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n8.2-dev
libavutil/channel_layout.h
762 строки
33 KB
Timo Rothenpieler
all: fix typos found by codespell
03 авг 2025, 14:48
03 авг 2025, 14:48
262d41c
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/* * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> * Copyright (c) 2008 Peter Ross * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVUTIL_CHANNEL_LAYOUT_H #define AVUTIL_CHANNEL_LAYOUT_H #include <stdint.h> #include <stdlib.h> #include "version.h" #include "attributes.h" /** * @file * @ingroup lavu_audio_channels * Public libavutil channel layout APIs header. */ /** * @defgroup lavu_audio_channels Audio channels * @ingroup lavu_audio * * Audio channel layout utility functions * * @{ */ enum AVChannel { /// Invalid channel index AV_CHAN_NONE = -1, AV_CHAN_FRONT_LEFT, AV_CHAN_FRONT_RIGHT, AV_CHAN_FRONT_CENTER, AV_CHAN_LOW_FREQUENCY, AV_CHAN_BACK_LEFT, AV_CHAN_BACK_RIGHT, AV_CHAN_FRONT_LEFT_OF_CENTER, AV_CHAN_FRONT_RIGHT_OF_CENTER, AV_CHAN_BACK_CENTER, AV_CHAN_SIDE_LEFT, AV_CHAN_SIDE_RIGHT, AV_CHAN_TOP_CENTER, AV_CHAN_TOP_FRONT_LEFT, AV_CHAN_TOP_FRONT_CENTER, AV_CHAN_TOP_FRONT_RIGHT, AV_CHAN_TOP_BACK_LEFT, AV_CHAN_TOP_BACK_CENTER, AV_CHAN_TOP_BACK_RIGHT, /** Stereo downmix. */ AV_CHAN_STEREO_LEFT = 29, /** See above. */ AV_CHAN_STEREO_RIGHT, AV_CHAN_WIDE_LEFT, AV_CHAN_WIDE_RIGHT, AV_CHAN_SURROUND_DIRECT_LEFT, AV_CHAN_SURROUND_DIRECT_RIGHT, AV_CHAN_LOW_FREQUENCY_2, AV_CHAN_TOP_SIDE_LEFT, AV_CHAN_TOP_SIDE_RIGHT, AV_CHAN_BOTTOM_FRONT_CENTER, AV_CHAN_BOTTOM_FRONT_LEFT, AV_CHAN_BOTTOM_FRONT_RIGHT, AV_CHAN_SIDE_SURROUND_LEFT, ///< +90 degrees, Lss, SiL AV_CHAN_SIDE_SURROUND_RIGHT, ///< -90 degrees, Rss, SiR AV_CHAN_TOP_SURROUND_LEFT, ///< +110 degrees, Lvs, TpLS AV_CHAN_TOP_SURROUND_RIGHT, ///< -110 degrees, Rvs, TpRS AV_CHAN_BINAURAL_LEFT = 61, AV_CHAN_BINAURAL_RIGHT, /** Channel is empty can be safely skipped. */ AV_CHAN_UNUSED = 0x200, /** Channel contains data, but its position is unknown. */ AV_CHAN_UNKNOWN = 0x300, /** * Range of channels between AV_CHAN_AMBISONIC_BASE and * AV_CHAN_AMBISONIC_END represent Ambisonic components using the ACN system. * * Given a channel id `<i>` between AV_CHAN_AMBISONIC_BASE and * AV_CHAN_AMBISONIC_END (inclusive), the ACN index of the channel `<n>` is * `<n> = <i> - AV_CHAN_AMBISONIC_BASE`. * * @note these values are only used for AV_CHANNEL_ORDER_CUSTOM channel * orderings, the AV_CHANNEL_ORDER_AMBISONIC ordering orders the channels * implicitly by their position in the stream. */ AV_CHAN_AMBISONIC_BASE = 0x400, // leave space for 1024 ids, which correspond to maximum order-32 harmonics, // which should be enough for the foreseeable use cases AV_CHAN_AMBISONIC_END = 0x7ff, }; enum AVChannelOrder { /** * Only the channel count is specified, without any further information * about the channel order. */ AV_CHANNEL_ORDER_UNSPEC, /** * The native channel order, i.e. the channels are in the same order in * which they are defined in the AVChannel enum. This supports up to 63 * different channels. */ AV_CHANNEL_ORDER_NATIVE, /** * The channel order does not correspond to any other predefined order and * is stored as an explicit map. For example, this could be used to support * layouts with 64 or more channels, or with empty/skipped (AV_CHAN_UNUSED) * channels at arbitrary positions. */ AV_CHANNEL_ORDER_CUSTOM, /** * The audio is represented as the decomposition of the sound field into * spherical harmonics. Each channel corresponds to a single expansion * component. Channels are ordered according to ACN (Ambisonic Channel * Number). * * The channel with the index n in the stream contains the spherical * harmonic of degree l and order m given by * @code{.unparsed} * l = floor(sqrt(n)), * m = n - l * (l + 1). * @endcode * * Conversely given a spherical harmonic of degree l and order m, the * corresponding channel index n is given by * @code{.unparsed} * n = l * (l + 1) + m. * @endcode * * Normalization is assumed to be SN3D (Schmidt Semi-Normalization) * as defined in AmbiX format $ 2.1. */ AV_CHANNEL_ORDER_AMBISONIC, /** * Number of channel orders, not part of ABI/API */ FF_CHANNEL_ORDER_NB }; /** * @defgroup channel_masks Audio channel masks * * A channel layout is a 64-bits integer with a bit set for every channel. * The number of bits set must be equal to the number of channels. * The value 0 means that the channel layout is not known. * @note this data structure is not powerful enough to handle channels * combinations that have the same channel multiple times, such as * dual-mono. * * @{ */ #define AV_CH_FRONT_LEFT (1ULL << AV_CHAN_FRONT_LEFT ) #define AV_CH_FRONT_RIGHT (1ULL << AV_CHAN_FRONT_RIGHT ) #define AV_CH_FRONT_CENTER (1ULL << AV_CHAN_FRONT_CENTER ) #define AV_CH_LOW_FREQUENCY (1ULL << AV_CHAN_LOW_FREQUENCY ) #define AV_CH_BACK_LEFT (1ULL << AV_CHAN_BACK_LEFT ) #define AV_CH_BACK_RIGHT (1ULL << AV_CHAN_BACK_RIGHT ) #define AV_CH_FRONT_LEFT_OF_CENTER (1ULL << AV_CHAN_FRONT_LEFT_OF_CENTER ) #define AV_CH_FRONT_RIGHT_OF_CENTER (1ULL << AV_CHAN_FRONT_RIGHT_OF_CENTER) #define AV_CH_BACK_CENTER (1ULL << AV_CHAN_BACK_CENTER ) #define AV_CH_SIDE_LEFT (1ULL << AV_CHAN_SIDE_LEFT ) #define AV_CH_SIDE_RIGHT (1ULL << AV_CHAN_SIDE_RIGHT ) #define AV_CH_TOP_CENTER (1ULL << AV_CHAN_TOP_CENTER ) #define AV_CH_TOP_FRONT_LEFT (1ULL << AV_CHAN_TOP_FRONT_LEFT ) #define AV_CH_TOP_FRONT_CENTER (1ULL << AV_CHAN_TOP_FRONT_CENTER ) #define AV_CH_TOP_FRONT_RIGHT (1ULL << AV_CHAN_TOP_FRONT_RIGHT ) #define AV_CH_TOP_BACK_LEFT (1ULL << AV_CHAN_TOP_BACK_LEFT ) #define AV_CH_TOP_BACK_CENTER (1ULL << AV_CHAN_TOP_BACK_CENTER ) #define AV_CH_TOP_BACK_RIGHT (1ULL << AV_CHAN_TOP_BACK_RIGHT ) #define AV_CH_STEREO_LEFT (1ULL << AV_CHAN_STEREO_LEFT ) #define AV_CH_STEREO_RIGHT (1ULL << AV_CHAN_STEREO_RIGHT ) #define AV_CH_WIDE_LEFT (1ULL << AV_CHAN_WIDE_LEFT ) #define AV_CH_WIDE_RIGHT (1ULL << AV_CHAN_WIDE_RIGHT ) #define AV_CH_SURROUND_DIRECT_LEFT (1ULL << AV_CHAN_SURROUND_DIRECT_LEFT ) #define AV_CH_SURROUND_DIRECT_RIGHT (1ULL << AV_CHAN_SURROUND_DIRECT_RIGHT) #define AV_CH_LOW_FREQUENCY_2 (1ULL << AV_CHAN_LOW_FREQUENCY_2 ) #define AV_CH_TOP_SIDE_LEFT (1ULL << AV_CHAN_TOP_SIDE_LEFT ) #define AV_CH_TOP_SIDE_RIGHT (1ULL << AV_CHAN_TOP_SIDE_RIGHT ) #define AV_CH_BOTTOM_FRONT_CENTER (1ULL << AV_CHAN_BOTTOM_FRONT_CENTER ) #define AV_CH_BOTTOM_FRONT_LEFT (1ULL << AV_CHAN_BOTTOM_FRONT_LEFT ) #define AV_CH_BOTTOM_FRONT_RIGHT (1ULL << AV_CHAN_BOTTOM_FRONT_RIGHT ) #define AV_CH_SIDE_SURROUND_LEFT (1ULL << AV_CHAN_SIDE_SURROUND_LEFT ) #define AV_CH_SIDE_SURROUND_RIGHT (1ULL << AV_CHAN_SIDE_SURROUND_RIGHT ) #define AV_CH_TOP_SURROUND_LEFT (1ULL << AV_CHAN_TOP_SURROUND_LEFT ) #define AV_CH_TOP_SURROUND_RIGHT (1ULL << AV_CHAN_TOP_SURROUND_RIGHT ) #define AV_CH_BINAURAL_LEFT (1ULL << AV_CHAN_BINAURAL_LEFT ) #define AV_CH_BINAURAL_RIGHT (1ULL << AV_CHAN_BINAURAL_RIGHT ) /** * @} * @defgroup channel_mask_c Audio channel layouts * @{ * */ #define AV_CH_LAYOUT_MONO (AV_CH_FRONT_CENTER) #define AV_CH_LAYOUT_STEREO (AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT) #define AV_CH_LAYOUT_2POINT1 (AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY) #define AV_CH_LAYOUT_2_1 (AV_CH_LAYOUT_STEREO|AV_CH_BACK_CENTER) #define AV_CH_LAYOUT_SURROUND (AV_CH_LAYOUT_STEREO|AV_CH_FRONT_CENTER) #define AV_CH_LAYOUT_3POINT1 (AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY) #define AV_CH_LAYOUT_4POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_CENTER) #define AV_CH_LAYOUT_4POINT1 (AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY) #define AV_CH_LAYOUT_2_2 (AV_CH_LAYOUT_STEREO|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT) #define AV_CH_LAYOUT_QUAD (AV_CH_LAYOUT_STEREO|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT) #define AV_CH_LAYOUT_5POINT0 (AV_CH_LAYOUT_SURROUND|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT) #define AV_CH_LAYOUT_5POINT1 (AV_CH_LAYOUT_5POINT0|AV_CH_LOW_FREQUENCY) #define AV_CH_LAYOUT_5POINT0_BACK (AV_CH_LAYOUT_SURROUND|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT) #define AV_CH_LAYOUT_5POINT1_BACK (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_LOW_FREQUENCY) #define AV_CH_LAYOUT_6POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_CENTER) #define AV_CH_LAYOUT_6POINT0_FRONT (AV_CH_LAYOUT_2_2|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER) #define AV_CH_LAYOUT_HEXAGONAL (AV_CH_LAYOUT_5POINT0_BACK|AV_CH_BACK_CENTER) #define AV_CH_LAYOUT_3POINT1POINT2 (AV_CH_LAYOUT_3POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT) #define AV_CH_LAYOUT_6POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_CENTER) #define AV_CH_LAYOUT_6POINT1_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER) #define AV_CH_LAYOUT_6POINT1_FRONT (AV_CH_LAYOUT_6POINT0_FRONT|AV_CH_LOW_FREQUENCY) #define AV_CH_LAYOUT_7POINT0 (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT) #define AV_CH_LAYOUT_7POINT0_FRONT (AV_CH_LAYOUT_5POINT0|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER) #define AV_CH_LAYOUT_7POINT1 (AV_CH_LAYOUT_5POINT1|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT) #define AV_CH_LAYOUT_7POINT1_WIDE (AV_CH_LAYOUT_5POINT1|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER) #define AV_CH_LAYOUT_7POINT1_WIDE_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER) #define AV_CH_LAYOUT_5POINT1POINT2 (AV_CH_LAYOUT_5POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT) #define AV_CH_LAYOUT_5POINT1POINT2_BACK (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT) #define AV_CH_LAYOUT_OCTAGONAL (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_CENTER|AV_CH_BACK_RIGHT) #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) #define AV_CH_LAYOUT_5POINT1POINT4_BACK (AV_CH_LAYOUT_5POINT1POINT2|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT) #define AV_CH_LAYOUT_7POINT1POINT2 (AV_CH_LAYOUT_7POINT1|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT) #define AV_CH_LAYOUT_7POINT1POINT4_BACK (AV_CH_LAYOUT_7POINT1POINT2|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT) #define AV_CH_LAYOUT_7POINT2POINT3 (AV_CH_LAYOUT_7POINT1POINT2|AV_CH_TOP_BACK_CENTER|AV_CH_LOW_FREQUENCY_2) #define AV_CH_LAYOUT_9POINT1POINT4_BACK (AV_CH_LAYOUT_7POINT1POINT4_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER) #define AV_CH_LAYOUT_9POINT1POINT6 (AV_CH_LAYOUT_9POINT1POINT4_BACK|AV_CH_TOP_SIDE_LEFT|AV_CH_TOP_SIDE_RIGHT) #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) #define AV_CH_LAYOUT_BINAURAL (AV_CH_BINAURAL_LEFT|AV_CH_BINAURAL_RIGHT) #define AV_CH_LAYOUT_STEREO_DOWNMIX (AV_CH_STEREO_LEFT|AV_CH_STEREO_RIGHT) #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) #define AV_CH_LAYOUT_7POINT1_TOP_BACK AV_CH_LAYOUT_5POINT1POINT2_BACK enum AVMatrixEncoding { AV_MATRIX_ENCODING_NONE, AV_MATRIX_ENCODING_DOLBY, AV_MATRIX_ENCODING_DPLII, AV_MATRIX_ENCODING_DPLIIX, AV_MATRIX_ENCODING_DPLIIZ, AV_MATRIX_ENCODING_DOLBYEX, AV_MATRIX_ENCODING_DOLBYHEADPHONE, AV_MATRIX_ENCODING_NB }; /** * @} */ /** * An AVChannelCustom defines a single channel within a custom order layout * * Unlike most structures in FFmpeg, sizeof(AVChannelCustom) is a part of the * public ABI. * * No new fields may be added to it without a major version bump. */ typedef struct AVChannelCustom { enum AVChannel id; char name[16]; void *opaque; } AVChannelCustom; /** * An AVChannelLayout holds information about the channel layout of audio data. * * A channel layout here is defined as a set of channels ordered in a specific * way (unless the channel order is AV_CHANNEL_ORDER_UNSPEC, in which case an * AVChannelLayout carries only the channel count). * All orders may be treated as if they were AV_CHANNEL_ORDER_UNSPEC by * ignoring everything but the channel count, as long as av_channel_layout_check() * considers they are valid. * * Unlike most structures in FFmpeg, sizeof(AVChannelLayout) is a part of the * public ABI and may be used by the caller. E.g. it may be allocated on stack * or embedded in caller-defined structs. * * AVChannelLayout can be initialized as follows: * - default initialization with {0}, followed by setting all used fields * correctly; * - by assigning one of the predefined AV_CHANNEL_LAYOUT_* initializers; * - with a constructor function, such as av_channel_layout_default(), * av_channel_layout_from_mask() or av_channel_layout_from_string(). * * The channel layout must be uninitialized with av_channel_layout_uninit() * * Copying an AVChannelLayout via assigning is forbidden, * av_channel_layout_copy() must be used instead (and its return value should * be checked) * * No new fields may be added to it without a major version bump, except for * new elements of the union fitting in sizeof(uint64_t). */ typedef struct AVChannelLayout { /** * Channel order used in this layout. * This is a mandatory field. */ enum AVChannelOrder order; /** * Number of channels in this layout. Mandatory field. */ int nb_channels; /** * Details about which channels are present in this layout. * For AV_CHANNEL_ORDER_UNSPEC, this field is undefined and must not be * used. */ union { /** * This member must be used for AV_CHANNEL_ORDER_NATIVE, and may be used * for AV_CHANNEL_ORDER_AMBISONIC to signal non-diegetic channels. * It is a bitmask, where the position of each set bit means that the * AVChannel with the corresponding value is present. * * I.e. when (mask & (1 << AV_CHAN_FOO)) is non-zero, then AV_CHAN_FOO * is present in the layout. Otherwise it is not present. * * @note when a channel layout using a bitmask is constructed or * modified manually (i.e. not using any of the av_channel_layout_* * functions), the code doing it must ensure that the number of set bits * is equal to nb_channels. */ uint64_t mask; /** * This member must be used when the channel order is * AV_CHANNEL_ORDER_CUSTOM. It is a nb_channels-sized array, with each * element signalling the presence of the AVChannel with the * corresponding value in map[i].id. * * I.e. when map[i].id is equal to AV_CHAN_FOO, then AV_CH_FOO is the * i-th channel in the audio data. * * When map[i].id is in the range between AV_CHAN_AMBISONIC_BASE and * AV_CHAN_AMBISONIC_END (inclusive), the channel contains an ambisonic * component with ACN index (as defined above) * n = map[i].id - AV_CHAN_AMBISONIC_BASE. * * map[i].name may be filled with a 0-terminated string, in which case * it will be used for the purpose of identifying the channel with the * convenience functions below. Otherwise it must be zeroed. */ AVChannelCustom *map; } u; /** * For some private data of the user. */ void *opaque; } AVChannelLayout; /** * Macro to define native channel layouts * * @note This doesn't use designated initializers for compatibility with C++ 17 and older. */ #define AV_CHANNEL_LAYOUT_MASK(nb, m) \ { /* .order */ AV_CHANNEL_ORDER_NATIVE, \ /* .nb_channels */ (nb), \ /* .u.mask */ { m }, \ /* .opaque */ NULL } /** * @name Common pre-defined channel layouts * @{ */ #define AV_CHANNEL_LAYOUT_MONO AV_CHANNEL_LAYOUT_MASK(1, AV_CH_LAYOUT_MONO) #define AV_CHANNEL_LAYOUT_STEREO AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO) #define AV_CHANNEL_LAYOUT_2POINT1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2POINT1) #define AV_CHANNEL_LAYOUT_2_1 AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_2_1) #define AV_CHANNEL_LAYOUT_SURROUND AV_CHANNEL_LAYOUT_MASK(3, AV_CH_LAYOUT_SURROUND) #define AV_CHANNEL_LAYOUT_3POINT1 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_3POINT1) #define AV_CHANNEL_LAYOUT_4POINT0 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_4POINT0) #define AV_CHANNEL_LAYOUT_4POINT1 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_4POINT1) #define AV_CHANNEL_LAYOUT_2_2 AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_2_2) #define AV_CHANNEL_LAYOUT_QUAD AV_CHANNEL_LAYOUT_MASK(4, AV_CH_LAYOUT_QUAD) #define AV_CHANNEL_LAYOUT_5POINT0 AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0) #define AV_CHANNEL_LAYOUT_5POINT1 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1) #define AV_CHANNEL_LAYOUT_5POINT0_BACK AV_CHANNEL_LAYOUT_MASK(5, AV_CH_LAYOUT_5POINT0_BACK) #define AV_CHANNEL_LAYOUT_5POINT1_BACK AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_5POINT1_BACK) #define AV_CHANNEL_LAYOUT_6POINT0 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0) #define AV_CHANNEL_LAYOUT_6POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_6POINT0_FRONT) #define AV_CHANNEL_LAYOUT_3POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_3POINT1POINT2) #define AV_CHANNEL_LAYOUT_HEXAGONAL AV_CHANNEL_LAYOUT_MASK(6, AV_CH_LAYOUT_HEXAGONAL) #define AV_CHANNEL_LAYOUT_6POINT1 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1) #define AV_CHANNEL_LAYOUT_6POINT1_BACK AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_BACK) #define AV_CHANNEL_LAYOUT_6POINT1_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_6POINT1_FRONT) #define AV_CHANNEL_LAYOUT_7POINT0 AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0) #define AV_CHANNEL_LAYOUT_7POINT0_FRONT AV_CHANNEL_LAYOUT_MASK(7, AV_CH_LAYOUT_7POINT0_FRONT) #define AV_CHANNEL_LAYOUT_7POINT1 AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1) #define AV_CHANNEL_LAYOUT_7POINT1_WIDE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE) #define AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_7POINT1_WIDE_BACK) #define AV_CHANNEL_LAYOUT_5POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_5POINT1POINT2) #define AV_CHANNEL_LAYOUT_5POINT1POINT2_BACK AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_5POINT1POINT2_BACK) #define AV_CHANNEL_LAYOUT_OCTAGONAL AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_OCTAGONAL) #define AV_CHANNEL_LAYOUT_CUBE AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_CUBE) #define AV_CHANNEL_LAYOUT_5POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(10, AV_CH_LAYOUT_5POINT1POINT4_BACK) #define AV_CHANNEL_LAYOUT_7POINT1POINT2 AV_CHANNEL_LAYOUT_MASK(10, AV_CH_LAYOUT_7POINT1POINT2) #define AV_CHANNEL_LAYOUT_7POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(12, AV_CH_LAYOUT_7POINT1POINT4_BACK) #define AV_CHANNEL_LAYOUT_7POINT2POINT3 AV_CHANNEL_LAYOUT_MASK(12, AV_CH_LAYOUT_7POINT2POINT3) #define AV_CHANNEL_LAYOUT_9POINT1POINT4_BACK AV_CHANNEL_LAYOUT_MASK(14, AV_CH_LAYOUT_9POINT1POINT4_BACK) #define AV_CHANNEL_LAYOUT_9POINT1POINT6 AV_CHANNEL_LAYOUT_MASK(16, AV_CH_LAYOUT_9POINT1POINT6) #define AV_CHANNEL_LAYOUT_HEXADECAGONAL AV_CHANNEL_LAYOUT_MASK(16, AV_CH_LAYOUT_HEXADECAGONAL) #define AV_CHANNEL_LAYOUT_BINAURAL AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_BINAURAL) #define AV_CHANNEL_LAYOUT_STEREO_DOWNMIX AV_CHANNEL_LAYOUT_MASK(2, AV_CH_LAYOUT_STEREO_DOWNMIX) #define AV_CHANNEL_LAYOUT_22POINT2 AV_CHANNEL_LAYOUT_MASK(24, AV_CH_LAYOUT_22POINT2) #define AV_CHANNEL_LAYOUT_7POINT1_TOP_BACK AV_CHANNEL_LAYOUT_5POINT1POINT2_BACK #define AV_CHANNEL_LAYOUT_AMBISONIC_FIRST_ORDER \ { /* .order */ AV_CHANNEL_ORDER_AMBISONIC, \ /* .nb_channels */ 4, \ /* .u.mask */ { 0 }, \ /* .opaque */ NULL } /** @} */ struct AVBPrint; /** * Get a human readable string in an abbreviated form describing a given channel. * This is the inverse function of @ref av_channel_from_string(). * * @param buf pre-allocated buffer where to put the generated string * @param buf_size size in bytes of the buffer. * @param channel the AVChannel whose name to get * @return amount of bytes needed to hold the output string, or a negative AVERROR * on failure. If the returned value is bigger than buf_size, then the * string was truncated. */ int av_channel_name(char *buf, size_t buf_size, enum AVChannel channel); /** * bprint variant of av_channel_name(). * * @note the string will be appended to the bprint buffer. */ void av_channel_name_bprint(struct AVBPrint *bp, enum AVChannel channel_id); /** * Get a human readable string describing a given channel. * * @param buf pre-allocated buffer where to put the generated string * @param buf_size size in bytes of the buffer. * @param channel the AVChannel whose description to get * @return amount of bytes needed to hold the output string, or a negative AVERROR * on failure. If the returned value is bigger than buf_size, then the * string was truncated. */ int av_channel_description(char *buf, size_t buf_size, enum AVChannel channel); /** * bprint variant of av_channel_description(). * * @note the string will be appended to the bprint buffer. */ void av_channel_description_bprint(struct AVBPrint *bp, enum AVChannel channel_id); /** * This is the inverse function of @ref av_channel_name(). * * @return the channel with the given name * AV_CHAN_NONE when name does not identify a known channel */ enum AVChannel av_channel_from_string(const char *name); /** * Initialize a custom channel layout with the specified number of channels. * The channel map will be allocated and the designation of all channels will * be set to AV_CHAN_UNKNOWN. * * This is only a convenience helper function, a custom channel layout can also * be constructed without using this. * * @param channel_layout the layout structure to be initialized * @param nb_channels the number of channels * * @return 0 on success * AVERROR(EINVAL) if the number of channels <= 0 * AVERROR(ENOMEM) if the channel map could not be allocated */ int av_channel_layout_custom_init(AVChannelLayout *channel_layout, int nb_channels); /** * Initialize a native channel layout from a bitmask indicating which channels * are present. * * @param channel_layout the layout structure to be initialized * @param mask bitmask describing the channel layout * * @return 0 on success * AVERROR(EINVAL) for invalid mask values */ int av_channel_layout_from_mask(AVChannelLayout *channel_layout, uint64_t mask); /** * Initialize a channel layout from a given string description. * The input string can be represented by: * - the formal channel layout name (returned by av_channel_layout_describe()) * - single or multiple channel names (returned by av_channel_name(), eg. "FL", * or concatenated with "+", each optionally containing a custom name after * a "@", eg. "FL@Left+FR@Right+LFE") * - a decimal or hexadecimal value of a native channel layout (eg. "4" or "0x4") * - the number of channels with default layout (eg. "4c") * - the number of unordered channels (eg. "4C" or "4 channels") * - the ambisonic order followed by optional non-diegetic channels (eg. * "ambisonic 2+stereo") * On error, the channel layout will remain uninitialized, but not necessarily * untouched. * * @param channel_layout uninitialized channel layout for the result * @param str string describing the channel layout * @return 0 on success parsing the channel layout * AVERROR(EINVAL) if an invalid channel layout string was provided * AVERROR(ENOMEM) if there was not enough memory */ int av_channel_layout_from_string(AVChannelLayout *channel_layout, const char *str); /** * Get the default channel layout for a given number of channels. * * @param ch_layout the layout structure to be initialized * @param nb_channels number of channels */ void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels); /** * Iterate over all standard channel layouts. * * @param opaque a pointer where libavutil will store the iteration state. Must * point to NULL to start the iteration. * * @return the standard channel layout or NULL when the iteration is * finished */ const AVChannelLayout *av_channel_layout_standard(void **opaque); /** * Free any allocated data in the channel layout and reset the channel * count to 0. * * @param channel_layout the layout structure to be uninitialized */ void av_channel_layout_uninit(AVChannelLayout *channel_layout); /** * Make a copy of a channel layout. This differs from just assigning src to dst * in that it allocates and copies the map for AV_CHANNEL_ORDER_CUSTOM. * * @note the destination channel_layout will be always uninitialized before copy. * * @param dst destination channel layout * @param src source channel layout * @return 0 on success, a negative AVERROR on error. */ int av_channel_layout_copy(AVChannelLayout *dst, const AVChannelLayout *src); /** * Get a human-readable string describing the channel layout properties. * The string will be in the same format that is accepted by * @ref av_channel_layout_from_string(), allowing to rebuild the same * channel layout, except for opaque pointers. * * @param channel_layout channel layout to be described * @param buf pre-allocated buffer where to put the generated string * @param buf_size size in bytes of the buffer. * @return amount of bytes needed to hold the output string, or a negative AVERROR * on failure. If the returned value is bigger than buf_size, then the * string was truncated. */ int av_channel_layout_describe(const AVChannelLayout *channel_layout, char *buf, size_t buf_size); /** * bprint variant of av_channel_layout_describe(). * * @note the string will be appended to the bprint buffer. * @return 0 on success, or a negative AVERROR value on failure. */ int av_channel_layout_describe_bprint(const AVChannelLayout *channel_layout, struct AVBPrint *bp); /** * Get the channel with the given index in a channel layout. * * @param channel_layout input channel layout * @param idx index of the channel * @return channel with the index idx in channel_layout on success or * AV_CHAN_NONE on failure (if idx is not valid or the channel order is * unspecified) */ enum AVChannel av_channel_layout_channel_from_index(const AVChannelLayout *channel_layout, unsigned int idx); /** * Get the index of a given channel in a channel layout. In case multiple * channels are found, only the first match will be returned. * * @param channel_layout input channel layout * @param channel the channel whose index to obtain * @return index of channel in channel_layout on success or a negative number if * channel is not present in channel_layout. */ int av_channel_layout_index_from_channel(const AVChannelLayout *channel_layout, enum AVChannel channel); /** * Get the index in a channel layout of a channel described by the given string. * In case multiple channels are found, only the first match will be returned. * * This function accepts channel names in the same format as * @ref av_channel_from_string(). * * @param channel_layout input channel layout * @param name string describing the channel whose index to obtain * @return a channel index described by the given string, or a negative AVERROR * value. */ int av_channel_layout_index_from_string(const AVChannelLayout *channel_layout, const char *name); /** * Get a channel described by the given string. * * This function accepts channel names in the same format as * @ref av_channel_from_string(). * * @param channel_layout input channel layout * @param name string describing the channel to obtain * @return a channel described by the given string in channel_layout on success * or AV_CHAN_NONE on failure (if the string is not valid or the channel * order is unspecified) */ enum AVChannel av_channel_layout_channel_from_string(const AVChannelLayout *channel_layout, const char *name); /** * Find out what channels from a given set are present in a channel layout, * without regard for their positions. * * @param channel_layout input channel layout * @param mask a combination of AV_CH_* representing a set of channels * @return a bitfield representing all the channels from mask that are present * in channel_layout */ uint64_t av_channel_layout_subset(const AVChannelLayout *channel_layout, uint64_t mask); /** * Check whether a channel layout is valid, i.e. can possibly describe audio * data. * * @param channel_layout input channel layout * @return 1 if channel_layout is valid, 0 otherwise. */ int av_channel_layout_check(const AVChannelLayout *channel_layout); /** * Check whether two channel layouts are semantically the same, i.e. the same * channels are present on the same positions in both. * * If one of the channel layouts is AV_CHANNEL_ORDER_UNSPEC, while the other is * not, they are considered to be unequal. If both are AV_CHANNEL_ORDER_UNSPEC, * they are considered equal iff the channel counts are the same in both. * * @param chl input channel layout * @param chl1 input channel layout * @return 0 if chl and chl1 are equal, 1 if they are not equal. A negative * AVERROR code if one or both are invalid. */ int av_channel_layout_compare(const AVChannelLayout *chl, const AVChannelLayout *chl1); /** * Return the order if the layout is n-th order standard-order ambisonic. * The presence of optional extra non-diegetic channels at the end is not taken * into account. * * @param channel_layout input channel layout * @return the order of the layout, a negative error code otherwise. */ int av_channel_layout_ambisonic_order(const AVChannelLayout *channel_layout); /** * The conversion must be lossless. */ #define AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS (1 << 0) /** * The specified retype target order is ignored and the simplest possible * (canonical) order is used for which the input layout can be losslessy * represented. */ #define AV_CHANNEL_LAYOUT_RETYPE_FLAG_CANONICAL (1 << 1) /** * Change the AVChannelOrder of a channel layout. * * Change of AVChannelOrder can be either lossless or lossy. In case of a * lossless conversion all the channel designations and the associated channel * names (if any) are kept. On a lossy conversion the channel names and channel * designations might be lost depending on the capabilities of the desired * AVChannelOrder. Note that some conversions are simply not possible in which * case this function returns AVERROR(ENOSYS). * * The following conversions are supported: * * Any -> Custom : Always possible, always lossless. * Any -> Unspecified: Always possible, lossless if channel designations * are all unknown and channel names are not used, lossy otherwise. * Custom -> Ambisonic : Possible if it contains ambisonic channels with * optional non-diegetic channels in the end. Lossy if the channels have * custom names, lossless otherwise. * Custom -> Native : Possible if it contains native channels in native * order. Lossy if the channels have custom names, lossless otherwise. * * On error this function keeps the original channel layout untouched. * * @param channel_layout channel layout which will be changed * @param order the desired channel layout order * @param flags a combination of AV_CHANNEL_LAYOUT_RETYPE_FLAG_* constants * @return 0 if the conversion was successful and lossless or if the channel * layout was already in the desired order * >0 if the conversion was successful but lossy * AVERROR(ENOSYS) if the conversion was not possible (or would be * lossy and AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS was specified) * AVERROR(EINVAL), AVERROR(ENOMEM) on error */ int av_channel_layout_retype(AVChannelLayout *channel_layout, enum AVChannelOrder order, int flags); /** * @} */ #endif /* AVUTIL_CHANNEL_LAYOUT_H */