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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 
89 
90  /** Channel is empty can be safely skipped. */
91  AV_CHAN_UNUSED = 0x200,
92 
93  /** Channel contains data, but its position is unknown. */
94  AV_CHAN_UNKNOWN = 0x300,
95 
96  /**
97  * Range of channels between AV_CHAN_AMBISONIC_BASE and
98  * AV_CHAN_AMBISONIC_END represent Ambisonic components using the ACN system.
99  *
100  * Given a channel id `<i>` between AV_CHAN_AMBISONIC_BASE and
101  * AV_CHAN_AMBISONIC_END (inclusive), the ACN index of the channel `<n>` is
102  * `<n> = <i> - AV_CHAN_AMBISONIC_BASE`.
103  *
104  * @note these values are only used for AV_CHANNEL_ORDER_CUSTOM channel
105  * orderings, the AV_CHANNEL_ORDER_AMBISONIC ordering orders the channels
106  * implicitly by their position in the stream.
107  */
109  // leave space for 1024 ids, which correspond to maximum order-32 harmonics,
110  // which should be enough for the foreseeable use cases
112 };
113 
115  /**
116  * Only the channel count is specified, without any further information
117  * about the channel order.
118  */
120  /**
121  * The native channel order, i.e. the channels are in the same order in
122  * which they are defined in the AVChannel enum. This supports up to 63
123  * different channels.
124  */
126  /**
127  * The channel order does not correspond to any other predefined order and
128  * is stored as an explicit map. For example, this could be used to support
129  * layouts with 64 or more channels, or with empty/skipped (AV_CHAN_UNUSED)
130  * channels at arbitrary positions.
131  */
133  /**
134  * The audio is represented as the decomposition of the sound field into
135  * spherical harmonics. Each channel corresponds to a single expansion
136  * component. Channels are ordered according to ACN (Ambisonic Channel
137  * Number).
138  *
139  * The channel with the index n in the stream contains the spherical
140  * harmonic of degree l and order m given by
141  * @code{.unparsed}
142  * l = floor(sqrt(n)),
143  * m = n - l * (l + 1).
144  * @endcode
145  *
146  * Conversely given a spherical harmonic of degree l and order m, the
147  * corresponding channel index n is given by
148  * @code{.unparsed}
149  * n = l * (l + 1) + m.
150  * @endcode
151  *
152  * Normalization is assumed to be SN3D (Schmidt Semi-Normalization)
153  * as defined in AmbiX format $ 2.1.
154  */
156  /**
157  * Number of channel orders, not part of ABI/API
158  */
160 };
161 
162 
163 /**
164  * @defgroup channel_masks Audio channel masks
165  *
166  * A channel layout is a 64-bits integer with a bit set for every channel.
167  * The number of bits set must be equal to the number of channels.
168  * The value 0 means that the channel layout is not known.
169  * @note this data structure is not powerful enough to handle channels
170  * combinations that have the same channel multiple times, such as
171  * dual-mono.
172  *
173  * @{
174  */
175 #define AV_CH_FRONT_LEFT (1ULL << AV_CHAN_FRONT_LEFT )
176 #define AV_CH_FRONT_RIGHT (1ULL << AV_CHAN_FRONT_RIGHT )
177 #define AV_CH_FRONT_CENTER (1ULL << AV_CHAN_FRONT_CENTER )
178 #define AV_CH_LOW_FREQUENCY (1ULL << AV_CHAN_LOW_FREQUENCY )
179 #define AV_CH_BACK_LEFT (1ULL << AV_CHAN_BACK_LEFT )
180 #define AV_CH_BACK_RIGHT (1ULL << AV_CHAN_BACK_RIGHT )
181 #define AV_CH_FRONT_LEFT_OF_CENTER (1ULL << AV_CHAN_FRONT_LEFT_OF_CENTER )
182 #define AV_CH_FRONT_RIGHT_OF_CENTER (1ULL << AV_CHAN_FRONT_RIGHT_OF_CENTER)
183 #define AV_CH_BACK_CENTER (1ULL << AV_CHAN_BACK_CENTER )
184 #define AV_CH_SIDE_LEFT (1ULL << AV_CHAN_SIDE_LEFT )
185 #define AV_CH_SIDE_RIGHT (1ULL << AV_CHAN_SIDE_RIGHT )
186 #define AV_CH_TOP_CENTER (1ULL << AV_CHAN_TOP_CENTER )
187 #define AV_CH_TOP_FRONT_LEFT (1ULL << AV_CHAN_TOP_FRONT_LEFT )
188 #define AV_CH_TOP_FRONT_CENTER (1ULL << AV_CHAN_TOP_FRONT_CENTER )
189 #define AV_CH_TOP_FRONT_RIGHT (1ULL << AV_CHAN_TOP_FRONT_RIGHT )
190 #define AV_CH_TOP_BACK_LEFT (1ULL << AV_CHAN_TOP_BACK_LEFT )
191 #define AV_CH_TOP_BACK_CENTER (1ULL << AV_CHAN_TOP_BACK_CENTER )
192 #define AV_CH_TOP_BACK_RIGHT (1ULL << AV_CHAN_TOP_BACK_RIGHT )
193 #define AV_CH_STEREO_LEFT (1ULL << AV_CHAN_STEREO_LEFT )
194 #define AV_CH_STEREO_RIGHT (1ULL << AV_CHAN_STEREO_RIGHT )
195 #define AV_CH_WIDE_LEFT (1ULL << AV_CHAN_WIDE_LEFT )
196 #define AV_CH_WIDE_RIGHT (1ULL << AV_CHAN_WIDE_RIGHT )
197 #define AV_CH_SURROUND_DIRECT_LEFT (1ULL << AV_CHAN_SURROUND_DIRECT_LEFT )
198 #define AV_CH_SURROUND_DIRECT_RIGHT (1ULL << AV_CHAN_SURROUND_DIRECT_RIGHT)
199 #define AV_CH_LOW_FREQUENCY_2 (1ULL << AV_CHAN_LOW_FREQUENCY_2 )
200 #define AV_CH_TOP_SIDE_LEFT (1ULL << AV_CHAN_TOP_SIDE_LEFT )
201 #define AV_CH_TOP_SIDE_RIGHT (1ULL << AV_CHAN_TOP_SIDE_RIGHT )
202 #define AV_CH_BOTTOM_FRONT_CENTER (1ULL << AV_CHAN_BOTTOM_FRONT_CENTER )
203 #define AV_CH_BOTTOM_FRONT_LEFT (1ULL << AV_CHAN_BOTTOM_FRONT_LEFT )
204 #define AV_CH_BOTTOM_FRONT_RIGHT (1ULL << AV_CHAN_BOTTOM_FRONT_RIGHT )
205 #define AV_CH_SIDE_SURROUND_LEFT (1ULL << AV_CHAN_SIDE_SURROUND_LEFT )
206 #define AV_CH_SIDE_SURROUND_RIGHT (1ULL << AV_CHAN_SIDE_SURROUND_RIGHT )
207 #define AV_CH_TOP_SURROUND_LEFT (1ULL << AV_CHAN_TOP_SURROUND_LEFT )
208 #define AV_CH_TOP_SURROUND_RIGHT (1ULL << AV_CHAN_TOP_SURROUND_RIGHT )
209 #define AV_CH_BINAURAL_LEFT (1ULL << AV_CHAN_BINAURAL_LEFT )
210 #define AV_CH_BINAURAL_RIGHT (1ULL << AV_CHAN_BINAURAL_RIGHT )
211 
212 /**
213  * @}
214  * @defgroup channel_mask_c Audio channel layouts
215  * @{
216  * */
217 #define AV_CH_LAYOUT_MONO (AV_CH_FRONT_CENTER)
218 #define AV_CH_LAYOUT_STEREO (AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT)
219 #define AV_CH_LAYOUT_2POINT1 (AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY)
220 #define AV_CH_LAYOUT_2_1 (AV_CH_LAYOUT_STEREO|AV_CH_BACK_CENTER)
221 #define AV_CH_LAYOUT_SURROUND (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER)
222 #define AV_CH_LAYOUT_3POINT1 (AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY)
223 #define AV_CH_LAYOUT_4POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_CENTER)
224 #define AV_CH_LAYOUT_4POINT1 (AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY)
225 #define AV_CH_LAYOUT_2_2 (AV_CH_LAYOUT_STEREO|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
226 #define AV_CH_LAYOUT_QUAD (AV_CH_LAYOUT_STEREO|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
227 #define AV_CH_LAYOUT_5POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
228 #define AV_CH_LAYOUT_5POINT1 (AV_CH_LAYOUT_5POINT0|AV_CH_LOW_FREQUENCY)
229 #define AV_CH_LAYOUT_5POINT0_BACK (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
230 #define AV_CH_LAYOUT_5POINT1_BACK (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_LOW_FREQUENCY)
231 #define AV_CH_LAYOUT_6POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_CENTER)
232 #define AV_CH_LAYOUT_6POINT0_FRONT (AV_CH_LAYOUT_2_2|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
233 #define AV_CH_LAYOUT_HEXAGONAL (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_BACK_CENTER)
234 #define AV_CH_LAYOUT_3POINT1POINT2 (AV_CH_LAYOUT_3POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
235 #define AV_CH_LAYOUT_6POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_CENTER)
236 #define AV_CH_LAYOUT_6POINT1_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER)
237 #define AV_CH_LAYOUT_6POINT1_FRONT (AV_CH_LAYOUT_6POINT0_FRONT|AV_CH_LOW_FREQUENCY)
238 #define AV_CH_LAYOUT_7POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
239 #define AV_CH_LAYOUT_7POINT0_FRONT (AV_CH_LAYOUT_5POINT0|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
240 #define AV_CH_LAYOUT_7POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
241 #define AV_CH_LAYOUT_7POINT1_WIDE (AV_CH_LAYOUT_5POINT1|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
242 #define AV_CH_LAYOUT_7POINT1_WIDE_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
243 #define AV_CH_LAYOUT_5POINT1POINT2 (AV_CH_LAYOUT_5POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
244 #define AV_CH_LAYOUT_5POINT1POINT2_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
245 #define AV_CH_LAYOUT_OCTAGONAL (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_CENTER|AV_CH_BACK_RIGHT)
246 #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)
247 #define AV_CH_LAYOUT_5POINT1POINT4_BACK (AV_CH_LAYOUT_5POINT1POINT2|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT)
248 #define AV_CH_LAYOUT_7POINT1POINT2 (AV_CH_LAYOUT_7POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
249 #define AV_CH_LAYOUT_7POINT1POINT4_BACK (AV_CH_LAYOUT_7POINT1POINT2|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT)
250 #define AV_CH_LAYOUT_7POINT2POINT3 (AV_CH_LAYOUT_7POINT1POINT2|AV_CH_TOP_BACK_CENTER|AV_CH_LOW_FREQUENCY_2)
251 #define AV_CH_LAYOUT_9POINT1POINT4_BACK (AV_CH_LAYOUT_7POINT1POINT4_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
252 #define AV_CH_LAYOUT_9POINT1POINT6 (AV_CH_LAYOUT_9POINT1POINT4_BACK|AV_CH_TOP_SIDE_LEFT|AV_CH_TOP_SIDE_RIGHT)
253 #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)
254 #define AV_CH_LAYOUT_BINAURAL (AV_CH_BINAURAL_LEFT|AV_CH_BINAURAL_RIGHT)
255 #define AV_CH_LAYOUT_STEREO_DOWNMIX (AV_CH_STEREO_LEFT|AV_CH_STEREO_RIGHT)
256 #define AV_CH_LAYOUT_22POINT2 (AV_CH_LAYOUT_9POINT1POINT6|AV_CH_BACK_CENTER|AV_CH_LOW_FREQUENCY_2|AV_CH_TOP_FRONT_CENTER|AV_CH_TOP_CENTER|AV_CH_TOP_BACK_CENTER|AV_CH_BOTTOM_FRONT_CENTER|AV_CH_BOTTOM_FRONT_LEFT|AV_CH_BOTTOM_FRONT_RIGHT)
257 
258 #define AV_CH_LAYOUT_7POINT1_TOP_BACK AV_CH_LAYOUT_5POINT1POINT2_BACK
259 
269 };
270 
271 /**
272  * @}
273  */
274 
275 /**
276  * An AVChannelCustom defines a single channel within a custom order layout
277  *
278  * Unlike most structures in FFmpeg, sizeof(AVChannelCustom) is a part of the
279  * public ABI.
280  *
281  * No new fields may be added to it without a major version bump.
282  */
283 typedef struct AVChannelCustom {
284  enum AVChannel id;
285  char name[16];
286  void *opaque;
288 
289 /**
290  * An AVChannelLayout holds information about the channel layout of audio data.
291  *
292  * A channel layout here is defined as a set of channels ordered in a specific
293  * way (unless the channel order is AV_CHANNEL_ORDER_UNSPEC, in which case an
294  * AVChannelLayout carries only the channel count).
295  * All orders may be treated as if they were AV_CHANNEL_ORDER_UNSPEC by
296  * ignoring everything but the channel count, as long as av_channel_layout_check()
297  * considers they are valid.
298  *
299  * Unlike most structures in FFmpeg, sizeof(AVChannelLayout) is a part of the
300  * public ABI and may be used by the caller. E.g. it may be allocated on stack
301  * or embedded in caller-defined structs.
302  *
303  * AVChannelLayout can be initialized as follows:
304  * - default initialization with {0}, followed by setting all used fields
305  * correctly;
306  * - by assigning one of the predefined AV_CHANNEL_LAYOUT_* initializers;
307  * - with a constructor function, such as av_channel_layout_default(),
308  * av_channel_layout_from_mask() or av_channel_layout_from_string().
309  *
310  * The channel layout must be unitialized with av_channel_layout_uninit()
311  *
312  * Copying an AVChannelLayout via assigning is forbidden,
313  * av_channel_layout_copy() must be used instead (and its return value should
314  * be checked)
315  *
316  * No new fields may be added to it without a major version bump, except for
317  * new elements of the union fitting in sizeof(uint64_t).
318  */
319 typedef struct AVChannelLayout {
320  /**
321  * Channel order used in this layout.
322  * This is a mandatory field.
323  */
325 
326  /**
327  * Number of channels in this layout. Mandatory field.
328  */
330 
331  /**
332  * Details about which channels are present in this layout.
333  * For AV_CHANNEL_ORDER_UNSPEC, this field is undefined and must not be
334  * used.
335  */
336  union {
337  /**
338  * This member must be used for AV_CHANNEL_ORDER_NATIVE, and may be used
339  * for AV_CHANNEL_ORDER_AMBISONIC to signal non-diegetic channels.
340  * It is a bitmask, where the position of each set bit means that the
341  * AVChannel with the corresponding value is present.
342  *
343  * I.e. when (mask & (1 << AV_CHAN_FOO)) is non-zero, then AV_CHAN_FOO
344  * is present in the layout. Otherwise it is not present.
345  *
346  * @note when a channel layout using a bitmask is constructed or
347  * modified manually (i.e. not using any of the av_channel_layout_*
348  * functions), the code doing it must ensure that the number of set bits
349  * is equal to nb_channels.
350  */
351  uint64_t mask;
352  /**
353  * This member must be used when the channel order is
354  * AV_CHANNEL_ORDER_CUSTOM. It is a nb_channels-sized array, with each
355  * element signalling the presence of the AVChannel with the
356  * corresponding value in map[i].id.
357  *
358  * I.e. when map[i].id is equal to AV_CHAN_FOO, then AV_CH_FOO is the
359  * i-th channel in the audio data.
360  *
361  * When map[i].id is in the range between AV_CHAN_AMBISONIC_BASE and
362  * AV_CHAN_AMBISONIC_END (inclusive), the channel contains an ambisonic
363  * component with ACN index (as defined above)
364  * n = map[i].id - AV_CHAN_AMBISONIC_BASE.
365  *
366  * map[i].name may be filled with a 0-terminated string, in which case
367  * it will be used for the purpose of identifying the channel with the
368  * convenience functions below. Otherise it must be zeroed.
369  */
371  } u;
372 
373  /**
374  * For some private data of the user.
375  */
376  void *opaque;
378 
379 /**
380  * Macro to define native channel layouts
381  *
382  * @note This doesn't use designated initializers for compatibility with C++ 17 and older.
383  */
384 #define AV_CHANNEL_LAYOUT_MASK(nb, m) \
385  { /* .order */ AV_CHANNEL_ORDER_NATIVE, \
386  /* .nb_channels */ (nb), \
387  /* .u.mask */ { m }, \
388  /* .opaque */ NULL }
389 
390 /**
391  * @name Common pre-defined channel layouts
392  * @{
393  */
394 #define AV_CHANNEL_LAYOUT_MONO AV_CHANNEL_LAYOUT_MASK(1, AV_CH_LAYOUT_MONO)
395 #define AV_CHANNEL_LAYOUT_STEREO AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO)
396 #define AV_CHANNEL_LAYOUT_2POINT1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2POINT1)
397 #define AV_CHANNEL_LAYOUT_2_1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2_1)
398 #define AV_CHANNEL_LAYOUT_SURROUND AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_SURROUND)
399 #define AV_CHANNEL_LAYOUT_3POINT1 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_3POINT1)
400 #define AV_CHANNEL_LAYOUT_4POINT0 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_4POINT0)
401 #define AV_CHANNEL_LAYOUT_4POINT1 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_4POINT1)
402 #define AV_CHANNEL_LAYOUT_2_2 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_2_2)
403 #define AV_CHANNEL_LAYOUT_QUAD AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_QUAD)
404 #define AV_CHANNEL_LAYOUT_5POINT0 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0)
405 #define AV_CHANNEL_LAYOUT_5POINT1 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1)
406 #define AV_CHANNEL_LAYOUT_5POINT0_BACK AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0_BACK)
407 #define AV_CHANNEL_LAYOUT_5POINT1_BACK AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1_BACK)
408 #define AV_CHANNEL_LAYOUT_6POINT0 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0)
409 #define AV_CHANNEL_LAYOUT_6POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0_FRONT)
410 #define AV_CHANNEL_LAYOUT_3POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_3POINT1POINT2)
411 #define AV_CHANNEL_LAYOUT_HEXAGONAL AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_HEXAGONAL)
412 #define AV_CHANNEL_LAYOUT_6POINT1 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1)
413 #define AV_CHANNEL_LAYOUT_6POINT1_BACK AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_BACK)
414 #define AV_CHANNEL_LAYOUT_6POINT1_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_FRONT)
415 #define AV_CHANNEL_LAYOUT_7POINT0 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0)
416 #define AV_CHANNEL_LAYOUT_7POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0_FRONT)
417 #define AV_CHANNEL_LAYOUT_7POINT1 AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1)
418 #define AV_CHANNEL_LAYOUT_7POINT1_WIDE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE)
419 #define AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE_BACK)
420 #define AV_CHANNEL_LAYOUT_5POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_5POINT1POINT2)
421 #define AV_CHANNEL_LAYOUT_5POINT1POINT2_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_5POINT1POINT2_BACK)
422 #define AV_CHANNEL_LAYOUT_OCTAGONAL AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_OCTAGONAL)
423 #define AV_CHANNEL_LAYOUT_CUBE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_CUBE)
424 #define AV_CHANNEL_LAYOUT_5POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(10, AV_CH_LAYOUT_5POINT1POINT4_BACK)
425 #define AV_CHANNEL_LAYOUT_7POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(10, AV_CH_LAYOUT_7POINT1POINT2)
426 #define AV_CHANNEL_LAYOUT_7POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(12, AV_CH_LAYOUT_7POINT1POINT4_BACK)
427 #define AV_CHANNEL_LAYOUT_7POINT2POINT3 AV_CHANNEL_LAYOUT_MASK(12, AV_CH_LAYOUT_7POINT2POINT3)
428 #define AV_CHANNEL_LAYOUT_9POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(14, AV_CH_LAYOUT_9POINT1POINT4_BACK)
429 #define AV_CHANNEL_LAYOUT_9POINT1POINT6 AV_CHANNEL_LAYOUT_MASK(16, AV_CH_LAYOUT_9POINT1POINT6)
430 #define AV_CHANNEL_LAYOUT_HEXADECAGONAL AV_CHANNEL_LAYOUT_MASK(16, AV_CH_LAYOUT_HEXADECAGONAL)
431 #define AV_CHANNEL_LAYOUT_BINAURAL AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_BINAURAL)
432 #define AV_CHANNEL_LAYOUT_STEREO_DOWNMIX AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO_DOWNMIX)
433 #define AV_CHANNEL_LAYOUT_22POINT2 AV_CHANNEL_LAYOUT_MASK(24, AV_CH_LAYOUT_22POINT2)
434 
435 #define AV_CHANNEL_LAYOUT_7POINT1_TOP_BACK AV_CHANNEL_LAYOUT_5POINT1POINT2_BACK
436 
437 #define AV_CHANNEL_LAYOUT_AMBISONIC_FIRST_ORDER \
438  { /* .order */ AV_CHANNEL_ORDER_AMBISONIC, \
439  /* .nb_channels */ 4, \
440  /* .u.mask */ { 0 }, \
441  /* .opaque */ NULL }
442 /** @} */
443 
444 struct AVBPrint;
445 
446 /**
447  * Get a human readable string in an abbreviated form describing a given channel.
448  * This is the inverse function of @ref av_channel_from_string().
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 name 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_name(char *buf, size_t buf_size, enum AVChannel channel);
458 
459 /**
460  * bprint variant of av_channel_name().
461  *
462  * @note the string will be appended to the bprint buffer.
463  */
464 void av_channel_name_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
465 
466 /**
467  * Get a human readable string describing a given channel.
468  *
469  * @param buf pre-allocated buffer where to put the generated string
470  * @param buf_size size in bytes of the buffer.
471  * @param channel the AVChannel whose description to get
472  * @return amount of bytes needed to hold the output string, or a negative AVERROR
473  * on failure. If the returned value is bigger than buf_size, then the
474  * string was truncated.
475  */
476 int av_channel_description(char *buf, size_t buf_size, enum AVChannel channel);
477 
478 /**
479  * bprint variant of av_channel_description().
480  *
481  * @note the string will be appended to the bprint buffer.
482  */
483 void av_channel_description_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
484 
485 /**
486  * This is the inverse function of @ref av_channel_name().
487  *
488  * @return the channel with the given name
489  * AV_CHAN_NONE when name does not identify a known channel
490  */
491 enum AVChannel av_channel_from_string(const char *name);
492 
493 /**
494  * Initialize a custom channel layout with the specified number of channels.
495  * The channel map will be allocated and the designation of all channels will
496  * be set to AV_CHAN_UNKNOWN.
497  *
498  * This is only a convenience helper function, a custom channel layout can also
499  * be constructed without using this.
500  *
501  * @param channel_layout the layout structure to be initialized
502  * @param nb_channels the number of channels
503  *
504  * @return 0 on success
505  * AVERROR(EINVAL) if the number of channels <= 0
506  * AVERROR(ENOMEM) if the channel map could not be allocated
507  */
508 int av_channel_layout_custom_init(AVChannelLayout *channel_layout, int nb_channels);
509 
510 /**
511  * Initialize a native channel layout from a bitmask indicating which channels
512  * are present.
513  *
514  * @param channel_layout the layout structure to be initialized
515  * @param mask bitmask describing the channel layout
516  *
517  * @return 0 on success
518  * AVERROR(EINVAL) for invalid mask values
519  */
520 int av_channel_layout_from_mask(AVChannelLayout *channel_layout, uint64_t mask);
521 
522 /**
523  * Initialize a channel layout from a given string description.
524  * The input string can be represented by:
525  * - the formal channel layout name (returned by av_channel_layout_describe())
526  * - single or multiple channel names (returned by av_channel_name(), eg. "FL",
527  * or concatenated with "+", each optionally containing a custom name after
528  * a "@", eg. "FL@Left+FR@Right+LFE")
529  * - a decimal or hexadecimal value of a native channel layout (eg. "4" or "0x4")
530  * - the number of channels with default layout (eg. "4c")
531  * - the number of unordered channels (eg. "4C" or "4 channels")
532  * - the ambisonic order followed by optional non-diegetic channels (eg.
533  * "ambisonic 2+stereo")
534  * On error, the channel layout will remain uninitialized, but not necessarily
535  * untouched.
536  *
537  * @param channel_layout uninitialized channel layout for the result
538  * @param str string describing the channel layout
539  * @return 0 on success parsing the channel layout
540  * AVERROR(EINVAL) if an invalid channel layout string was provided
541  * AVERROR(ENOMEM) if there was not enough memory
542  */
544  const char *str);
545 
546 /**
547  * Get the default channel layout for a given number of channels.
548  *
549  * @param ch_layout the layout structure to be initialized
550  * @param nb_channels number of channels
551  */
552 void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels);
553 
554 /**
555  * Iterate over all standard channel layouts.
556  *
557  * @param opaque a pointer where libavutil will store the iteration state. Must
558  * point to NULL to start the iteration.
559  *
560  * @return the standard channel layout or NULL when the iteration is
561  * finished
562  */
563 const AVChannelLayout *av_channel_layout_standard(void **opaque);
564 
565 /**
566  * Free any allocated data in the channel layout and reset the channel
567  * count to 0.
568  *
569  * @param channel_layout the layout structure to be uninitialized
570  */
571 void av_channel_layout_uninit(AVChannelLayout *channel_layout);
572 
573 /**
574  * Make a copy of a channel layout. This differs from just assigning src to dst
575  * in that it allocates and copies the map for AV_CHANNEL_ORDER_CUSTOM.
576  *
577  * @note the destination channel_layout will be always uninitialized before copy.
578  *
579  * @param dst destination channel layout
580  * @param src source channel layout
581  * @return 0 on success, a negative AVERROR on error.
582  */
584 
585 /**
586  * Get a human-readable string describing the channel layout properties.
587  * The string will be in the same format that is accepted by
588  * @ref av_channel_layout_from_string(), allowing to rebuild the same
589  * channel layout, except for opaque pointers.
590  *
591  * @param channel_layout channel layout to be described
592  * @param buf pre-allocated buffer where to put the generated string
593  * @param buf_size size in bytes of the buffer.
594  * @return amount of bytes needed to hold the output string, or a negative AVERROR
595  * on failure. If the returned value is bigger than buf_size, then the
596  * string was truncated.
597  */
598 int av_channel_layout_describe(const AVChannelLayout *channel_layout,
599  char *buf, size_t buf_size);
600 
601 /**
602  * bprint variant of av_channel_layout_describe().
603  *
604  * @note the string will be appended to the bprint buffer.
605  * @return 0 on success, or a negative AVERROR value on failure.
606  */
607 int av_channel_layout_describe_bprint(const AVChannelLayout *channel_layout,
608  struct AVBPrint *bp);
609 
610 /**
611  * Get the channel with the given index in a channel layout.
612  *
613  * @param channel_layout input channel layout
614  * @param idx index of the channel
615  * @return channel with the index idx in channel_layout on success or
616  * AV_CHAN_NONE on failure (if idx is not valid or the channel order is
617  * unspecified)
618  */
619 enum AVChannel
620 av_channel_layout_channel_from_index(const AVChannelLayout *channel_layout, unsigned int idx);
621 
622 /**
623  * Get the index of a given channel in a channel layout. In case multiple
624  * channels are found, only the first match will be returned.
625  *
626  * @param channel_layout input channel layout
627  * @param channel the channel whose index to obtain
628  * @return index of channel in channel_layout on success or a negative number if
629  * channel is not present in channel_layout.
630  */
631 int av_channel_layout_index_from_channel(const AVChannelLayout *channel_layout,
632  enum AVChannel channel);
633 
634 /**
635  * Get the index in a channel layout of a channel described by the given string.
636  * In case multiple channels are found, only the first match will be returned.
637  *
638  * This function accepts channel names in the same format as
639  * @ref av_channel_from_string().
640  *
641  * @param channel_layout input channel layout
642  * @param name string describing the channel whose index to obtain
643  * @return a channel index described by the given string, or a negative AVERROR
644  * value.
645  */
646 int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout,
647  const char *name);
648 
649 /**
650  * Get a channel described by the given string.
651  *
652  * This function accepts channel names in the same format as
653  * @ref av_channel_from_string().
654  *
655  * @param channel_layout input channel layout
656  * @param name string describing the channel to obtain
657  * @return a channel described by the given string in channel_layout on success
658  * or AV_CHAN_NONE on failure (if the string is not valid or the channel
659  * order is unspecified)
660  */
661 enum AVChannel
663  const char *name);
664 
665 /**
666  * Find out what channels from a given set are present in a channel layout,
667  * without regard for their positions.
668  *
669  * @param channel_layout input channel layout
670  * @param mask a combination of AV_CH_* representing a set of channels
671  * @return a bitfield representing all the channels from mask that are present
672  * in channel_layout
673  */
674 uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout,
675  uint64_t mask);
676 
677 /**
678  * Check whether a channel layout is valid, i.e. can possibly describe audio
679  * data.
680  *
681  * @param channel_layout input channel layout
682  * @return 1 if channel_layout is valid, 0 otherwise.
683  */
684 int av_channel_layout_check(const AVChannelLayout *channel_layout);
685 
686 /**
687  * Check whether two channel layouts are semantically the same, i.e. the same
688  * channels are present on the same positions in both.
689  *
690  * If one of the channel layouts is AV_CHANNEL_ORDER_UNSPEC, while the other is
691  * not, they are considered to be unequal. If both are AV_CHANNEL_ORDER_UNSPEC,
692  * they are considered equal iff the channel counts are the same in both.
693  *
694  * @param chl input channel layout
695  * @param chl1 input channel layout
696  * @return 0 if chl and chl1 are equal, 1 if they are not equal. A negative
697  * AVERROR code if one or both are invalid.
698  */
699 int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1);
700 
701 /**
702  * Return the order if the layout is n-th order standard-order ambisonic.
703  * The presence of optional extra non-diegetic channels at the end is not taken
704  * into account.
705  *
706  * @param channel_layout input channel layout
707  * @return the order of the layout, a negative error code otherwise.
708  */
709 int av_channel_layout_ambisonic_order(const AVChannelLayout *channel_layout);
710 
711 /**
712  * The conversion must be lossless.
713  */
714 #define AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS (1 << 0)
715 
716 /**
717  * The specified retype target order is ignored and the simplest possible
718  * (canonical) order is used for which the input layout can be losslessy
719  * represented.
720  */
721 #define AV_CHANNEL_LAYOUT_RETYPE_FLAG_CANONICAL (1 << 1)
722 
723 /**
724  * Change the AVChannelOrder of a channel layout.
725  *
726  * Change of AVChannelOrder can be either lossless or lossy. In case of a
727  * lossless conversion all the channel designations and the associated channel
728  * names (if any) are kept. On a lossy conversion the channel names and channel
729  * designations might be lost depending on the capabilities of the desired
730  * AVChannelOrder. Note that some conversions are simply not possible in which
731  * case this function returns AVERROR(ENOSYS).
732  *
733  * The following conversions are supported:
734  *
735  * Any -> Custom : Always possible, always lossless.
736  * Any -> Unspecified: Always possible, lossless if channel designations
737  * are all unknown and channel names are not used, lossy otherwise.
738  * Custom -> Ambisonic : Possible if it contains ambisonic channels with
739  * optional non-diegetic channels in the end. Lossy if the channels have
740  * custom names, lossless otherwise.
741  * Custom -> Native : Possible if it contains native channels in native
742  * order. Lossy if the channels have custom names, lossless otherwise.
743  *
744  * On error this function keeps the original channel layout untouched.
745  *
746  * @param channel_layout channel layout which will be changed
747  * @param order the desired channel layout order
748  * @param flags a combination of AV_CHANNEL_LAYOUT_RETYPE_FLAG_* constants
749  * @return 0 if the conversion was successful and lossless or if the channel
750  * layout was already in the desired order
751  * >0 if the conversion was successful but lossy
752  * AVERROR(ENOSYS) if the conversion was not possible (or would be
753  * lossy and AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS was specified)
754  * AVERROR(EINVAL), AVERROR(ENOMEM) on error
755  */
756 int av_channel_layout_retype(AVChannelLayout *channel_layout, enum AVChannelOrder order, int flags);
757 
758 /**
759  * @}
760  */
761 
762 #endif /* AVUTIL_CHANNEL_LAYOUT_H */
AVChannelOrder
AVChannelOrder
Definition: channel_layout.h:114
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:159
AV_CHAN_BINAURAL_RIGHT
@ AV_CHAN_BINAURAL_RIGHT
Definition: channel_layout.h:88
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:370
mask
int mask
Definition: mediacodecdec_common.c:154
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:485
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:673
AVChannelLayout::order
enum AVChannelOrder order
Channel order used in this layout.
Definition: channel_layout.h:324
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:351
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:329
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:599
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:119
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:262
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:653
AVChannelCustom
An AVChannelCustom defines a single channel within a custom order layout.
Definition: channel_layout.h:283
AV_MATRIX_ENCODING_NB
@ AV_MATRIX_ENCODING_NB
Definition: channel_layout.h:268
AV_CHAN_UNKNOWN
@ AV_CHAN_UNKNOWN
Channel contains data, but its position is unknown.
Definition: channel_layout.h:94
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:119
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:252
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:747
av_channel_layout_standard
const AVChannelLayout * av_channel_layout_standard(void **opaque)
Iterate over all standard channel layouts.
Definition: channel_layout.c:852
AV_MATRIX_ENCODING_DPLIIX
@ AV_MATRIX_ENCODING_DPLIIX
Definition: channel_layout.h:264
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:260
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:267
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:155
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:319
dst
uint8_t ptrdiff_t const uint8_t ptrdiff_t int intptr_t intptr_t int int16_t * dst
Definition: dsp.h:83
AV_MATRIX_ENCODING_NONE
@ AV_MATRIX_ENCODING_NONE
Definition: channel_layout.h:261
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:111
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:137
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:885
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:125
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:91
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:809
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:232
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:839
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:312
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:104
AVChannelCustom::name
char name[16]
Definition: channel_layout.h:285
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:783
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:152
AV_CHAN_BINAURAL_LEFT
@ AV_CHAN_BINAURAL_LEFT
Definition: channel_layout.h:87
AV_CHAN_NONE
@ AV_CHAN_NONE
Invalid channel index.
Definition: channel_layout.h:49
AVChannelCustom::opaque
void * opaque
Definition: channel_layout.h:286
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:132
AVChannelLayout::opaque
void * opaque
For some private data of the user.
Definition: channel_layout.h:376
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:865
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:266
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:702
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:713
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:442
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:449
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
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:265
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:108
AVChannelLayout::u
union AVChannelLayout::@434 u
Details about which channels are present in this layout.
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:482
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:86
AVChannelCustom::id
enum AVChannel id
Definition: channel_layout.h:284
src
#define src
Definition: vp8dsp.c:248
channel
channel
Definition: ebur128.h:39
AV_MATRIX_ENCODING_DPLII
@ AV_MATRIX_ENCODING_DPLII
Definition: channel_layout.h:263