/* * Copyright (c) 2006 Michael Niedermayer <[email protected]> * 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 { … }; enum AVChannelOrder { … }; /** * @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 … #define AV_CH_FRONT_RIGHT … #define AV_CH_FRONT_CENTER … #define AV_CH_LOW_FREQUENCY … #define AV_CH_BACK_LEFT … #define AV_CH_BACK_RIGHT … #define AV_CH_FRONT_LEFT_OF_CENTER … #define AV_CH_FRONT_RIGHT_OF_CENTER … #define AV_CH_BACK_CENTER … #define AV_CH_SIDE_LEFT … #define AV_CH_SIDE_RIGHT … #define AV_CH_TOP_CENTER … #define AV_CH_TOP_FRONT_LEFT … #define AV_CH_TOP_FRONT_CENTER … #define AV_CH_TOP_FRONT_RIGHT … #define AV_CH_TOP_BACK_LEFT … #define AV_CH_TOP_BACK_CENTER … #define AV_CH_TOP_BACK_RIGHT … #define AV_CH_STEREO_LEFT … #define AV_CH_STEREO_RIGHT … #define AV_CH_WIDE_LEFT … #define AV_CH_WIDE_RIGHT … #define AV_CH_SURROUND_DIRECT_LEFT … #define AV_CH_SURROUND_DIRECT_RIGHT … #define AV_CH_LOW_FREQUENCY_2 … #define AV_CH_TOP_SIDE_LEFT … #define AV_CH_TOP_SIDE_RIGHT … #define AV_CH_BOTTOM_FRONT_CENTER … #define AV_CH_BOTTOM_FRONT_LEFT … #define AV_CH_BOTTOM_FRONT_RIGHT … /** * @} * @defgroup channel_mask_c Audio channel layouts * @{ * */ #define AV_CH_LAYOUT_MONO … #define AV_CH_LAYOUT_STEREO … #define AV_CH_LAYOUT_2POINT1 … #define AV_CH_LAYOUT_2_1 … #define AV_CH_LAYOUT_SURROUND … #define AV_CH_LAYOUT_3POINT1 … #define AV_CH_LAYOUT_4POINT0 … #define AV_CH_LAYOUT_4POINT1 … #define AV_CH_LAYOUT_2_2 … #define AV_CH_LAYOUT_QUAD … #define AV_CH_LAYOUT_5POINT0 … #define AV_CH_LAYOUT_5POINT1 … #define AV_CH_LAYOUT_5POINT0_BACK … #define AV_CH_LAYOUT_5POINT1_BACK … #define AV_CH_LAYOUT_6POINT0 … #define AV_CH_LAYOUT_6POINT0_FRONT … #define AV_CH_LAYOUT_HEXAGONAL … #define AV_CH_LAYOUT_3POINT1POINT2 … #define AV_CH_LAYOUT_6POINT1 … #define AV_CH_LAYOUT_6POINT1_BACK … #define AV_CH_LAYOUT_6POINT1_FRONT … #define AV_CH_LAYOUT_7POINT0 … #define AV_CH_LAYOUT_7POINT0_FRONT … #define AV_CH_LAYOUT_7POINT1 … #define AV_CH_LAYOUT_7POINT1_WIDE … #define AV_CH_LAYOUT_7POINT1_WIDE_BACK … #define AV_CH_LAYOUT_5POINT1POINT2_BACK … #define AV_CH_LAYOUT_OCTAGONAL … #define AV_CH_LAYOUT_CUBE … #define AV_CH_LAYOUT_5POINT1POINT4_BACK … #define AV_CH_LAYOUT_7POINT1POINT2 … #define AV_CH_LAYOUT_7POINT1POINT4_BACK … #define AV_CH_LAYOUT_7POINT2POINT3 … #define AV_CH_LAYOUT_9POINT1POINT4_BACK … #define AV_CH_LAYOUT_HEXADECAGONAL … #define AV_CH_LAYOUT_STEREO_DOWNMIX … #define AV_CH_LAYOUT_22POINT2 … #define AV_CH_LAYOUT_7POINT1_TOP_BACK … enum AVMatrixEncoding { … }; /** * @} */ /** * 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. */ 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 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). */ 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) … /** * @name Common pre-defined channel layouts * @{ */ #define AV_CHANNEL_LAYOUT_MONO … #define AV_CHANNEL_LAYOUT_STEREO … #define AV_CHANNEL_LAYOUT_2POINT1 … #define AV_CHANNEL_LAYOUT_2_1 … #define AV_CHANNEL_LAYOUT_SURROUND … #define AV_CHANNEL_LAYOUT_3POINT1 … #define AV_CHANNEL_LAYOUT_4POINT0 … #define AV_CHANNEL_LAYOUT_4POINT1 … #define AV_CHANNEL_LAYOUT_2_2 … #define AV_CHANNEL_LAYOUT_QUAD … #define AV_CHANNEL_LAYOUT_5POINT0 … #define AV_CHANNEL_LAYOUT_5POINT1 … #define AV_CHANNEL_LAYOUT_5POINT0_BACK … #define AV_CHANNEL_LAYOUT_5POINT1_BACK … #define AV_CHANNEL_LAYOUT_6POINT0 … #define AV_CHANNEL_LAYOUT_6POINT0_FRONT … #define AV_CHANNEL_LAYOUT_3POINT1POINT2 … #define AV_CHANNEL_LAYOUT_HEXAGONAL … #define AV_CHANNEL_LAYOUT_6POINT1 … #define AV_CHANNEL_LAYOUT_6POINT1_BACK … #define AV_CHANNEL_LAYOUT_6POINT1_FRONT … #define AV_CHANNEL_LAYOUT_7POINT0 … #define AV_CHANNEL_LAYOUT_7POINT0_FRONT … #define AV_CHANNEL_LAYOUT_7POINT1 … #define AV_CHANNEL_LAYOUT_7POINT1_WIDE … #define AV_CHANNEL_LAYOUT_7POINT1_WIDE_BACK … #define AV_CHANNEL_LAYOUT_5POINT1POINT2_BACK … #define AV_CHANNEL_LAYOUT_OCTAGONAL … #define AV_CHANNEL_LAYOUT_CUBE … #define AV_CHANNEL_LAYOUT_5POINT1POINT4_BACK … #define AV_CHANNEL_LAYOUT_7POINT1POINT2 … #define AV_CHANNEL_LAYOUT_7POINT1POINT4_BACK … #define AV_CHANNEL_LAYOUT_7POINT2POINT3 … #define AV_CHANNEL_LAYOUT_9POINT1POINT4_BACK … #define AV_CHANNEL_LAYOUT_HEXADECAGONAL … #define AV_CHANNEL_LAYOUT_STEREO_DOWNMIX … #define AV_CHANNEL_LAYOUT_22POINT2 … #define AV_CHANNEL_LAYOUT_7POINT1_TOP_BACK … #define AV_CHANNEL_LAYOUT_AMBISONIC_FIRST_ORDER … /** @} */ 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); /** * The conversion must be lossless. */ #define AV_CHANNEL_LAYOUT_RETYPE_FLAG_LOSSLESS … /** * 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 … /** * 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 */
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