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 
83  /** Channel is empty can be safely skipped. */
84  AV_CHAN_UNUSED = 0x200,
85 
86  /** Channel contains data, but its position is unknown. */
87  AV_CHAN_UNKNOWN = 0x300,
88 
89  /**
90  * Range of channels between AV_CHAN_AMBISONIC_BASE and
91  * AV_CHAN_AMBISONIC_END represent Ambisonic components using the ACN system.
92  *
93  * Given a channel id `<i>` between AV_CHAN_AMBISONIC_BASE and
94  * AV_CHAN_AMBISONIC_END (inclusive), the ACN index of the channel `<n>` is
95  * `<n> = <i> - AV_CHAN_AMBISONIC_BASE`.
96  *
97  * @note these values are only used for AV_CHANNEL_ORDER_CUSTOM channel
98  * orderings, the AV_CHANNEL_ORDER_AMBISONIC ordering orders the channels
99  * implicitly by their position in the stream.
100  */
102  // leave space for 1024 ids, which correspond to maximum order-32 harmonics,
103  // which should be enough for the foreseeable use cases
105 };
106 
108  /**
109  * Only the channel count is specified, without any further information
110  * about the channel order.
111  */
113  /**
114  * The native channel order, i.e. the channels are in the same order in
115  * which they are defined in the AVChannel enum. This supports up to 63
116  * different channels.
117  */
119  /**
120  * The channel order does not correspond to any other predefined order and
121  * is stored as an explicit map. For example, this could be used to support
122  * layouts with 64 or more channels, or with empty/skipped (AV_CHAN_UNUSED)
123  * channels at arbitrary positions.
124  */
126  /**
127  * The audio is represented as the decomposition of the sound field into
128  * spherical harmonics. Each channel corresponds to a single expansion
129  * component. Channels are ordered according to ACN (Ambisonic Channel
130  * Number).
131  *
132  * The channel with the index n in the stream contains the spherical
133  * harmonic of degree l and order m given by
134  * @code{.unparsed}
135  * l = floor(sqrt(n)),
136  * m = n - l * (l + 1).
137  * @endcode
138  *
139  * Conversely given a spherical harmonic of degree l and order m, the
140  * corresponding channel index n is given by
141  * @code{.unparsed}
142  * n = l * (l + 1) + m.
143  * @endcode
144  *
145  * Normalization is assumed to be SN3D (Schmidt Semi-Normalization)
146  * as defined in AmbiX format $ 2.1.
147  */
149  /**
150  * Number of channel orders, not part of ABI/API
151  */
153 };
154 
155 
156 /**
157  * @defgroup channel_masks Audio channel masks
158  *
159  * A channel layout is a 64-bits integer with a bit set for every channel.
160  * The number of bits set must be equal to the number of channels.
161  * The value 0 means that the channel layout is not known.
162  * @note this data structure is not powerful enough to handle channels
163  * combinations that have the same channel multiple times, such as
164  * dual-mono.
165  *
166  * @{
167  */
168 #define AV_CH_FRONT_LEFT (1ULL << AV_CHAN_FRONT_LEFT )
169 #define AV_CH_FRONT_RIGHT (1ULL << AV_CHAN_FRONT_RIGHT )
170 #define AV_CH_FRONT_CENTER (1ULL << AV_CHAN_FRONT_CENTER )
171 #define AV_CH_LOW_FREQUENCY (1ULL << AV_CHAN_LOW_FREQUENCY )
172 #define AV_CH_BACK_LEFT (1ULL << AV_CHAN_BACK_LEFT )
173 #define AV_CH_BACK_RIGHT (1ULL << AV_CHAN_BACK_RIGHT )
174 #define AV_CH_FRONT_LEFT_OF_CENTER (1ULL << AV_CHAN_FRONT_LEFT_OF_CENTER )
175 #define AV_CH_FRONT_RIGHT_OF_CENTER (1ULL << AV_CHAN_FRONT_RIGHT_OF_CENTER)
176 #define AV_CH_BACK_CENTER (1ULL << AV_CHAN_BACK_CENTER )
177 #define AV_CH_SIDE_LEFT (1ULL << AV_CHAN_SIDE_LEFT )
178 #define AV_CH_SIDE_RIGHT (1ULL << AV_CHAN_SIDE_RIGHT )
179 #define AV_CH_TOP_CENTER (1ULL << AV_CHAN_TOP_CENTER )
180 #define AV_CH_TOP_FRONT_LEFT (1ULL << AV_CHAN_TOP_FRONT_LEFT )
181 #define AV_CH_TOP_FRONT_CENTER (1ULL << AV_CHAN_TOP_FRONT_CENTER )
182 #define AV_CH_TOP_FRONT_RIGHT (1ULL << AV_CHAN_TOP_FRONT_RIGHT )
183 #define AV_CH_TOP_BACK_LEFT (1ULL << AV_CHAN_TOP_BACK_LEFT )
184 #define AV_CH_TOP_BACK_CENTER (1ULL << AV_CHAN_TOP_BACK_CENTER )
185 #define AV_CH_TOP_BACK_RIGHT (1ULL << AV_CHAN_TOP_BACK_RIGHT )
186 #define AV_CH_STEREO_LEFT (1ULL << AV_CHAN_STEREO_LEFT )
187 #define AV_CH_STEREO_RIGHT (1ULL << AV_CHAN_STEREO_RIGHT )
188 #define AV_CH_WIDE_LEFT (1ULL << AV_CHAN_WIDE_LEFT )
189 #define AV_CH_WIDE_RIGHT (1ULL << AV_CHAN_WIDE_RIGHT )
190 #define AV_CH_SURROUND_DIRECT_LEFT (1ULL << AV_CHAN_SURROUND_DIRECT_LEFT )
191 #define AV_CH_SURROUND_DIRECT_RIGHT (1ULL << AV_CHAN_SURROUND_DIRECT_RIGHT)
192 #define AV_CH_LOW_FREQUENCY_2 (1ULL << AV_CHAN_LOW_FREQUENCY_2 )
193 #define AV_CH_TOP_SIDE_LEFT (1ULL << AV_CHAN_TOP_SIDE_LEFT )
194 #define AV_CH_TOP_SIDE_RIGHT (1ULL << AV_CHAN_TOP_SIDE_RIGHT )
195 #define AV_CH_BOTTOM_FRONT_CENTER (1ULL << AV_CHAN_BOTTOM_FRONT_CENTER )
196 #define AV_CH_BOTTOM_FRONT_LEFT (1ULL << AV_CHAN_BOTTOM_FRONT_LEFT )
197 #define AV_CH_BOTTOM_FRONT_RIGHT (1ULL << AV_CHAN_BOTTOM_FRONT_RIGHT )
198 
199 /**
200  * @}
201  * @defgroup channel_mask_c Audio channel layouts
202  * @{
203  * */
204 #define AV_CH_LAYOUT_MONO (AV_CH_FRONT_CENTER)
205 #define AV_CH_LAYOUT_STEREO (AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT)
206 #define AV_CH_LAYOUT_2POINT1 (AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY)
207 #define AV_CH_LAYOUT_2_1 (AV_CH_LAYOUT_STEREO|AV_CH_BACK_CENTER)
208 #define AV_CH_LAYOUT_SURROUND (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER)
209 #define AV_CH_LAYOUT_3POINT1 (AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY)
210 #define AV_CH_LAYOUT_4POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_CENTER)
211 #define AV_CH_LAYOUT_4POINT1 (AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY)
212 #define AV_CH_LAYOUT_2_2 (AV_CH_LAYOUT_STEREO|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
213 #define AV_CH_LAYOUT_QUAD (AV_CH_LAYOUT_STEREO|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
214 #define AV_CH_LAYOUT_5POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
215 #define AV_CH_LAYOUT_5POINT1 (AV_CH_LAYOUT_5POINT0|AV_CH_LOW_FREQUENCY)
216 #define AV_CH_LAYOUT_5POINT0_BACK (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
217 #define AV_CH_LAYOUT_5POINT1_BACK (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_LOW_FREQUENCY)
218 #define AV_CH_LAYOUT_6POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_CENTER)
219 #define AV_CH_LAYOUT_6POINT0_FRONT (AV_CH_LAYOUT_2_2|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
220 #define AV_CH_LAYOUT_HEXAGONAL (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_BACK_CENTER)
221 #define AV_CH_LAYOUT_3POINT1POINT2 (AV_CH_LAYOUT_3POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
222 #define AV_CH_LAYOUT_6POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_CENTER)
223 #define AV_CH_LAYOUT_6POINT1_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER)
224 #define AV_CH_LAYOUT_6POINT1_FRONT (AV_CH_LAYOUT_6POINT0_FRONT|AV_CH_LOW_FREQUENCY)
225 #define AV_CH_LAYOUT_7POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
226 #define AV_CH_LAYOUT_7POINT0_FRONT (AV_CH_LAYOUT_5POINT0|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
227 #define AV_CH_LAYOUT_7POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
228 #define AV_CH_LAYOUT_7POINT1_WIDE (AV_CH_LAYOUT_5POINT1|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
229 #define AV_CH_LAYOUT_7POINT1_WIDE_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
230 #define AV_CH_LAYOUT_5POINT1POINT2_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
231 #define AV_CH_LAYOUT_OCTAGONAL (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_CENTER|AV_CH_BACK_RIGHT)
232 #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)
233 #define AV_CH_LAYOUT_5POINT1POINT4_BACK (AV_CH_LAYOUT_5POINT1POINT2_BACK|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT)
234 #define AV_CH_LAYOUT_7POINT1POINT2 (AV_CH_LAYOUT_7POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
235 #define AV_CH_LAYOUT_7POINT1POINT4_BACK (AV_CH_LAYOUT_7POINT1POINT2|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT)
236 #define AV_CH_LAYOUT_7POINT2POINT3 (AV_CH_LAYOUT_7POINT1POINT2|AV_CH_TOP_BACK_CENTER|AV_CH_LOW_FREQUENCY_2)
237 #define AV_CH_LAYOUT_9POINT1POINT4_BACK (AV_CH_LAYOUT_7POINT1POINT4_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
238 #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)
239 #define AV_CH_LAYOUT_STEREO_DOWNMIX (AV_CH_STEREO_LEFT|AV_CH_STEREO_RIGHT)
240 #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)
241 
242 #define AV_CH_LAYOUT_7POINT1_TOP_BACK AV_CH_LAYOUT_5POINT1POINT2_BACK
243 
253 };
254 
255 /**
256  * @}
257  */
258 
259 /**
260  * An AVChannelCustom defines a single channel within a custom order layout
261  *
262  * Unlike most structures in FFmpeg, sizeof(AVChannelCustom) is a part of the
263  * public ABI.
264  *
265  * No new fields may be added to it without a major version bump.
266  */
267 typedef struct AVChannelCustom {
268  enum AVChannel id;
269  char name[16];
270  void *opaque;
272 
273 /**
274  * An AVChannelLayout holds information about the channel layout of audio data.
275  *
276  * A channel layout here is defined as a set of channels ordered in a specific
277  * way (unless the channel order is AV_CHANNEL_ORDER_UNSPEC, in which case an
278  * AVChannelLayout carries only the channel count).
279  * All orders may be treated as if they were AV_CHANNEL_ORDER_UNSPEC by
280  * ignoring everything but the channel count, as long as av_channel_layout_check()
281  * considers they are valid.
282  *
283  * Unlike most structures in FFmpeg, sizeof(AVChannelLayout) is a part of the
284  * public ABI and may be used by the caller. E.g. it may be allocated on stack
285  * or embedded in caller-defined structs.
286  *
287  * AVChannelLayout can be initialized as follows:
288  * - default initialization with {0}, followed by setting all used fields
289  * correctly;
290  * - by assigning one of the predefined AV_CHANNEL_LAYOUT_* initializers;
291  * - with a constructor function, such as av_channel_layout_default(),
292  * av_channel_layout_from_mask() or av_channel_layout_from_string().
293  *
294  * The channel layout must be unitialized with av_channel_layout_uninit()
295  *
296  * Copying an AVChannelLayout via assigning is forbidden,
297  * av_channel_layout_copy() must be used instead (and its return value should
298  * be checked)
299  *
300  * No new fields may be added to it without a major version bump, except for
301  * new elements of the union fitting in sizeof(uint64_t).
302  */
303 typedef struct AVChannelLayout {
304  /**
305  * Channel order used in this layout.
306  * This is a mandatory field.
307  */
309 
310  /**
311  * Number of channels in this layout. Mandatory field.
312  */
314 
315  /**
316  * Details about which channels are present in this layout.
317  * For AV_CHANNEL_ORDER_UNSPEC, this field is undefined and must not be
318  * used.
319  */
320  union {
321  /**
322  * This member must be used for AV_CHANNEL_ORDER_NATIVE, and may be used
323  * for AV_CHANNEL_ORDER_AMBISONIC to signal non-diegetic channels.
324  * It is a bitmask, where the position of each set bit means that the
325  * AVChannel with the corresponding value is present.
326  *
327  * I.e. when (mask & (1 << AV_CHAN_FOO)) is non-zero, then AV_CHAN_FOO
328  * is present in the layout. Otherwise it is not present.
329  *
330  * @note when a channel layout using a bitmask is constructed or
331  * modified manually (i.e. not using any of the av_channel_layout_*
332  * functions), the code doing it must ensure that the number of set bits
333  * is equal to nb_channels.
334  */
335  uint64_t mask;
336  /**
337  * This member must be used when the channel order is
338  * AV_CHANNEL_ORDER_CUSTOM. It is a nb_channels-sized array, with each
339  * element signalling the presence of the AVChannel with the
340  * corresponding value in map[i].id.
341  *
342  * I.e. when map[i].id is equal to AV_CHAN_FOO, then AV_CH_FOO is the
343  * i-th channel in the audio data.
344  *
345  * When map[i].id is in the range between AV_CHAN_AMBISONIC_BASE and
346  * AV_CHAN_AMBISONIC_END (inclusive), the channel contains an ambisonic
347  * component with ACN index (as defined above)
348  * n = map[i].id - AV_CHAN_AMBISONIC_BASE.
349  *
350  * map[i].name may be filled with a 0-terminated string, in which case
351  * it will be used for the purpose of identifying the channel with the
352  * convenience functions below. Otherise it must be zeroed.
353  */
355  } u;
356 
357  /**
358  * For some private data of the user.
359  */
360  void *opaque;
362 
363 /**
364  * Macro to define native channel layouts
365  *
366  * @note This doesn't use designated initializers for compatibility with C++ 17 and older.
367  */
368 #define AV_CHANNEL_LAYOUT_MASK(nb, m) \
369  { /* .order */ AV_CHANNEL_ORDER_NATIVE, \
370  /* .nb_channels */ (nb), \
371  /* .u.mask */ { m }, \
372  /* .opaque */ NULL }
373 
374 /**
375  * @name Common pre-defined channel layouts
376  * @{
377  */
378 #define AV_CHANNEL_LAYOUT_MONO AV_CHANNEL_LAYOUT_MASK(1, AV_CH_LAYOUT_MONO)
379 #define AV_CHANNEL_LAYOUT_STEREO AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO)
380 #define AV_CHANNEL_LAYOUT_2POINT1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2POINT1)
381 #define AV_CHANNEL_LAYOUT_2_1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2_1)
382 #define AV_CHANNEL_LAYOUT_SURROUND AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_SURROUND)
383 #define AV_CHANNEL_LAYOUT_3POINT1 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_3POINT1)
384 #define AV_CHANNEL_LAYOUT_4POINT0 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_4POINT0)
385 #define AV_CHANNEL_LAYOUT_4POINT1 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_4POINT1)
386 #define AV_CHANNEL_LAYOUT_2_2 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_2_2)
387 #define AV_CHANNEL_LAYOUT_QUAD AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_QUAD)
388 #define AV_CHANNEL_LAYOUT_5POINT0 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0)
389 #define AV_CHANNEL_LAYOUT_5POINT1 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1)
390 #define AV_CHANNEL_LAYOUT_5POINT0_BACK AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0_BACK)
391 #define AV_CHANNEL_LAYOUT_5POINT1_BACK AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1_BACK)
392 #define AV_CHANNEL_LAYOUT_6POINT0 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0)
393 #define AV_CHANNEL_LAYOUT_6POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0_FRONT)
394 #define AV_CHANNEL_LAYOUT_3POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_3POINT1POINT2)
395 #define AV_CHANNEL_LAYOUT_HEXAGONAL AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_HEXAGONAL)
396 #define AV_CHANNEL_LAYOUT_6POINT1 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1)
397 #define AV_CHANNEL_LAYOUT_6POINT1_BACK AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_BACK)
398 #define AV_CHANNEL_LAYOUT_6POINT1_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_FRONT)
399 #define AV_CHANNEL_LAYOUT_7POINT0 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0)
400 #define AV_CHANNEL_LAYOUT_7POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0_FRONT)
401 #define AV_CHANNEL_LAYOUT_7POINT1 AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1)
402 #define AV_CHANNEL_LAYOUT_7POINT1_WIDE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE)
403 #define AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE_BACK)
404 #define AV_CHANNEL_LAYOUT_5POINT1POINT2_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_5POINT1POINT2_BACK)
405 #define AV_CHANNEL_LAYOUT_OCTAGONAL AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_OCTAGONAL)
406 #define AV_CHANNEL_LAYOUT_CUBE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_CUBE)
407 #define AV_CHANNEL_LAYOUT_5POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(10, AV_CH_LAYOUT_5POINT1POINT4_BACK)
408 #define AV_CHANNEL_LAYOUT_7POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(10, AV_CH_LAYOUT_7POINT1POINT2)
409 #define AV_CHANNEL_LAYOUT_7POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(12, AV_CH_LAYOUT_7POINT1POINT4_BACK)
410 #define AV_CHANNEL_LAYOUT_7POINT2POINT3 AV_CHANNEL_LAYOUT_MASK(12, AV_CH_LAYOUT_7POINT2POINT3)
411 #define AV_CHANNEL_LAYOUT_9POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(14, AV_CH_LAYOUT_9POINT1POINT4_BACK)
412 #define AV_CHANNEL_LAYOUT_HEXADECAGONAL AV_CHANNEL_LAYOUT_MASK(16, AV_CH_LAYOUT_HEXADECAGONAL)
413 #define AV_CHANNEL_LAYOUT_STEREO_DOWNMIX AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO_DOWNMIX)
414 #define AV_CHANNEL_LAYOUT_22POINT2 AV_CHANNEL_LAYOUT_MASK(24, AV_CH_LAYOUT_22POINT2)
415 
416 #define AV_CHANNEL_LAYOUT_7POINT1_TOP_BACK AV_CHANNEL_LAYOUT_5POINT1POINT2_BACK
417 
418 #define AV_CHANNEL_LAYOUT_AMBISONIC_FIRST_ORDER \
419  { /* .order */ AV_CHANNEL_ORDER_AMBISONIC, \
420  /* .nb_channels */ 4, \
421  /* .u.mask */ { 0 }, \
422  /* .opaque */ NULL }
423 /** @} */
424 
425 struct AVBPrint;
426 
427 /**
428  * Get a human readable string in an abbreviated form describing a given channel.
429  * This is the inverse function of @ref av_channel_from_string().
430  *
431  * @param buf pre-allocated buffer where to put the generated string
432  * @param buf_size size in bytes of the buffer.
433  * @param channel the AVChannel whose name to get
434  * @return amount of bytes needed to hold the output string, or a negative AVERROR
435  * on failure. If the returned value is bigger than buf_size, then the
436  * string was truncated.
437  */
438 int av_channel_name(char *buf, size_t buf_size, enum AVChannel channel);
439 
440 /**
441  * bprint variant of av_channel_name().
442  *
443  * @note the string will be appended to the bprint buffer.
444  */
445 void av_channel_name_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
446 
447 /**
448  * Get a human readable string describing a given channel.
449  *
450  * @param buf pre-allocated buffer where to put the generated string
451  * @param buf_size size in bytes of the buffer.
452  * @param channel the AVChannel whose description to get
453  * @return amount of bytes needed to hold the output string, or a negative AVERROR
454  * on failure. If the returned value is bigger than buf_size, then the
455  * string was truncated.
456  */
457 int av_channel_description(char *buf, size_t buf_size, enum AVChannel channel);
458 
459 /**
460  * bprint variant of av_channel_description().
461  *
462  * @note the string will be appended to the bprint buffer.
463  */
464 void av_channel_description_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
465 
466 /**
467  * This is the inverse function of @ref av_channel_name().
468  *
469  * @return the channel with the given name
470  * AV_CHAN_NONE when name does not identify a known channel
471  */
472 enum AVChannel av_channel_from_string(const char *name);
473 
474 /**
475  * Initialize a custom channel layout with the specified number of channels.
476  * The channel map will be allocated and the designation of all channels will
477  * be set to AV_CHAN_UNKNOWN.
478  *
479  * This is only a convenience helper function, a custom channel layout can also
480  * be constructed without using this.
481  *
482  * @param channel_layout the layout structure to be initialized
483  * @param nb_channels the number of channels
484  *
485  * @return 0 on success
486  * AVERROR(EINVAL) if the number of channels <= 0
487  * AVERROR(ENOMEM) if the channel map could not be allocated
488  */
489 int av_channel_layout_custom_init(AVChannelLayout *channel_layout, int nb_channels);
490 
491 /**
492  * Initialize a native channel layout from a bitmask indicating which channels
493  * are present.
494  *
495  * @param channel_layout the layout structure to be initialized
496  * @param mask bitmask describing the channel layout
497  *
498  * @return 0 on success
499  * AVERROR(EINVAL) for invalid mask values
500  */
501 int av_channel_layout_from_mask(AVChannelLayout *channel_layout, uint64_t mask);
502 
503 /**
504  * Initialize a channel layout from a given string description.
505  * The input string can be represented by:
506  * - the formal channel layout name (returned by av_channel_layout_describe())
507  * - single or multiple channel names (returned by av_channel_name(), eg. "FL",
508  * or concatenated with "+", each optionally containing a custom name after
509  * a "@", eg. "FL@Left+FR@Right+LFE")
510  * - a decimal or hexadecimal value of a native channel layout (eg. "4" or "0x4")
511  * - the number of channels with default layout (eg. "4c")
512  * - the number of unordered channels (eg. "4C" or "4 channels")
513  * - the ambisonic order followed by optional non-diegetic channels (eg.
514  * "ambisonic 2+stereo")
515  * On error, the channel layout will remain uninitialized, but not necessarily
516  * untouched.
517  *
518  * @param channel_layout uninitialized channel layout for the result
519  * @param str string describing the channel layout
520  * @return 0 on success parsing the channel layout
521  * AVERROR(EINVAL) if an invalid channel layout string was provided
522  * AVERROR(ENOMEM) if there was not enough memory
523  */
525  const char *str);
526 
527 /**
528  * Get the default channel layout for a given number of channels.
529  *
530  * @param ch_layout the layout structure to be initialized
531  * @param nb_channels number of channels
532  */
533 void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels);
534 
535 /**
536  * Iterate over all standard channel layouts.
537  *
538  * @param opaque a pointer where libavutil will store the iteration state. Must
539  * point to NULL to start the iteration.
540  *
541  * @return the standard channel layout or NULL when the iteration is
542  * finished
543  */
544 const AVChannelLayout *av_channel_layout_standard(void **opaque);
545 
546 /**
547  * Free any allocated data in the channel layout and reset the channel
548  * count to 0.
549  *
550  * @param channel_layout the layout structure to be uninitialized
551  */
552 void av_channel_layout_uninit(AVChannelLayout *channel_layout);
553 
554 /**
555  * Make a copy of a channel layout. This differs from just assigning src to dst
556  * in that it allocates and copies the map for AV_CHANNEL_ORDER_CUSTOM.
557  *
558  * @note the destination channel_layout will be always uninitialized before copy.
559  *
560  * @param dst destination channel layout
561  * @param src source channel layout
562  * @return 0 on success, a negative AVERROR on error.
563  */
565 
566 /**
567  * Get a human-readable string describing the channel layout properties.
568  * The string will be in the same format that is accepted by
569  * @ref av_channel_layout_from_string(), allowing to rebuild the same
570  * channel layout, except for opaque pointers.
571  *
572  * @param channel_layout channel layout to be described
573  * @param buf pre-allocated buffer where to put the generated string
574  * @param buf_size size in bytes of the buffer.
575  * @return amount of bytes needed to hold the output string, or a negative AVERROR
576  * on failure. If the returned value is bigger than buf_size, then the
577  * string was truncated.
578  */
579 int av_channel_layout_describe(const AVChannelLayout *channel_layout,
580  char *buf, size_t buf_size);
581 
582 /**
583  * bprint variant of av_channel_layout_describe().
584  *
585  * @note the string will be appended to the bprint buffer.
586  * @return 0 on success, or a negative AVERROR value on failure.
587  */
588 int av_channel_layout_describe_bprint(const AVChannelLayout *channel_layout,
589  struct AVBPrint *bp);
590 
591 /**
592  * Get the channel with the given index in a channel layout.
593  *
594  * @param channel_layout input channel layout
595  * @param idx index of the channel
596  * @return channel with the index idx in channel_layout on success or
597  * AV_CHAN_NONE on failure (if idx is not valid or the channel order is
598  * unspecified)
599  */
600 enum AVChannel
601 av_channel_layout_channel_from_index(const AVChannelLayout *channel_layout, unsigned int idx);
602 
603 /**
604  * Get the index of a given channel in a channel layout. In case multiple
605  * channels are found, only the first match will be returned.
606  *
607  * @param channel_layout input channel layout
608  * @param channel the channel whose index to obtain
609  * @return index of channel in channel_layout on success or a negative number if
610  * channel is not present in channel_layout.
611  */
612 int av_channel_layout_index_from_channel(const AVChannelLayout *channel_layout,
613  enum AVChannel channel);
614 
615 /**
616  * Get the index in a channel layout of a channel described by the given string.
617  * In case multiple channels are found, only the first match will be returned.
618  *
619  * This function accepts channel names in the same format as
620  * @ref av_channel_from_string().
621  *
622  * @param channel_layout input channel layout
623  * @param name string describing the channel whose index to obtain
624  * @return a channel index described by the given string, or a negative AVERROR
625  * value.
626  */
627 int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout,
628  const char *name);
629 
630 /**
631  * Get a channel described by the given string.
632  *
633  * This function accepts channel names in the same format as
634  * @ref av_channel_from_string().
635  *
636  * @param channel_layout input channel layout
637  * @param name string describing the channel to obtain
638  * @return a channel described by the given string in channel_layout on success
639  * or AV_CHAN_NONE on failure (if the string is not valid or the channel
640  * order is unspecified)
641  */
642 enum AVChannel
644  const char *name);
645 
646 /**
647  * Find out what channels from a given set are present in a channel layout,
648  * without regard for their positions.
649  *
650  * @param channel_layout input channel layout
651  * @param mask a combination of AV_CH_* representing a set of channels
652  * @return a bitfield representing all the channels from mask that are present
653  * in channel_layout
654  */
655 uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout,
656  uint64_t mask);
657 
658 /**
659  * Check whether a channel layout is valid, i.e. can possibly describe audio
660  * data.
661  *
662  * @param channel_layout input channel layout
663  * @return 1 if channel_layout is valid, 0 otherwise.
664  */
665 int av_channel_layout_check(const AVChannelLayout *channel_layout);
666 
667 /**
668  * Check whether two channel layouts are semantically the same, i.e. the same
669  * channels are present on the same positions in both.
670  *
671  * If one of the channel layouts is AV_CHANNEL_ORDER_UNSPEC, while the other is
672  * not, they are considered to be unequal. If both are AV_CHANNEL_ORDER_UNSPEC,
673  * they are considered equal iff the channel counts are the same in both.
674  *
675  * @param chl input channel layout
676  * @param chl1 input channel layout
677  * @return 0 if chl and chl1 are equal, 1 if they are not equal. A negative
678  * AVERROR code if one or both are invalid.
679  */
680 int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1);
681 
682 /**
683  * Return the order if the layout is n-th order standard-order ambisonic.
684  * The presence of optional extra non-diegetic channels at the end is not taken
685  * into account.
686  *
687  * @param channel_layout input channel layout
688  * @return the order of the layout, a negative error code otherwise.
689  */
690 int av_channel_layout_ambisonic_order(const AVChannelLayout *channel_layout);
691 
692 /**
693  * The conversion must be lossless.
694  */
695 #define AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS (1 << 0)
696 
697 /**
698  * The specified retype target order is ignored and the simplest possible
699  * (canonical) order is used for which the input layout can be losslessy
700  * represented.
701  */
702 #define AV_CHANNEL_LAYOUT_RETYPE_FLAG_CANONICAL (1 << 1)
703 
704 /**
705  * Change the AVChannelOrder of a channel layout.
706  *
707  * Change of AVChannelOrder can be either lossless or lossy. In case of a
708  * lossless conversion all the channel designations and the associated channel
709  * names (if any) are kept. On a lossy conversion the channel names and channel
710  * designations might be lost depending on the capabilities of the desired
711  * AVChannelOrder. Note that some conversions are simply not possible in which
712  * case this function returns AVERROR(ENOSYS).
713  *
714  * The following conversions are supported:
715  *
716  * Any -> Custom : Always possible, always lossless.
717  * Any -> Unspecified: Always possible, lossless if channel designations
718  * are all unknown and channel names are not used, lossy otherwise.
719  * Custom -> Ambisonic : Possible if it contains ambisonic channels with
720  * optional non-diegetic channels in the end. Lossy if the channels have
721  * custom names, lossless otherwise.
722  * Custom -> Native : Possible if it contains native channels in native
723  * order. Lossy if the channels have custom names, lossless otherwise.
724  *
725  * On error this function keeps the original channel layout untouched.
726  *
727  * @param channel_layout channel layout which will be changed
728  * @param order the desired channel layout order
729  * @param flags a combination of AV_CHANNEL_LAYOUT_RETYPE_FLAG_* constants
730  * @return 0 if the conversion was successful and lossless or if the channel
731  * layout was already in the desired order
732  * >0 if the conversion was successful but lossy
733  * AVERROR(ENOSYS) if the conversion was not possible (or would be
734  * lossy and AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS was specified)
735  * AVERROR(EINVAL), AVERROR(ENOMEM) on error
736  */
737 int av_channel_layout_retype(AVChannelLayout *channel_layout, enum AVChannelOrder order, int flags);
738 
739 /**
740  * @}
741  */
742 
743 #endif /* AVUTIL_CHANNEL_LAYOUT_H */
AVChannelOrder
AVChannelOrder
Definition: channel_layout.h:107
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:152
AV_CHAN_WIDE_LEFT
@ AV_CHAN_WIDE_LEFT
Definition: channel_layout.h:72
AVChannelLayout::u
union AVChannelLayout::@381 u
Details about which channels are present in this layout.
AVChannelLayout::map
AVChannelCustom * map
This member must be used when the channel order is AV_CHANNEL_ORDER_CUSTOM.
Definition: channel_layout.h:354
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:476
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:664
AVChannelLayout::order
enum AVChannelOrder order
Channel order used in this layout.
Definition: channel_layout.h:308
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:335
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:313
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:590
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:113
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:246
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:644
AVChannelCustom
An AVChannelCustom defines a single channel within a custom order layout.
Definition: channel_layout.h:267
AV_MATRIX_ENCODING_NB
@ AV_MATRIX_ENCODING_NB
Definition: channel_layout.h:252
AV_CHAN_UNKNOWN
@ AV_CHAN_UNKNOWN
Channel contains data, but its position is unknown.
Definition: channel_layout.h:87
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:112
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:243
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:738
av_channel_layout_standard
const AVChannelLayout * av_channel_layout_standard(void **opaque)
Iterate over all standard channel layouts.
Definition: channel_layout.c:843
AV_MATRIX_ENCODING_DPLIIX
@ AV_MATRIX_ENCODING_DPLIIX
Definition: channel_layout.h:248
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:244
AV_MATRIX_ENCODING_DOLBYHEADPHONE
@ AV_MATRIX_ENCODING_DOLBYHEADPHONE
Definition: channel_layout.h:251
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:148
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:303
AV_MATRIX_ENCODING_NONE
@ AV_MATRIX_ENCODING_NONE
Definition: channel_layout.h:245
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:104
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:131
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:876
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:118
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:84
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:800
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:223
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:830
AVChannel
AVChannel
Definition: channel_layout.h:47
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:303
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:98
AVChannelCustom::name
char name[16]
Definition: channel_layout.h:269
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:774
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:146
AV_CHAN_NONE
@ AV_CHAN_NONE
Invalid channel index.
Definition: channel_layout.h:49
AVChannelCustom::opaque
void * opaque
Definition: channel_layout.h:270
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:125
AVChannelLayout::opaque
void * opaque
For some private data of the user.
Definition: channel_layout.h:360
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:856
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:250
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:693
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:704
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:433
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:440
AV_CHAN_TOP_FRONT_CENTER
@ AV_CHAN_TOP_FRONT_CENTER
Definition: channel_layout.h:63
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:249
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:101
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:80
AVChannelCustom::id
enum AVChannel id
Definition: channel_layout.h:268
channel
channel
Definition: ebur128.h:39
AV_MATRIX_ENCODING_DPLII
@ AV_MATRIX_ENCODING_DPLII
Definition: channel_layout.h:247