channel_layout.h (32445B)
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 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 }; 106 107 enum 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_UNUSED) 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 * Number of channel orders, not part of ABI/API 151 */ 152 FF_CHANNEL_ORDER_NB 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 243 244 enum AVMatrixEncoding { 245 AV_MATRIX_ENCODING_NONE, 246 AV_MATRIX_ENCODING_DOLBY, 247 AV_MATRIX_ENCODING_DPLII, 248 AV_MATRIX_ENCODING_DPLIIX, 249 AV_MATRIX_ENCODING_DPLIIZ, 250 AV_MATRIX_ENCODING_DOLBYEX, 251 AV_MATRIX_ENCODING_DOLBYHEADPHONE, 252 AV_MATRIX_ENCODING_NB 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; 271 } AVChannelCustom; 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 */ 308 enum AVChannelOrder order; 309 310 /** 311 * Number of channels in this layout. Mandatory field. 312 */ 313 int nb_channels; 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 */ 354 AVChannelCustom *map; 355 } u; 356 357 /** 358 * For some private data of the user. 359 */ 360 void *opaque; 361 } AVChannelLayout; 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 */ 524 int av_channel_layout_from_string(AVChannelLayout *channel_layout, 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 */ 564 int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src); 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 643 av_channel_layout_channel_from_string(const AVChannelLayout *channel_layout, 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 * The conversion must be lossless. 684 */ 685 #define AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS (1 << 0) 686 687 /** 688 * The specified retype target order is ignored and the simplest possible 689 * (canonical) order is used for which the input layout can be losslessy 690 * represented. 691 */ 692 #define AV_CHANNEL_LAYOUT_RETYPE_FLAG_CANONICAL (1 << 1) 693 694 /** 695 * Change the AVChannelOrder of a channel layout. 696 * 697 * Change of AVChannelOrder can be either lossless or lossy. In case of a 698 * lossless conversion all the channel designations and the associated channel 699 * names (if any) are kept. On a lossy conversion the channel names and channel 700 * designations might be lost depending on the capabilities of the desired 701 * AVChannelOrder. Note that some conversions are simply not possible in which 702 * case this function returns AVERROR(ENOSYS). 703 * 704 * The following conversions are supported: 705 * 706 * Any -> Custom : Always possible, always lossless. 707 * Any -> Unspecified: Always possible, lossless if channel designations 708 * are all unknown and channel names are not used, lossy otherwise. 709 * Custom -> Ambisonic : Possible if it contains ambisonic channels with 710 * optional non-diegetic channels in the end. Lossy if the channels have 711 * custom names, lossless otherwise. 712 * Custom -> Native : Possible if it contains native channels in native 713 * order. Lossy if the channels have custom names, lossless otherwise. 714 * 715 * On error this function keeps the original channel layout untouched. 716 * 717 * @param channel_layout channel layout which will be changed 718 * @param order the desired channel layout order 719 * @param flags a combination of AV_CHANNEL_LAYOUT_RETYPE_FLAG_* constants 720 * @return 0 if the conversion was successful and lossless or if the channel 721 * layout was already in the desired order 722 * >0 if the conversion was successful but lossy 723 * AVERROR(ENOSYS) if the conversion was not possible (or would be 724 * lossy and AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS was specified) 725 * AVERROR(EINVAL), AVERROR(ENOMEM) on error 726 */ 727 int av_channel_layout_retype(AVChannelLayout *channel_layout, enum AVChannelOrder order, int flags); 728 729 /** 730 * @} 731 */ 732 733 #endif /* AVUTIL_CHANNEL_LAYOUT_H */