#ifndef foochannelmaphfoo #define foochannelmaphfoo /*** This file is part of PulseAudio. Copyright 2005-2006 Lennart Poettering Copyright 2006 Pierre Ossman for Cendio AB PulseAudio 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. PulseAudio 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 General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with PulseAudio; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. ***/ #include #include #include #include /** \page channelmap Channel Maps * * \section overv_sec Overview * * Channel maps provide a way to associate channels in a stream with a * specific speaker position. This relieves applications of having to * make sure their channel order is identical to the final output. * * \section init_sec Initialisation * * A channel map consists of an array of \ref pa_channel_position values, * one for each channel. This array is stored together with a channel count * in a pa_channel_map structure. * * Before filling the structure, the application must initialise it using * pa_channel_map_init(). There are also a number of convenience functions * for standard channel mappings: * * \li pa_channel_map_init_mono() - Create a channel map with only mono audio. * \li pa_channel_map_init_stereo() - Create a standard stereo mapping. * \li pa_channel_map_init_auto() - Create a standard channel map for a specific number of channels * \li pa_channel_map_init_extend() - Similar to * pa_channel_map_init_auto() but synthesize a channel map if no * predefined one is known for the specified number of channels. * * \section conv_sec Convenience Functions * * The library contains a number of convenience functions for dealing with * channel maps: * * \li pa_channel_map_valid() - Tests if a channel map is valid. * \li pa_channel_map_equal() - Tests if two channel maps are identical. * \li pa_channel_map_snprint() - Creates a textual description of a channel * map. */ /** \file * Constants and routines for channel mapping handling */ PA_C_DECL_BEGIN /** A list of channel labels */ typedef enum pa_channel_position { PA_CHANNEL_POSITION_INVALID = -1, PA_CHANNEL_POSITION_MONO = 0, PA_CHANNEL_POSITION_LEFT, PA_CHANNEL_POSITION_RIGHT, PA_CHANNEL_POSITION_CENTER, PA_CHANNEL_POSITION_FRONT_LEFT = PA_CHANNEL_POSITION_LEFT, PA_CHANNEL_POSITION_FRONT_RIGHT = PA_CHANNEL_POSITION_RIGHT, PA_CHANNEL_POSITION_FRONT_CENTER = PA_CHANNEL_POSITION_CENTER, PA_CHANNEL_POSITION_REAR_CENTER, PA_CHANNEL_POSITION_REAR_LEFT, PA_CHANNEL_POSITION_REAR_RIGHT, PA_CHANNEL_POSITION_LFE, PA_CHANNEL_POSITION_SUBWOOFER = PA_CHANNEL_POSITION_LFE, PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER, PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER, PA_CHANNEL_POSITION_SIDE_LEFT, PA_CHANNEL_POSITION_SIDE_RIGHT, PA_CHANNEL_POSITION_AUX0, PA_CHANNEL_POSITION_AUX1, PA_CHANNEL_POSITION_AUX2, PA_CHANNEL_POSITION_AUX3, PA_CHANNEL_POSITION_AUX4, PA_CHANNEL_POSITION_AUX5, PA_CHANNEL_POSITION_AUX6, PA_CHANNEL_POSITION_AUX7, PA_CHANNEL_POSITION_AUX8, PA_CHANNEL_POSITION_AUX9, PA_CHANNEL_POSITION_AUX10, PA_CHANNEL_POSITION_AUX11, PA_CHANNEL_POSITION_AUX12, PA_CHANNEL_POSITION_AUX13, PA_CHANNEL_POSITION_AUX14, PA_CHANNEL_POSITION_AUX15, PA_CHANNEL_POSITION_AUX16, PA_CHANNEL_POSITION_AUX17, PA_CHANNEL_POSITION_AUX18, PA_CHANNEL_POSITION_AUX19, PA_CHANNEL_POSITION_AUX20, PA_CHANNEL_POSITION_AUX21, PA_CHANNEL_POSITION_AUX22, PA_CHANNEL_POSITION_AUX23, PA_CHANNEL_POSITION_AUX24, PA_CHANNEL_POSITION_AUX25, PA_CHANNEL_POSITION_AUX26, PA_CHANNEL_POSITION_AUX27, PA_CHANNEL_POSITION_AUX28, PA_CHANNEL_POSITION_AUX29, PA_CHANNEL_POSITION_AUX30, PA_CHANNEL_POSITION_AUX31, PA_CHANNEL_POSITION_TOP_CENTER, PA_CHANNEL_POSITION_TOP_FRONT_LEFT, PA_CHANNEL_POSITION_TOP_FRONT_RIGHT, PA_CHANNEL_POSITION_TOP_FRONT_CENTER, PA_CHANNEL_POSITION_TOP_REAR_LEFT, PA_CHANNEL_POSITION_TOP_REAR_RIGHT, PA_CHANNEL_POSITION_TOP_REAR_CENTER, PA_CHANNEL_POSITION_MAX } pa_channel_position_t; /** \cond fulldocs */ #define PA_CHANNEL_POSITION_INVALID PA_CHANNEL_POSITION_INVALID #define PA_CHANNEL_POSITION_MONO PA_CHANNEL_POSITION_MONO #define PA_CHANNEL_POSITION_LEFT PA_CHANNEL_POSITION_LEFT #define PA_CHANNEL_POSITION_RIGHT PA_CHANNEL_POSITION_RIGHT #define PA_CHANNEL_POSITION_CENTER PA_CHANNEL_POSITION_CENTER #define PA_CHANNEL_POSITION_FRONT_LEFT PA_CHANNEL_POSITION_FRONT_LEFT #define PA_CHANNEL_POSITION_FRONT_RIGHT PA_CHANNEL_POSITION_FRONT_RIGHT #define PA_CHANNEL_POSITION_FRONT_CENTER PA_CHANNEL_POSITION_FRONT_CENTER #define PA_CHANNEL_POSITION_REAR_CENTER PA_CHANNEL_POSITION_REAR_CENTER #define PA_CHANNEL_POSITION_REAR_LEFT PA_CHANNEL_POSITION_REAR_LEFT #define PA_CHANNEL_POSITION_REAR_RIGHT PA_CHANNEL_POSITION_REAR_RIGHT #define PA_CHANNEL_POSITION_LFE PA_CHANNEL_POSITION_LFE #define PA_CHANNEL_POSITION_SUBWOOFER PA_CHANNEL_POSITION_SUBWOOFER #define PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER #define PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER #define PA_CHANNEL_POSITION_SIDE_LEFT PA_CHANNEL_POSITION_SIDE_LEFT #define PA_CHANNEL_POSITION_SIDE_RIGHT PA_CHANNEL_POSITION_SIDE_RIGHT #define PA_CHANNEL_POSITION_AUX0 PA_CHANNEL_POSITION_AUX0 #define PA_CHANNEL_POSITION_AUX1 PA_CHANNEL_POSITION_AUX1 #define PA_CHANNEL_POSITION_AUX2 PA_CHANNEL_POSITION_AUX2 #define PA_CHANNEL_POSITION_AUX3 PA_CHANNEL_POSITION_AUX3 #define PA_CHANNEL_POSITION_AUX4 PA_CHANNEL_POSITION_AUX4 #define PA_CHANNEL_POSITION_AUX5 PA_CHANNEL_POSITION_AUX5 #define PA_CHANNEL_POSITION_AUX6 PA_CHANNEL_POSITION_AUX6 #define PA_CHANNEL_POSITION_AUX7 PA_CHANNEL_POSITION_AUX7 #define PA_CHANNEL_POSITION_AUX8 PA_CHANNEL_POSITION_AUX8 #define PA_CHANNEL_POSITION_AUX9 PA_CHANNEL_POSITION_AUX9 #define PA_CHANNEL_POSITION_AUX10 PA_CHANNEL_POSITION_AUX10 #define PA_CHANNEL_POSITION_AUX11 PA_CHANNEL_POSITION_AUX11 #define PA_CHANNEL_POSITION_AUX12 PA_CHANNEL_POSITION_AUX12 #define PA_CHANNEL_POSITION_AUX13 PA_CHANNEL_POSITION_AUX13 #define PA_CHANNEL_POSITION_AUX14 PA_CHANNEL_POSITION_AUX14 #define PA_CHANNEL_POSITION_AUX15 PA_CHANNEL_POSITION_AUX15 #define PA_CHANNEL_POSITION_AUX16 PA_CHANNEL_POSITION_AUX16 #define PA_CHANNEL_POSITION_AUX17 PA_CHANNEL_POSITION_AUX17 #define PA_CHANNEL_POSITION_AUX18 PA_CHANNEL_POSITION_AUX18 #define PA_CHANNEL_POSITION_AUX19 PA_CHANNEL_POSITION_AUX19 #define PA_CHANNEL_POSITION_AUX20 PA_CHANNEL_POSITION_AUX20 #define PA_CHANNEL_POSITION_AUX21 PA_CHANNEL_POSITION_AUX21 #define PA_CHANNEL_POSITION_AUX22 PA_CHANNEL_POSITION_AUX22 #define PA_CHANNEL_POSITION_AUX23 PA_CHANNEL_POSITION_AUX23 #define PA_CHANNEL_POSITION_AUX24 PA_CHANNEL_POSITION_AUX24 #define PA_CHANNEL_POSITION_AUX25 PA_CHANNEL_POSITION_AUX25 #define PA_CHANNEL_POSITION_AUX26 PA_CHANNEL_POSITION_AUX26 #define PA_CHANNEL_POSITION_AUX27 PA_CHANNEL_POSITION_AUX27 #define PA_CHANNEL_POSITION_AUX28 PA_CHANNEL_POSITION_AUX28 #define PA_CHANNEL_POSITION_AUX29 PA_CHANNEL_POSITION_AUX29 #define PA_CHANNEL_POSITION_AUX30 PA_CHANNEL_POSITION_AUX30 #define PA_CHANNEL_POSITION_AUX31 PA_CHANNEL_POSITION_AUX31 #define PA_CHANNEL_POSITION_TOP_CENTER PA_CHANNEL_POSITION_TOP_CENTER #define PA_CHANNEL_POSITION_TOP_FRONT_LEFT PA_CHANNEL_POSITION_TOP_FRONT_LEFT #define PA_CHANNEL_POSITION_TOP_FRONT_RIGHT PA_CHANNEL_POSITION_TOP_FRONT_RIGHT #define PA_CHANNEL_POSITION_TOP_FRONT_CENTER PA_CHANNEL_POSITION_TOP_FRONT_CENTER #define PA_CHANNEL_POSITION_TOP_REAR_LEFT PA_CHANNEL_POSITION_TOP_REAR_LEFT #define PA_CHANNEL_POSITION_TOP_REAR_RIGHT PA_CHANNEL_POSITION_TOP_REAR_RIGHT #define PA_CHANNEL_POSITION_TOP_REAR_CENTER PA_CHANNEL_POSITION_TOP_REAR_CENTER #define PA_CHANNEL_POSITION_MAX PA_CHANNEL_POSITION_MAX /** \endcond */ /** A list of channel mapping definitions for pa_channel_map_init_auto() */ typedef enum pa_channel_map_def { PA_CHANNEL_MAP_AIFF, /**< The mapping from RFC3551, which is based on AIFF-C */ PA_CHANNEL_MAP_ALSA, /**< The default mapping used by ALSA */ PA_CHANNEL_MAP_AUX, /**< Only aux channels */ PA_CHANNEL_MAP_WAVEEX, /**< Microsoft's WAVEFORMATEXTENSIBLE mapping */ PA_CHANNEL_MAP_OSS, /**< The default channel mapping used by OSS as defined in the OSS 4.0 API specs */ /**< Upper limit of valid channel mapping definitions */ PA_CHANNEL_MAP_DEF_MAX, PA_CHANNEL_MAP_DEFAULT = PA_CHANNEL_MAP_AIFF /**< The default channel map */ } pa_channel_map_def_t; /** \cond fulldocs */ #define PA_CHANNEL_MAP_AIFF PA_CHANNEL_MAP_AIFF #define PA_CHANNEL_MAP_ALSA PA_CHANNEL_MAP_ALSA #define PA_CHANNEL_MAP_AUX PA_CHANNEL_MAP_AUX #define PA_CHANNEL_MAP_WAVEEX PA_CHANNEL_MAP_WAVEEX #define PA_CHANNEL_MAP_OSS PA_CHANNEL_MAP_OSS #define PA_CHANNEL_MAP_DEF_MAX PA_CHANNEL_MAP_DEF_MAX #define PA_CHANNEL_MAP_DEFAULT PA_CHANNEL_MAP_DEFAULT /** \endcond */ /** A channel map which can be used to attach labels to specific * channels of a stream. These values are relevant for conversion and * mixing of streams */ typedef struct pa_channel_map { uint8_t channels; /**< Number of channels */ pa_channel_position_t map[PA_CHANNELS_MAX]; /**< Channel labels */ } pa_channel_map; /** Initialize the specified channel map and return a pointer to * it. The channel map will have a defined state but * pa_channel_map_valid() will fail for it. */ pa_channel_map* pa_channel_map_init(pa_channel_map *m); /** Initialize the specified channel map for monaural audio and return a pointer to it */ pa_channel_map* pa_channel_map_init_mono(pa_channel_map *m); /** Initialize the specified channel map for stereophonic audio and return a pointer to it */ pa_channel_map* pa_channel_map_init_stereo(pa_channel_map *m); /** Initialize the specified channel map for the specified number of * channels using default labels and return a pointer to it. This call * will fail (return NULL) if there is no default channel map known for this * specific number of channels and mapping. */ pa_channel_map* pa_channel_map_init_auto(pa_channel_map *m, unsigned channels, pa_channel_map_def_t def); /** Similar to pa_channel_map_init_auto() but instead of failing if no * default mapping is known with the specified parameters it will * synthesize a mapping based on a known mapping with fewer channels * and fill up the rest with AUX0...AUX31 channels \since 0.9.11 */ pa_channel_map* pa_channel_map_init_extend(pa_channel_map *m, unsigned channels, pa_channel_map_def_t def); /** Return a text label for the specified channel position */ const char* pa_channel_position_to_string(pa_channel_position_t pos) PA_GCC_PURE; /** Return a human readable text label for the specified channel position. \since 0.9.7 */ const char* pa_channel_position_to_pretty_string(pa_channel_position_t pos); /** The maximum length of strings returned by * pa_channel_map_snprint(). Please note that this value can change * with any release without warning and without being considered API * or ABI breakage. You should not use this definition anywhere where * it might become part of an ABI. */ #define PA_CHANNEL_MAP_SNPRINT_MAX 336 /** Make a human readable string from the specified channel map */ char* pa_channel_map_snprint(char *s, size_t l, const pa_channel_map *map); /** Parse a channel position list or well-known mapping name into a * channel map structure. This turns the output of * pa_channel_map_snprint() and pa_channel_map_to_name() back into a * pa_channel_map */ pa_channel_map *pa_channel_map_parse(pa_channel_map *map, const char *s); /** Compare two channel maps. Return 1 if both match. */ int pa_channel_map_equal(const pa_channel_map *a, const pa_channel_map *b) PA_GCC_PURE; /** Return non-zero if the specified channel map is considered valid */ int pa_channel_map_valid(const pa_channel_map *map) PA_GCC_PURE; /** Return non-zero if the specified channel map is compatible with * the specified sample spec. \since 0.9.12 */ int pa_channel_map_compatible(const pa_channel_map *map, const pa_sample_spec *ss) PA_GCC_PURE; /** Returns non-zero if every channel defined in b is also defined in a. \since 0.9.15 */ int pa_channel_map_superset(const pa_channel_map *a, const pa_channel_map *b) PA_GCC_PURE; /** Returns non-zero if it makes sense to apply a volume 'balance' * with this mapping, i.e. if there are left/right channels * available. \since 0.9.15 */ int pa_channel_map_can_balance(const pa_channel_map *map) PA_GCC_PURE; /** Returns non-zero if it makes sense to apply a volume 'fade' * (i.e. 'balance' between front and rear) with this mapping, i.e. if * there are front/rear channels available. \since 0.9.15 */ int pa_channel_map_can_fade(const pa_channel_map *map) PA_GCC_PURE; /** Tries to find a well-known channel mapping name for this channel * mapping. I.e. "stereo", "surround-71" and so on. If the channel * mapping is unknown NULL will be returned. This name can be parsed * with pa_channel_map_parse() \since 0.9.15 */ const char* pa_channel_map_to_name(const pa_channel_map *map) PA_GCC_PURE; /** Tries to find a human readable text label for this channel mapping. I.e. "Stereo", "Surround 7.1" and so on. If the channel mapping is unknown NULL will be returned. \since 0.9.15 */ const char* pa_channel_map_to_pretty_name(const pa_channel_map *map) PA_GCC_PURE; PA_C_DECL_END #endif