Definition: channel_layout.h:78
AVMatrixEncoding
AVMatrixEncoding
Definition: channel_layout.h:252
AV_CHAN_SIDE_SURROUND_LEFT
@ AV_CHAN_SIDE_SURROUND_LEFT
+90 degrees, Lss, SiL
Definition: channel_layout.h:82
AV_MATRIX_ENCODING_DOLBYHEADPHONE
@ AV_MATRIX_ENCODING_DOLBYHEADPHONE
Definition: channel_layout.h:259
AV_CHANNEL_ORDER_AMBISONIC
@ AV_CHANNEL_ORDER_AMBISONIC
The audio is represented as the decomposition of the sound field into spherical harmonics.
Definition: channel_layout.h:152
AV_CHAN_TOP_BACK_CENTER
@ AV_CHAN_TOP_BACK_CENTER
Definition: channel_layout.h:66
AV_CHAN_BOTTOM_FRONT_RIGHT
@ AV_CHAN_BOTTOM_FRONT_RIGHT
Definition: channel_layout.h:81
AV_CHAN_TOP_CENTER
@ AV_CHAN_TOP_CENTER
Definition: channel_layout.h:61
AV_CHAN_FRONT_RIGHT_OF_CENTER
@ AV_CHAN_FRONT_RIGHT_OF_CENTER
Definition: channel_layout.h:57
AV_CHAN_FRONT_RIGHT
@ AV_CHAN_FRONT_RIGHT
Definition: channel_layout.h:51
AV_CHAN_FRONT_CENTER
@ AV_CHAN_FRONT_CENTER
Definition: channel_layout.h:52
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:311
AV_MATRIX_ENCODING_NONE
@ AV_MATRIX_ENCODING_NONE
Definition: channel_layout.h:253
AVChannelLayout::u
union AVChannelLayout::@398 u
Details about which channels are present in this layout.
AV_CHAN_LOW_FREQUENCY
@ AV_CHAN_LOW_FREQUENCY
Definition: channel_layout.h:53
AV_CHAN_BACK_RIGHT
@ AV_CHAN_BACK_RIGHT
Definition: channel_layout.h:55
AV_CHAN_SIDE_LEFT
@ AV_CHAN_SIDE_LEFT
Definition: channel_layout.h:59
AV_CHAN_AMBISONIC_END
@ AV_CHAN_AMBISONIC_END
Definition: channel_layout.h:108
av_channel_description
int av_channel_description(char *buf, size_t buf_size, enum AVChannel channel)
Get a human readable string describing a given channel.
Definition: channel_layout.c:135
av_channel_layout_retype
int av_channel_layout_retype(AVChannelLayout *channel_layout, enum AVChannelOrder order, int flags)
Change the AVChannelOrder of a channel layout.
Definition: channel_layout.c:880
AV_CHAN_TOP_FRONT_RIGHT
@ AV_CHAN_TOP_FRONT_RIGHT
Definition: channel_layout.h:64
attributes.h
AV_CHANNEL_ORDER_NATIVE
@ AV_CHANNEL_ORDER_NATIVE
The native channel order, i.e.
Definition: channel_layout.h:122
AV_CHAN_FRONT_LEFT_OF_CENTER
@ AV_CHAN_FRONT_LEFT_OF_CENTER
Definition: channel_layout.h:56
AV_CHAN_UNUSED
@ AV_CHAN_UNUSED
Channel is empty can be safely skipped.
Definition: channel_layout.h:88
av_channel_layout_compare
int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1)
Check whether two channel layouts are semantically the same, i.e.
Definition: channel_layout.c:804
av_channel_layout_custom_init
int av_channel_layout_custom_init(AVChannelLayout *channel_layout, int nb_channels)
Initialize a custom channel layout with the specified number of channels.
Definition: channel_layout.c:227
av_channel_layout_default
void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels)
Get the default channel layout for a given number of channels.
Definition: channel_layout.c:834
AVChannel
AVChannel
Definition: channel_layout.h:47
AV_CHAN_TOP_SURROUND_RIGHT
@ AV_CHAN_TOP_SURROUND_RIGHT
-110 degrees, Rvs, TpRS
Definition: channel_layout.h:85
av_channel_layout_from_string
int av_channel_layout_from_string(AVChannelLayout *channel_layout, const char *str)
Initialize a channel layout from a given string description.
Definition: channel_layout.c:307
AV_CHAN_SURROUND_DIRECT_RIGHT
@ AV_CHAN_SURROUND_DIRECT_RIGHT
Definition: channel_layout.h:75
av_channel_name
int av_channel_name(char *buf, size_t buf_size, enum AVChannel channel)
Get a human readable string in an abbreviated form describing a given channel.
Definition: channel_layout.c:102
AVChannelCustom::name
char name[16]
Definition: channel_layout.h:277
AV_CHAN_STEREO_LEFT
@ AV_CHAN_STEREO_LEFT
Stereo downmix.
Definition: channel_layout.h:69
version.h
av_channel_layout_check
int av_channel_layout_check(const AVChannelLayout *channel_layout)
Check whether a channel layout is valid, i.e.
Definition: channel_layout.c:778
AV_CHAN_BACK_CENTER
@ AV_CHAN_BACK_CENTER
Definition: channel_layout.h:58
av_channel_from_string
enum AVChannel av_channel_from_string(const char *name)
This is the inverse function of av_channel_name().
Definition: channel_layout.c:150
AV_CHAN_NONE
@ AV_CHAN_NONE
Invalid channel index.
Definition: channel_layout.h:49
AVChannelCustom::opaque
void * opaque
Definition: channel_layout.h:278
AV_CHANNEL_ORDER_CUSTOM
@ AV_CHANNEL_ORDER_CUSTOM
The channel order does not correspond to any other predefined order and is stored as an explicit map.
Definition: channel_layout.h:129
AVChannelLayout::opaque
void * opaque
For some private data of the user.
Definition: channel_layout.h:368
AV_CHAN_LOW_FREQUENCY_2
@ AV_CHAN_LOW_FREQUENCY_2
Definition: channel_layout.h:76
av_channel_layout_subset
uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout, uint64_t mask)
Find out what channels from a given set are present in a channel layout, without regard for their pos...
Definition: channel_layout.c:860
AV_CHAN_TOP_BACK_LEFT
@ AV_CHAN_TOP_BACK_LEFT
Definition: channel_layout.h:65
AV_MATRIX_ENCODING_DOLBYEX
@ AV_MATRIX_ENCODING_DOLBYEX
Definition: channel_layout.h:258
av_channel_layout_channel_from_string
enum AVChannel av_channel_layout_channel_from_string(const AVChannelLayout *channel_layout, const char *name)
Get a channel described by the given string.
Definition: channel_layout.c:697
av_channel_layout_index_from_channel
int av_channel_layout_index_from_channel(const AVChannelLayout *channel_layout, enum AVChannel channel)
Get the index of a given channel in a channel layout.
Definition: channel_layout.c:708
av_channel_layout_uninit
void av_channel_layout_uninit(AVChannelLayout *channel_layout)
Free any allocated data in the channel layout and reset the channel count to 0.
Definition: channel_layout.c:437
AV_CHAN_BACK_LEFT
@ AV_CHAN_BACK_LEFT
Definition: channel_layout.h:54
AV_CHAN_BOTTOM_FRONT_CENTER
@ AV_CHAN_BOTTOM_FRONT_CENTER
Definition: channel_layout.h:79
av_channel_layout_copy
int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src)
Make a copy of a channel layout.
Definition: channel_layout.c:444
AV_CHAN_TOP_FRONT_CENTER
@ AV_CHAN_TOP_FRONT_CENTER
Definition: channel_layout.h:63
AV_CHAN_SIDE_SURROUND_RIGHT
@ AV_CHAN_SIDE_SURROUND_RIGHT
-90 degrees, Rss, SiR
Definition: channel_layout.h:83
AV_CHAN_WIDE_RIGHT
@ AV_CHAN_WIDE_RIGHT
Definition: channel_layout.h:73
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
AV_CHAN_TOP_FRONT_LEFT
@ AV_CHAN_TOP_FRONT_LEFT
Definition: channel_layout.h:62
AV_MATRIX_ENCODING_DPLIIZ
@ AV_MATRIX_ENCODING_DPLIIZ
Definition: channel_layout.h:257
AV_CHAN_AMBISONIC_BASE
@ AV_CHAN_AMBISONIC_BASE
Range of channels between AV_CHAN_AMBISONIC_BASE and AV_CHAN_AMBISONIC_END represent Ambisonic compon...
Definition: channel_layout.h:105
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
AV_CHAN_FRONT_LEFT
@ AV_CHAN_FRONT_LEFT
Definition: channel_layout.h:50
av_channel_name_bprint
void av_channel_name_bprint(struct AVBPrint *bp, enum AVChannel channel_id)
bprint variant of av_channel_name().
Definition: channel_layout.c:84
AVChannelCustom::id
enum AVChannel id
Definition: channel_layout.h:276
channel
channel
Definition: ebur128.h:39
AV_MATRIX_ENCODING_DPLII
@ AV_MATRIX_ENCODING_DPLII
Definition: channel_layout.h:255