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#ifndef foochannelmaphfoo
#define foochannelmaphfoo
/***
This file is part of PulseAudio.
Copyright 2005-2006 Lennart Poettering
Copyright 2006 Pierre Ossman <ossman@cendio.se> 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 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 <pulse/sample.h>
#include <pulse/cdecl.h>
#include <pulse/gccmacro.h>
/** \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 noone
* 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;
/** 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;
/** 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 monoaural 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 humand 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;
/** 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
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