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FFmpeg/libavutil/channel_layout.h
James Almer 05cff214b9 avutil/channel_layout: mention how the API user should treat channel orders it does not understand 
In case new orders are added in the future, existing library users can still
use the layout simply by ignoring everything but the channel count in it, so
make this explicit.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: James Almer <jamrial@gmail.com>
2022-09-22 10:22:19 -03:00

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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
* audio channel layout utility functions
*/
/**
* @addtogroup lavu_audio
* @{
*/
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,
/** 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_SILENCE)
* 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,
};
/**
* @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 )
#if FF_API_OLD_CHANNEL_LAYOUT
/** Channel mask value used for AVCodecContext.request_channel_layout
to indicate that the user requests the channel order of the decoder output
to be the native codec channel order.
@deprecated channel order is now indicated in a special field in
AVChannelLayout
*/
#define AV_CH_LAYOUT_NATIVE 0x8000000000000000ULL
#endif
/**
* @}
* @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_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_OCTAGONAL (AV_CH_LAYOUT_5POINT0|AV_CH_BACK_LEFT|AV_CH_BACK_CENTER|AV_CH_BACK_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_STEREO_DOWNMIX (AV_CH_STEREO_LEFT|AV_CH_STEREO_RIGHT)
#define AV_CH_LAYOUT_22POINT2 (AV_CH_LAYOUT_5POINT1_BACK|AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER|AV_CH_BACK_CENTER|AV_CH_LOW_FREQUENCY_2|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT|AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT|AV_CH_TOP_FRONT_CENTER|AV_CH_TOP_CENTER|AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_RIGHT|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)
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).
*
* Unlike most structures in Libav, 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 unitialized 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.
* Any value not defined in the AVChannelOrder enum in a layout that
* av_channel_layout_check() doesn't reject must be treated as if it was
* AV_CHANNEL_ORDER_UNSPEC.
* 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. Otherise it must be zeroed.
*/
AVChannelCustom *map;
} u;
/**
* For some private data of the user.
*/
void *opaque;
} AVChannelLayout;
#define AV_CHANNEL_LAYOUT_MASK(nb, m) \
{ .order = AV_CHANNEL_ORDER_NATIVE, .nb_channels = (nb), .u = { .mask = (m) }}
#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_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_OCTAGONAL AV_CHANNEL_LAYOUT_MASK(8, AV_CH_LAYOUT_OCTAGONAL)
#define AV_CHANNEL_LAYOUT_HEXADECAGONAL AV_CHANNEL_LAYOUT_MASK(16, AV_CH_LAYOUT_HEXADECAGONAL)
#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_AMBISONIC_FIRST_ORDER \
{ .order = AV_CHANNEL_ORDER_AMBISONIC, .nb_channels = 4, .u = { .mask = 0 }}
struct AVBPrint;
#if FF_API_OLD_CHANNEL_LAYOUT
/**
* Return a channel layout id that matches name, or 0 if no match is found.
*
* name can be one or several of the following notations,
* separated by '+' or '|':
* - the name of an usual channel layout (mono, stereo, 4.0, quad, 5.0,
* 5.0(side), 5.1, 5.1(side), 7.1, 7.1(wide), downmix);
* - the name of a single channel (FL, FR, FC, LFE, BL, BR, FLC, FRC, BC,
* SL, SR, TC, TFL, TFC, TFR, TBL, TBC, TBR, DL, DR);
* - a number of channels, in decimal, followed by 'c', yielding
* the default channel layout for that number of channels (@see
* av_get_default_channel_layout);
* - a channel layout mask, in hexadecimal starting with "0x" (see the
* AV_CH_* macros).
*
* Example: "stereo+FC" = "2c+FC" = "2c+1c" = "0x7"
*
* @deprecated use av_channel_layout_from_string()
*/
attribute_deprecated
uint64_t av_get_channel_layout(const char *name);
/**
* Return a channel layout and the number of channels based on the specified name.
*
* This function is similar to (@see av_get_channel_layout), but can also parse
* unknown channel layout specifications.
*
* @param[in] name channel layout specification string
* @param[out] channel_layout parsed channel layout (0 if unknown)
* @param[out] nb_channels number of channels
*
* @return 0 on success, AVERROR(EINVAL) if the parsing fails.
* @deprecated use av_channel_layout_from_string()
*/
attribute_deprecated
int av_get_extended_channel_layout(const char *name, uint64_t* channel_layout, int* nb_channels);
/**
* Return a description of a channel layout.
* If nb_channels is <= 0, it is guessed from the channel_layout.
*
* @param buf put here the string containing the channel layout
* @param buf_size size in bytes of the buffer
* @deprecated use av_channel_layout_describe()
*/
attribute_deprecated
void av_get_channel_layout_string(char *buf, int buf_size, int nb_channels, uint64_t channel_layout);
/**
* Append a description of a channel layout to a bprint buffer.
* @deprecated use av_channel_layout_describe()
*/
attribute_deprecated
void av_bprint_channel_layout(struct AVBPrint *bp, int nb_channels, uint64_t channel_layout);
/**
* Return the number of channels in the channel layout.
* @deprecated use AVChannelLayout.nb_channels
*/
attribute_deprecated
int av_get_channel_layout_nb_channels(uint64_t channel_layout);
/**
* Return default channel layout for a given number of channels.
*
* @deprecated use av_channel_layout_default()
*/
attribute_deprecated
int64_t av_get_default_channel_layout(int nb_channels);
/**
* Get the index of a channel in channel_layout.
*
* @param channel a channel layout describing exactly one channel which must be
* present in channel_layout.
*
* @return index of channel in channel_layout on success, a negative AVERROR
* on error.
*
* @deprecated use av_channel_layout_index_from_channel()
*/
attribute_deprecated
int av_get_channel_layout_channel_index(uint64_t channel_layout,
uint64_t channel);
/**
* Get the channel with the given index in channel_layout.
* @deprecated use av_channel_layout_channel_from_index()
*/
attribute_deprecated
uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index);
/**
* Get the name of a given channel.
*
* @return channel name on success, NULL on error.
*
* @deprecated use av_channel_name()
*/
attribute_deprecated
const char *av_get_channel_name(uint64_t channel);
/**
* Get the description of a given channel.
*
* @param channel a channel layout with a single channel
* @return channel description on success, NULL on error
* @deprecated use av_channel_description()
*/
attribute_deprecated
const char *av_get_channel_description(uint64_t channel);
/**
* Get the value and name of a standard channel layout.
*
* @param[in] index index in an internal list, starting at 0
* @param[out] layout channel layout mask
* @param[out] name name of the layout
* @return 0 if the layout exists,
* <0 if index is beyond the limits
* @deprecated use av_channel_layout_standard()
*/
attribute_deprecated
int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
const char **name);
#endif
/**
* 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.
* @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.
* @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 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")
*
* @param channel_layout input channel layout
* @param str string describing the channel layout
* @return 0 channel layout was detected, AVERROR_INVALIDATATA otherwise
*/
int av_channel_layout_from_string(AVChannelLayout *channel_layout,
const char *str);
/**
* Get the default channel layout for a given number of channels.
*
* @param channel_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
* @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
* @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
* @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
* @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);
/**
* @}
* @}
*/
#endif /* AVUTIL_CHANNEL_LAYOUT_H */
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