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#ifndef foochannelmaphfoo
#define foochannelmaphfoo
/* $Id$ */
/***
This file is part of polypaudio.
polypaudio 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.
polypaudio 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 polypaudio; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.
***/
#include <polyp/sample.h>
#include <polyp/cdecl.h>
/** \page channelmap Channel maps
*
* \section overv_sec Overview
*
* Channel maps provide a way to associate channels in a stream with a
* speaker. 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 up to
* six 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_MAX
} pa_channel_position_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 */
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 */
pa_channel_map* pa_channel_map_init_auto(pa_channel_map *m, unsigned channels);
/** Return a text label for the specified channel position */
const char* pa_channel_position_to_string(pa_channel_position_t pos);
/** The maximum length of strings returned by pa_channel_map_snprint() */
#define PA_CHANNEL_MAP_SNPRINT_MAX 64
/** 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);
/** Compare two channel maps. Return 1 if both match. */
int pa_channel_map_equal(const pa_channel_map *a, const pa_channel_map *b);
/** Return non-zero of the specified channel map is considered valid */
int pa_channel_map_valid(const pa_channel_map *map);
PA_C_DECL_END
#endif
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