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
47enum AVChannel {
48 ///< Invalid channel index
49 AV_CHAN_NONE = -1,
50 AV_CHAN_FRONT_LEFT,
51 AV_CHAN_FRONT_RIGHT,
52 AV_CHAN_FRONT_CENTER,
53 AV_CHAN_LOW_FREQUENCY,
54 AV_CHAN_BACK_LEFT,
55 AV_CHAN_BACK_RIGHT,
56 AV_CHAN_FRONT_LEFT_OF_CENTER,
57 AV_CHAN_FRONT_RIGHT_OF_CENTER,
58 AV_CHAN_BACK_CENTER,
59 AV_CHAN_SIDE_LEFT,
60 AV_CHAN_SIDE_RIGHT,
61 AV_CHAN_TOP_CENTER,
62 AV_CHAN_TOP_FRONT_LEFT,
63 AV_CHAN_TOP_FRONT_CENTER,
64 AV_CHAN_TOP_FRONT_RIGHT,
65 AV_CHAN_TOP_BACK_LEFT,
66 AV_CHAN_TOP_BACK_CENTER,
67 AV_CHAN_TOP_BACK_RIGHT,
68 /** Stereo downmix. */
69 AV_CHAN_STEREO_LEFT = 29,
70 /** See above. */
71 AV_CHAN_STEREO_RIGHT,
72 AV_CHAN_WIDE_LEFT,
73 AV_CHAN_WIDE_RIGHT,
74 AV_CHAN_SURROUND_DIRECT_LEFT,
75 AV_CHAN_SURROUND_DIRECT_RIGHT,
76 AV_CHAN_LOW_FREQUENCY_2,
77 AV_CHAN_TOP_SIDE_LEFT,
78 AV_CHAN_TOP_SIDE_RIGHT,
79 AV_CHAN_BOTTOM_FRONT_CENTER,
80 AV_CHAN_BOTTOM_FRONT_LEFT,
81 AV_CHAN_BOTTOM_FRONT_RIGHT,
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 */
101 AV_CHAN_AMBISONIC_BASE = 0x400,
102 // leave space for 1024 ids, which correspond to maximum order-32 harmonics,
103 // which should be enough for the foreseeable use cases
104 AV_CHAN_AMBISONIC_END = 0x7ff,
105};
106
107enum AVChannelOrder {
108 /**
109 * Only the channel count is specified, without any further information
110 * about the channel order.
111 */
112 AV_CHANNEL_ORDER_UNSPEC,
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 */
118 AV_CHANNEL_ORDER_NATIVE,
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_SILENCE)
123 * channels at arbitrary positions.
124 */
125 AV_CHANNEL_ORDER_CUSTOM,
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 */
148 AV_CHANNEL_ORDER_AMBISONIC,
149};
150
151
152/**
153 * @defgroup channel_masks Audio channel masks
154 *
155 * A channel layout is a 64-bits integer with a bit set for every channel.
156 * The number of bits set must be equal to the number of channels.
157 * The value 0 means that the channel layout is not known.
158 * @note this data structure is not powerful enough to handle channels
159 * combinations that have the same channel multiple times, such as
160 * dual-mono.
161 *
162 * @{
163 */
164#define AV_CH_FRONT_LEFT (1ULL << AV_CHAN_FRONT_LEFT )
165#define AV_CH_FRONT_RIGHT (1ULL << AV_CHAN_FRONT_RIGHT )
166#define AV_CH_FRONT_CENTER (1ULL << AV_CHAN_FRONT_CENTER )
167#define AV_CH_LOW_FREQUENCY (1ULL << AV_CHAN_LOW_FREQUENCY )
168#define AV_CH_BACK_LEFT (1ULL << AV_CHAN_BACK_LEFT )
169#define AV_CH_BACK_RIGHT (1ULL << AV_CHAN_BACK_RIGHT )
170#define AV_CH_FRONT_LEFT_OF_CENTER (1ULL << AV_CHAN_FRONT_LEFT_OF_CENTER )
171#define AV_CH_FRONT_RIGHT_OF_CENTER (1ULL << AV_CHAN_FRONT_RIGHT_OF_CENTER)
172#define AV_CH_BACK_CENTER (1ULL << AV_CHAN_BACK_CENTER )
173#define AV_CH_SIDE_LEFT (1ULL << AV_CHAN_SIDE_LEFT )
174#define AV_CH_SIDE_RIGHT (1ULL << AV_CHAN_SIDE_RIGHT )
175#define AV_CH_TOP_CENTER (1ULL << AV_CHAN_TOP_CENTER )
176#define AV_CH_TOP_FRONT_LEFT (1ULL << AV_CHAN_TOP_FRONT_LEFT )
177#define AV_CH_TOP_FRONT_CENTER (1ULL << AV_CHAN_TOP_FRONT_CENTER )
178#define AV_CH_TOP_FRONT_RIGHT (1ULL << AV_CHAN_TOP_FRONT_RIGHT )
179#define AV_CH_TOP_BACK_LEFT (1ULL << AV_CHAN_TOP_BACK_LEFT )
180#define AV_CH_TOP_BACK_CENTER (1ULL << AV_CHAN_TOP_BACK_CENTER )
181#define AV_CH_TOP_BACK_RIGHT (1ULL << AV_CHAN_TOP_BACK_RIGHT )
182#define AV_CH_STEREO_LEFT (1ULL << AV_CHAN_STEREO_LEFT )
183#define AV_CH_STEREO_RIGHT (1ULL << AV_CHAN_STEREO_RIGHT )
184#define AV_CH_WIDE_LEFT (1ULL << AV_CHAN_WIDE_LEFT )
185#define AV_CH_WIDE_RIGHT (1ULL << AV_CHAN_WIDE_RIGHT )
186#define AV_CH_SURROUND_DIRECT_LEFT (1ULL << AV_CHAN_SURROUND_DIRECT_LEFT )
187#define AV_CH_SURROUND_DIRECT_RIGHT (1ULL << AV_CHAN_SURROUND_DIRECT_RIGHT)
188#define AV_CH_LOW_FREQUENCY_2 (1ULL << AV_CHAN_LOW_FREQUENCY_2 )
189#define AV_CH_TOP_SIDE_LEFT (1ULL << AV_CHAN_TOP_SIDE_LEFT )
190#define AV_CH_TOP_SIDE_RIGHT (1ULL << AV_CHAN_TOP_SIDE_RIGHT )
191#define AV_CH_BOTTOM_FRONT_CENTER (1ULL << AV_CHAN_BOTTOM_FRONT_CENTER )
192#define AV_CH_BOTTOM_FRONT_LEFT (1ULL << AV_CHAN_BOTTOM_FRONT_LEFT )
193#define AV_CH_BOTTOM_FRONT_RIGHT (1ULL << AV_CHAN_BOTTOM_FRONT_RIGHT )
194
195#if FF_API_OLD_CHANNEL_LAYOUT
196/** Channel mask value used for AVCodecContext.request_channel_layout
197 to indicate that the user requests the channel order of the decoder output
198 to be the native codec channel order.
199 @deprecated channel order is now indicated in a special field in
200 AVChannelLayout
201 */
202#define AV_CH_LAYOUT_NATIVE 0x8000000000000000ULL
203#endif
204
205/**
206 * @}
207 * @defgroup channel_mask_c Audio channel layouts
208 * @{
209 * */
210#define AV_CH_LAYOUT_MONO (AV_CH_FRONT_CENTER)
211#define AV_CH_LAYOUT_STEREO (AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT)
212#define AV_CH_LAYOUT_2POINT1 (AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY)
213#define AV_CH_LAYOUT_2_1 (AV_CH_LAYOUT_STEREO|AV_CH_BACK_CENTER)
214#define AV_CH_LAYOUT_SURROUND (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER)
215#define AV_CH_LAYOUT_3POINT1 (AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY)
216#define AV_CH_LAYOUT_4POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_CENTER)
217#define AV_CH_LAYOUT_4POINT1 (AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY)
218#define AV_CH_LAYOUT_2_2 (AV_CH_LAYOUT_STEREO|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
219#define AV_CH_LAYOUT_QUAD (AV_CH_LAYOUT_STEREO|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
220#define AV_CH_LAYOUT_5POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
221#define AV_CH_LAYOUT_5POINT1 (AV_CH_LAYOUT_5POINT0|AV_CH_LOW_FREQUENCY)
222#define AV_CH_LAYOUT_5POINT0_BACK (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
223#define AV_CH_LAYOUT_5POINT1_BACK (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_LOW_FREQUENCY)
224#define AV_CH_LAYOUT_6POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_CENTER)
225#define AV_CH_LAYOUT_6POINT0_FRONT (AV_CH_LAYOUT_2_2|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
226#define AV_CH_LAYOUT_HEXAGONAL (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_BACK_CENTER)
227#define AV_CH_LAYOUT_3POINT1POINT2 (AV_CH_LAYOUT_3POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
228#define AV_CH_LAYOUT_6POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_CENTER)
229#define AV_CH_LAYOUT_6POINT1_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER)
230#define AV_CH_LAYOUT_6POINT1_FRONT (AV_CH_LAYOUT_6POINT0_FRONT|AV_CH_LOW_FREQUENCY)
231#define AV_CH_LAYOUT_7POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
232#define AV_CH_LAYOUT_7POINT0_FRONT (AV_CH_LAYOUT_5POINT0|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
233#define AV_CH_LAYOUT_7POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT)
234#define AV_CH_LAYOUT_7POINT1_WIDE (AV_CH_LAYOUT_5POINT1|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
235#define AV_CH_LAYOUT_7POINT1_WIDE_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER)
236#define AV_CH_LAYOUT_5POINT1POINT2_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
237#define AV_CH_LAYOUT_OCTAGONAL (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_CENTER|AV_CH_BACK_RIGHT)
238#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)
239#define AV_CH_LAYOUT_5POINT1POINT4_BACK (AV_CH_LAYOUT_5POINT1POINT2_BACK|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT)
240#define AV_CH_LAYOUT_7POINT1POINT2 (AV_CH_LAYOUT_7POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT)
241#define AV_CH_LAYOUT_7POINT1POINT4_BACK (AV_CH_LAYOUT_7POINT1POINT2|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT)
242#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)
243#define AV_CH_LAYOUT_STEREO_DOWNMIX (AV_CH_STEREO_LEFT|AV_CH_STEREO_RIGHT)
244#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)
245
246#define AV_CH_LAYOUT_7POINT1_TOP_BACK AV_CH_LAYOUT_5POINT1POINT2_BACK
247
248enum AVMatrixEncoding {
249 AV_MATRIX_ENCODING_NONE,
250 AV_MATRIX_ENCODING_DOLBY,
251 AV_MATRIX_ENCODING_DPLII,
252 AV_MATRIX_ENCODING_DPLIIX,
253 AV_MATRIX_ENCODING_DPLIIZ,
254 AV_MATRIX_ENCODING_DOLBYEX,
255 AV_MATRIX_ENCODING_DOLBYHEADPHONE,
256 AV_MATRIX_ENCODING_NB
257};
258
259/**
260 * @}
261 */
262
263/**
264 * An AVChannelCustom defines a single channel within a custom order layout
265 *
266 * Unlike most structures in FFmpeg, sizeof(AVChannelCustom) is a part of the
267 * public ABI.
268 *
269 * No new fields may be added to it without a major version bump.
270 */
271typedef struct AVChannelCustom {
272 enum AVChannel id;
273 char name[16];
274 void *opaque;
275} AVChannelCustom;
276
277/**
278 * An AVChannelLayout holds information about the channel layout of audio data.
279 *
280 * A channel layout here is defined as a set of channels ordered in a specific
281 * way (unless the channel order is AV_CHANNEL_ORDER_UNSPEC, in which case an
282 * AVChannelLayout carries only the channel count).
283 * All orders may be treated as if they were AV_CHANNEL_ORDER_UNSPEC by
284 * ignoring everything but the channel count, as long as av_channel_layout_check()
285 * considers they are valid.
286 *
287 * Unlike most structures in FFmpeg, sizeof(AVChannelLayout) is a part of the
288 * public ABI and may be used by the caller. E.g. it may be allocated on stack
289 * or embedded in caller-defined structs.
290 *
291 * AVChannelLayout can be initialized as follows:
292 * - default initialization with {0}, followed by setting all used fields
293 * correctly;
294 * - by assigning one of the predefined AV_CHANNEL_LAYOUT_* initializers;
295 * - with a constructor function, such as av_channel_layout_default(),
296 * av_channel_layout_from_mask() or av_channel_layout_from_string().
297 *
298 * The channel layout must be unitialized with av_channel_layout_uninit()
299 *
300 * Copying an AVChannelLayout via assigning is forbidden,
301 * av_channel_layout_copy() must be used instead (and its return value should
302 * be checked)
303 *
304 * No new fields may be added to it without a major version bump, except for
305 * new elements of the union fitting in sizeof(uint64_t).
306 */
307typedef struct AVChannelLayout {
308 /**
309 * Channel order used in this layout.
310 * This is a mandatory field.
311 */
312 enum AVChannelOrder order;
313
314 /**
315 * Number of channels in this layout. Mandatory field.
316 */
317 int nb_channels;
318
319 /**
320 * Details about which channels are present in this layout.
321 * For AV_CHANNEL_ORDER_UNSPEC, this field is undefined and must not be
322 * used.
323 */
324 union {
325 /**
326 * This member must be used for AV_CHANNEL_ORDER_NATIVE, and may be used
327 * for AV_CHANNEL_ORDER_AMBISONIC to signal non-diegetic channels.
328 * It is a bitmask, where the position of each set bit means that the
329 * AVChannel with the corresponding value is present.
330 *
331 * I.e. when (mask & (1 << AV_CHAN_FOO)) is non-zero, then AV_CHAN_FOO
332 * is present in the layout. Otherwise it is not present.
333 *
334 * @note when a channel layout using a bitmask is constructed or
335 * modified manually (i.e. not using any of the av_channel_layout_*
336 * functions), the code doing it must ensure that the number of set bits
337 * is equal to nb_channels.
338 */
339 uint64_t mask;
340 /**
341 * This member must be used when the channel order is
342 * AV_CHANNEL_ORDER_CUSTOM. It is a nb_channels-sized array, with each
343 * element signalling the presence of the AVChannel with the
344 * corresponding value in map[i].id.
345 *
346 * I.e. when map[i].id is equal to AV_CHAN_FOO, then AV_CH_FOO is the
347 * i-th channel in the audio data.
348 *
349 * When map[i].id is in the range between AV_CHAN_AMBISONIC_BASE and
350 * AV_CHAN_AMBISONIC_END (inclusive), the channel contains an ambisonic
351 * component with ACN index (as defined above)
352 * n = map[i].id - AV_CHAN_AMBISONIC_BASE.
353 *
354 * map[i].name may be filled with a 0-terminated string, in which case
355 * it will be used for the purpose of identifying the channel with the
356 * convenience functions below. Otherise it must be zeroed.
357 */
358 AVChannelCustom *map;
359 } u;
360
361 /**
362 * For some private data of the user.
363 */
364 void *opaque;
365} AVChannelLayout;
366
367/**
368 * Macro to define native channel layouts
369 *
370 * @note This doesn't use designated initializers for compatibility with C++ 17 and older.
371 */
372#define AV_CHANNEL_LAYOUT_MASK(nb, m) \
373 { /* .order */ AV_CHANNEL_ORDER_NATIVE, \
374 /* .nb_channels */ (nb), \
375 /* .u.mask */ { m }, \
376 /* .opaque */ NULL }
377
378/**
379 * @name Common pre-defined channel layouts
380 * @{
381 */
382#define AV_CHANNEL_LAYOUT_MONO AV_CHANNEL_LAYOUT_MASK(1, AV_CH_LAYOUT_MONO)
383#define AV_CHANNEL_LAYOUT_STEREO AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO)
384#define AV_CHANNEL_LAYOUT_2POINT1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2POINT1)
385#define AV_CHANNEL_LAYOUT_2_1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2_1)
386#define AV_CHANNEL_LAYOUT_SURROUND AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_SURROUND)
387#define AV_CHANNEL_LAYOUT_3POINT1 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_3POINT1)
388#define AV_CHANNEL_LAYOUT_4POINT0 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_4POINT0)
389#define AV_CHANNEL_LAYOUT_4POINT1 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_4POINT1)
390#define AV_CHANNEL_LAYOUT_2_2 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_2_2)
391#define AV_CHANNEL_LAYOUT_QUAD AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_QUAD)
392#define AV_CHANNEL_LAYOUT_5POINT0 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0)
393#define AV_CHANNEL_LAYOUT_5POINT1 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1)
394#define AV_CHANNEL_LAYOUT_5POINT0_BACK AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0_BACK)
395#define AV_CHANNEL_LAYOUT_5POINT1_BACK AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1_BACK)
396#define AV_CHANNEL_LAYOUT_6POINT0 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0)
397#define AV_CHANNEL_LAYOUT_6POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0_FRONT)
398#define AV_CHANNEL_LAYOUT_3POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_3POINT1POINT2)
399#define AV_CHANNEL_LAYOUT_HEXAGONAL AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_HEXAGONAL)
400#define AV_CHANNEL_LAYOUT_6POINT1 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1)
401#define AV_CHANNEL_LAYOUT_6POINT1_BACK AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_BACK)
402#define AV_CHANNEL_LAYOUT_6POINT1_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_FRONT)
403#define AV_CHANNEL_LAYOUT_7POINT0 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0)
404#define AV_CHANNEL_LAYOUT_7POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0_FRONT)
405#define AV_CHANNEL_LAYOUT_7POINT1 AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1)
406#define AV_CHANNEL_LAYOUT_7POINT1_WIDE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE)
407#define AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE_BACK)
408#define AV_CHANNEL_LAYOUT_5POINT1POINT2_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_5POINT1POINT2_BACK)
409#define AV_CHANNEL_LAYOUT_OCTAGONAL AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_OCTAGONAL)
410#define AV_CHANNEL_LAYOUT_CUBE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_CUBE)
411#define AV_CHANNEL_LAYOUT_5POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(10, AV_CH_LAYOUT_5POINT1POINT4_BACK)
412#define AV_CHANNEL_LAYOUT_7POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(10, AV_CH_LAYOUT_7POINT1POINT2)
413#define AV_CHANNEL_LAYOUT_7POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(12, AV_CH_LAYOUT_7POINT1POINT4_BACK)
414#define AV_CHANNEL_LAYOUT_HEXADECAGONAL AV_CHANNEL_LAYOUT_MASK(16, AV_CH_LAYOUT_HEXADECAGONAL)
415#define AV_CHANNEL_LAYOUT_STEREO_DOWNMIX AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO_DOWNMIX)
416#define AV_CHANNEL_LAYOUT_22POINT2 AV_CHANNEL_LAYOUT_MASK(24, AV_CH_LAYOUT_22POINT2)
417
418#define AV_CHANNEL_LAYOUT_7POINT1_TOP_BACK AV_CHANNEL_LAYOUT_5POINT1POINT2_BACK
419
420#define AV_CHANNEL_LAYOUT_AMBISONIC_FIRST_ORDER \
421 { /* .order */ AV_CHANNEL_ORDER_AMBISONIC, \
422 /* .nb_channels */ 4, \
423 /* .u.mask */ { 0 }, \
424 /* .opaque */ NULL }
425/** @} */
426
427struct AVBPrint;
428
429#if FF_API_OLD_CHANNEL_LAYOUT
430/**
431 * @name Deprecated Functions
432 * @{
433 */
434
435/**
436 * Return a channel layout id that matches name, or 0 if no match is found.
437 *
438 * name can be one or several of the following notations,
439 * separated by '+' or '|':
440 * - the name of an usual channel layout (mono, stereo, 4.0, quad, 5.0,
441 * 5.0(side), 5.1, 5.1(side), 7.1, 7.1(wide), downmix);
442 * - the name of a single channel (FL, FR, FC, LFE, BL, BR, FLC, FRC, BC,
443 * SL, SR, TC, TFL, TFC, TFR, TBL, TBC, TBR, DL, DR);
444 * - a number of channels, in decimal, followed by 'c', yielding
445 * the default channel layout for that number of channels (@see
446 * av_get_default_channel_layout);
447 * - a channel layout mask, in hexadecimal starting with "0x" (see the
448 * AV_CH_* macros).
449 *
450 * Example: "stereo+FC" = "2c+FC" = "2c+1c" = "0x7"
451 *
452 * @deprecated use av_channel_layout_from_string()
453 */
454attribute_deprecated
455uint64_t av_get_channel_layout(const char *name);
456
457/**
458 * Return a channel layout and the number of channels based on the specified name.
459 *
460 * This function is similar to (@see av_get_channel_layout), but can also parse
461 * unknown channel layout specifications.
462 *
463 * @param[in] name channel layout specification string
464 * @param[out] channel_layout parsed channel layout (0 if unknown)
465 * @param[out] nb_channels number of channels
466 *
467 * @return 0 on success, AVERROR(EINVAL) if the parsing fails.
468 * @deprecated use av_channel_layout_from_string()
469 */
470attribute_deprecated
471int av_get_extended_channel_layout(const char *name, uint64_t* channel_layout, int* nb_channels);
472
473/**
474 * Return a description of a channel layout.
475 * If nb_channels is <= 0, it is guessed from the channel_layout.
476 *
477 * @param buf put here the string containing the channel layout
478 * @param buf_size size in bytes of the buffer
479 * @param nb_channels number of channels
480 * @param channel_layout channel layout bitset
481 * @deprecated use av_channel_layout_describe()
482 */
483attribute_deprecated
484void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, uint64_t channel_layout);
485
486/**
487 * Append a description of a channel layout to a bprint buffer.
488 * @deprecated use av_channel_layout_describe()
489 */
490attribute_deprecated
491void av_bprint_channel_layout(struct AVBPrint *bp, int nb_channels, uint64_t channel_layout);
492
493/**
494 * Return the number of channels in the channel layout.
495 * @deprecated use AVChannelLayout.nb_channels
496 */
497attribute_deprecated
498int av_get_channel_layout_nb_channels(uint64_t channel_layout);
499
500/**
501 * Return default channel layout for a given number of channels.
502 *
503 * @deprecated use av_channel_layout_default()
504 */
505attribute_deprecated
506int64_t av_get_default_channel_layout(int nb_channels);
507
508/**
509 * Get the index of a channel in channel_layout.
510 *
511 * @param channel_layout channel layout bitset
512 * @param channel a channel layout describing exactly one channel which must be
513 * present in channel_layout.
514 *
515 * @return index of channel in channel_layout on success, a negative AVERROR
516 * on error.
517 *
518 * @deprecated use av_channel_layout_index_from_channel()
519 */
520attribute_deprecated
521int av_get_channel_layout_channel_index(uint64_t channel_layout,
522 uint64_t channel);
523
524/**
525 * Get the channel with the given index in channel_layout.
526 * @deprecated use av_channel_layout_channel_from_index()
527 */
528attribute_deprecated
529uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index);
530
531/**
532 * Get the name of a given channel.
533 *
534 * @return channel name on success, NULL on error.
535 *
536 * @deprecated use av_channel_name()
537 */
538attribute_deprecated
539const char *av_get_channel_name(uint64_t channel);
540
541/**
542 * Get the description of a given channel.
543 *
544 * @param channel a channel layout with a single channel
545 * @return channel description on success, NULL on error
546 * @deprecated use av_channel_description()
547 */
548attribute_deprecated
549const char *av_get_channel_description(uint64_t channel);
550
551/**
552 * Get the value and name of a standard channel layout.
553 *
554 * @param[in] index index in an internal list, starting at 0
555 * @param[out] layout channel layout mask
556 * @param[out] name name of the layout
557 * @return 0 if the layout exists,
558 * <0 if index is beyond the limits
559 * @deprecated use av_channel_layout_standard()
560 */
561attribute_deprecated
562int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
563 const char **name);
564/**
565 * @}
566 */
567#endif
568
569/**
570 * Get a human readable string in an abbreviated form describing a given channel.
571 * This is the inverse function of @ref av_channel_from_string().
572 *
573 * @param buf pre-allocated buffer where to put the generated string
574 * @param buf_size size in bytes of the buffer.
575 * @param channel the AVChannel whose name to get
576 * @return amount of bytes needed to hold the output string, or a negative AVERROR
577 * on failure. If the returned value is bigger than buf_size, then the
578 * string was truncated.
579 */
580int av_channel_name(char *buf, size_t buf_size, enum AVChannel channel);
581
582/**
583 * bprint variant of av_channel_name().
584 *
585 * @note the string will be appended to the bprint buffer.
586 */
587void av_channel_name_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
588
589/**
590 * Get a human readable string describing a given channel.
591 *
592 * @param buf pre-allocated buffer where to put the generated string
593 * @param buf_size size in bytes of the buffer.
594 * @param channel the AVChannel whose description to get
595 * @return amount of bytes needed to hold the output string, or a negative AVERROR
596 * on failure. If the returned value is bigger than buf_size, then the
597 * string was truncated.
598 */
599int av_channel_description(char *buf, size_t buf_size, enum AVChannel channel);
600
601/**
602 * bprint variant of av_channel_description().
603 *
604 * @note the string will be appended to the bprint buffer.
605 */
606void av_channel_description_bprint(struct AVBPrint *bp, enum AVChannel channel_id);
607
608/**
609 * This is the inverse function of @ref av_channel_name().
610 *
611 * @return the channel with the given name
612 * AV_CHAN_NONE when name does not identify a known channel
613 */
614enum AVChannel av_channel_from_string(const char *name);
615
616/**
617 * Initialize a native channel layout from a bitmask indicating which channels
618 * are present.
619 *
620 * @param channel_layout the layout structure to be initialized
621 * @param mask bitmask describing the channel layout
622 *
623 * @return 0 on success
624 * AVERROR(EINVAL) for invalid mask values
625 */
626int av_channel_layout_from_mask(AVChannelLayout *channel_layout, uint64_t mask);
627
628/**
629 * Initialize a channel layout from a given string description.
630 * The input string can be represented by:
631 * - the formal channel layout name (returned by av_channel_layout_describe())
632 * - single or multiple channel names (returned by av_channel_name(), eg. "FL",
633 * or concatenated with "+", each optionally containing a custom name after
634 * a "@", eg. "FL@Left+FR@Right+LFE")
635 * - a decimal or hexadecimal value of a native channel layout (eg. "4" or "0x4")
636 * - the number of channels with default layout (eg. "4c")
637 * - the number of unordered channels (eg. "4C" or "4 channels")
638 * - the ambisonic order followed by optional non-diegetic channels (eg.
639 * "ambisonic 2+stereo")
640 *
641 * @param channel_layout input channel layout
642 * @param str string describing the channel layout
643 * @return 0 channel layout was detected, AVERROR_INVALIDATATA otherwise
644 */
645int av_channel_layout_from_string(AVChannelLayout *channel_layout,
646 const char *str);
647
648/**
649 * Get the default channel layout for a given number of channels.
650 *
651 * @param ch_layout the layout structure to be initialized
652 * @param nb_channels number of channels
653 */
654void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels);
655
656/**
657 * Iterate over all standard channel layouts.
658 *
659 * @param opaque a pointer where libavutil will store the iteration state. Must
660 * point to NULL to start the iteration.
661 *
662 * @return the standard channel layout or NULL when the iteration is
663 * finished
664 */
665const AVChannelLayout *av_channel_layout_standard(void **opaque);
666
667/**
668 * Free any allocated data in the channel layout and reset the channel
669 * count to 0.
670 *
671 * @param channel_layout the layout structure to be uninitialized
672 */
673void av_channel_layout_uninit(AVChannelLayout *channel_layout);
674
675/**
676 * Make a copy of a channel layout. This differs from just assigning src to dst
677 * in that it allocates and copies the map for AV_CHANNEL_ORDER_CUSTOM.
678 *
679 * @note the destination channel_layout will be always uninitialized before copy.
680 *
681 * @param dst destination channel layout
682 * @param src source channel layout
683 * @return 0 on success, a negative AVERROR on error.
684 */
685int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src);
686
687/**
688 * Get a human-readable string describing the channel layout properties.
689 * The string will be in the same format that is accepted by
690 * @ref av_channel_layout_from_string(), allowing to rebuild the same
691 * channel layout, except for opaque pointers.
692 *
693 * @param channel_layout channel layout to be described
694 * @param buf pre-allocated buffer where to put the generated string
695 * @param buf_size size in bytes of the buffer.
696 * @return amount of bytes needed to hold the output string, or a negative AVERROR
697 * on failure. If the returned value is bigger than buf_size, then the
698 * string was truncated.
699 */
700int av_channel_layout_describe(const AVChannelLayout *channel_layout,
701 char *buf, size_t buf_size);
702
703/**
704 * bprint variant of av_channel_layout_describe().
705 *
706 * @note the string will be appended to the bprint buffer.
707 * @return 0 on success, or a negative AVERROR value on failure.
708 */
709int av_channel_layout_describe_bprint(const AVChannelLayout *channel_layout,
710 struct AVBPrint *bp);
711
712/**
713 * Get the channel with the given index in a channel layout.
714 *
715 * @param channel_layout input channel layout
716 * @param idx index of the channel
717 * @return channel with the index idx in channel_layout on success or
718 * AV_CHAN_NONE on failure (if idx is not valid or the channel order is
719 * unspecified)
720 */
721enum AVChannel
722av_channel_layout_channel_from_index(const AVChannelLayout *channel_layout, unsigned int idx);
723
724/**
725 * Get the index of a given channel in a channel layout. In case multiple
726 * channels are found, only the first match will be returned.
727 *
728 * @param channel_layout input channel layout
729 * @param channel the channel whose index to obtain
730 * @return index of channel in channel_layout on success or a negative number if
731 * channel is not present in channel_layout.
732 */
733int av_channel_layout_index_from_channel(const AVChannelLayout *channel_layout,
734 enum AVChannel channel);
735
736/**
737 * Get the index in a channel layout of a channel described by the given string.
738 * In case multiple channels are found, only the first match will be returned.
739 *
740 * This function accepts channel names in the same format as
741 * @ref av_channel_from_string().
742 *
743 * @param channel_layout input channel layout
744 * @param name string describing the channel whose index to obtain
745 * @return a channel index described by the given string, or a negative AVERROR
746 * value.
747 */
748int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout,
749 const char *name);
750
751/**
752 * Get a channel described by the given string.
753 *
754 * This function accepts channel names in the same format as
755 * @ref av_channel_from_string().
756 *
757 * @param channel_layout input channel layout
758 * @param name string describing the channel to obtain
759 * @return a channel described by the given string in channel_layout on success
760 * or AV_CHAN_NONE on failure (if the string is not valid or the channel
761 * order is unspecified)
762 */
763enum AVChannel
764av_channel_layout_channel_from_string(const AVChannelLayout *channel_layout,
765 const char *name);
766
767/**
768 * Find out what channels from a given set are present in a channel layout,
769 * without regard for their positions.
770 *
771 * @param channel_layout input channel layout
772 * @param mask a combination of AV_CH_* representing a set of channels
773 * @return a bitfield representing all the channels from mask that are present
774 * in channel_layout
775 */
776uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout,
777 uint64_t mask);
778
779/**
780 * Check whether a channel layout is valid, i.e. can possibly describe audio
781 * data.
782 *
783 * @param channel_layout input channel layout
784 * @return 1 if channel_layout is valid, 0 otherwise.
785 */
786int av_channel_layout_check(const AVChannelLayout *channel_layout);
787
788/**
789 * Check whether two channel layouts are semantically the same, i.e. the same
790 * channels are present on the same positions in both.
791 *
792 * If one of the channel layouts is AV_CHANNEL_ORDER_UNSPEC, while the other is
793 * not, they are considered to be unequal. If both are AV_CHANNEL_ORDER_UNSPEC,
794 * they are considered equal iff the channel counts are the same in both.
795 *
796 * @param chl input channel layout
797 * @param chl1 input channel layout
798 * @return 0 if chl and chl1 are equal, 1 if they are not equal. A negative
799 * AVERROR code if one or both are invalid.
800 */
801int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1);
802
803/**
804 * @}
805 */
806
807#endif /* AVUTIL_CHANNEL_LAYOUT_H */
808

source code of include/x86_64-linux-gnu/libavutil/channel_layout.h