code.delx.au - pulseaudio/blob - src/pulse/channelmap.h

   1 #ifndef foochannelmaphfoo
   2 #define foochannelmaphfoo
   3
   4 /***
   5   This file is part of PulseAudio.
   6
   7   Copyright 2005-2006 Lennart Poettering
   8   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   9
  10   PulseAudio is free software; you can redistribute it and/or modify
  11   it under the terms of the GNU Lesser General Public License as published
  12   by the Free Software Foundation; either version 2.1 of the License,
  13   or (at your option) any later version.
  14
  15   PulseAudio is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with PulseAudio; if not, write to the Free Software
  22   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  23   USA.
  24 ***/
  25
  26 #include <pulse/sample.h>
  27 #include <pulse/cdecl.h>
  28 #include <pulse/gccmacro.h>
  29 #include <pulse/version.h>
  30
  31 /** \page channelmap Channel Maps
  32  *
  33  * \section overv_sec Overview
  34  *
  35  * Channel maps provide a way to associate channels in a stream with a
  36  * specific speaker position. This relieves applications of having to
  37  * make sure their channel order is identical to the final output.
  38  *
  39  * \section init_sec Initialisation
  40  *
  41  * A channel map consists of an array of \ref pa_channel_position values,
  42  * one for each channel. This array is stored together with a channel count
  43  * in a pa_channel_map structure.
  44  *
  45  * Before filling the structure, the application must initialise it using
  46  * pa_channel_map_init(). There are also a number of convenience functions
  47  * for standard channel mappings:
  48  *
  49  * \li pa_channel_map_init_mono() - Create a channel map with only mono audio.
  50  * \li pa_channel_map_init_stereo() - Create a standard stereo mapping.
  51  * \li pa_channel_map_init_auto() - Create a standard channel map for a specific number of channels
  52  * \li pa_channel_map_init_extend() - Similar to
  53  * pa_channel_map_init_auto() but synthesize a channel map if no
  54  * predefined one is known for the specified number of channels.
  55  *
  56  * \section conv_sec Convenience Functions
  57  *
  58  * The library contains a number of convenience functions for dealing with
  59  * channel maps:
  60  *
  61  * \li pa_channel_map_valid() - Tests if a channel map is valid.
  62  * \li pa_channel_map_equal() - Tests if two channel maps are identical.
  63  * \li pa_channel_map_snprint() - Creates a textual description of a channel
  64  *                                map.
  65  */
  66
  67 /** \file
  68  * Constants and routines for channel mapping handling */
  69
  70 PA_C_DECL_BEGIN
  71
  72 /** A list of channel labels */
  73 typedef enum pa_channel_position {
  74     PA_CHANNEL_POSITION_INVALID = -1,
  75     PA_CHANNEL_POSITION_MONO = 0,
  76
  77     PA_CHANNEL_POSITION_FRONT_LEFT,               /* Apple calls this 'Left' */
  78     PA_CHANNEL_POSITION_FRONT_RIGHT,              /* Apple calls this 'Right' */
  79     PA_CHANNEL_POSITION_FRONT_CENTER,             /* Apple calls this 'Center' */
  80
  81 /** \cond fulldocs */
  82     PA_CHANNEL_POSITION_LEFT = PA_CHANNEL_POSITION_FRONT_LEFT,
  83     PA_CHANNEL_POSITION_RIGHT = PA_CHANNEL_POSITION_FRONT_RIGHT,
  84     PA_CHANNEL_POSITION_CENTER = PA_CHANNEL_POSITION_FRONT_CENTER,
  85 /** \endcond */
  86
  87     PA_CHANNEL_POSITION_REAR_CENTER,              /* Microsoft calls this 'Back Center', Apple calls this 'Center Surround' */
  88     PA_CHANNEL_POSITION_REAR_LEFT,                /* Microsoft calls this 'Back Left', Apple calls this 'Left Surround' */
  89     PA_CHANNEL_POSITION_REAR_RIGHT,               /* Microsoft calls this 'Back Right', Apple calls this 'Right Surround' */
  90
  91     PA_CHANNEL_POSITION_LFE,                      /* Microsoft calls this 'Low Frequency', Apple calls this 'LFEScreen' */
  92 /** \cond fulldocs */
  93     PA_CHANNEL_POSITION_SUBWOOFER = PA_CHANNEL_POSITION_LFE,
  94 /** \endcond */
  95
  96     PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER,     /* Apple calls this 'Left Center' */
  97     PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER,    /* Apple calls this 'Right Center */
  98
  99     PA_CHANNEL_POSITION_SIDE_LEFT,                /* Apple calls this 'Left Surround Direct' */
 100     PA_CHANNEL_POSITION_SIDE_RIGHT,               /* Apple calls this 'Right Surround Direct' */
 101
 102     PA_CHANNEL_POSITION_AUX0,
 103     PA_CHANNEL_POSITION_AUX1,
 104     PA_CHANNEL_POSITION_AUX2,
 105     PA_CHANNEL_POSITION_AUX3,
 106     PA_CHANNEL_POSITION_AUX4,
 107     PA_CHANNEL_POSITION_AUX5,
 108     PA_CHANNEL_POSITION_AUX6,
 109     PA_CHANNEL_POSITION_AUX7,
 110     PA_CHANNEL_POSITION_AUX8,
 111     PA_CHANNEL_POSITION_AUX9,
 112     PA_CHANNEL_POSITION_AUX10,
 113     PA_CHANNEL_POSITION_AUX11,
 114     PA_CHANNEL_POSITION_AUX12,
 115     PA_CHANNEL_POSITION_AUX13,
 116     PA_CHANNEL_POSITION_AUX14,
 117     PA_CHANNEL_POSITION_AUX15,
 118     PA_CHANNEL_POSITION_AUX16,
 119     PA_CHANNEL_POSITION_AUX17,
 120     PA_CHANNEL_POSITION_AUX18,
 121     PA_CHANNEL_POSITION_AUX19,
 122     PA_CHANNEL_POSITION_AUX20,
 123     PA_CHANNEL_POSITION_AUX21,
 124     PA_CHANNEL_POSITION_AUX22,
 125     PA_CHANNEL_POSITION_AUX23,
 126     PA_CHANNEL_POSITION_AUX24,
 127     PA_CHANNEL_POSITION_AUX25,
 128     PA_CHANNEL_POSITION_AUX26,
 129     PA_CHANNEL_POSITION_AUX27,
 130     PA_CHANNEL_POSITION_AUX28,
 131     PA_CHANNEL_POSITION_AUX29,
 132     PA_CHANNEL_POSITION_AUX30,
 133     PA_CHANNEL_POSITION_AUX31,
 134
 135     PA_CHANNEL_POSITION_TOP_CENTER,               /* Apple calls this 'Top Center Surround' */
 136
 137     PA_CHANNEL_POSITION_TOP_FRONT_LEFT,           /* Apple calls this 'Vertical Height Left' */
 138     PA_CHANNEL_POSITION_TOP_FRONT_RIGHT,          /* Apple calls this 'Vertical Height Right' */
 139     PA_CHANNEL_POSITION_TOP_FRONT_CENTER,         /* Apple calls this 'Vertical Height Center' */
 140
 141     PA_CHANNEL_POSITION_TOP_REAR_LEFT,            /* Microsoft and Apple call this 'Top Back Left' */
 142     PA_CHANNEL_POSITION_TOP_REAR_RIGHT,           /* Microsoft and Apple call this 'Top Back Right' */
 143     PA_CHANNEL_POSITION_TOP_REAR_CENTER,          /* Microsoft and Apple call this 'Top Back Center' */
 144
 145     PA_CHANNEL_POSITION_MAX
 146 } pa_channel_position_t;
 147
 148 /** \cond fulldocs */
 149 #define PA_CHANNEL_POSITION_INVALID PA_CHANNEL_POSITION_INVALID
 150 #define PA_CHANNEL_POSITION_MONO PA_CHANNEL_POSITION_MONO
 151 #define PA_CHANNEL_POSITION_LEFT PA_CHANNEL_POSITION_LEFT
 152 #define PA_CHANNEL_POSITION_RIGHT PA_CHANNEL_POSITION_RIGHT
 153 #define PA_CHANNEL_POSITION_CENTER PA_CHANNEL_POSITION_CENTER
 154 #define PA_CHANNEL_POSITION_FRONT_LEFT PA_CHANNEL_POSITION_FRONT_LEFT
 155 #define PA_CHANNEL_POSITION_FRONT_RIGHT PA_CHANNEL_POSITION_FRONT_RIGHT
 156 #define PA_CHANNEL_POSITION_FRONT_CENTER PA_CHANNEL_POSITION_FRONT_CENTER
 157 #define PA_CHANNEL_POSITION_REAR_CENTER PA_CHANNEL_POSITION_REAR_CENTER
 158 #define PA_CHANNEL_POSITION_REAR_LEFT PA_CHANNEL_POSITION_REAR_LEFT
 159 #define PA_CHANNEL_POSITION_REAR_RIGHT PA_CHANNEL_POSITION_REAR_RIGHT
 160 #define PA_CHANNEL_POSITION_LFE PA_CHANNEL_POSITION_LFE
 161 #define PA_CHANNEL_POSITION_SUBWOOFER PA_CHANNEL_POSITION_SUBWOOFER
 162 #define PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER
 163 #define PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER
 164 #define PA_CHANNEL_POSITION_SIDE_LEFT PA_CHANNEL_POSITION_SIDE_LEFT
 165 #define PA_CHANNEL_POSITION_SIDE_RIGHT PA_CHANNEL_POSITION_SIDE_RIGHT
 166 #define PA_CHANNEL_POSITION_AUX0 PA_CHANNEL_POSITION_AUX0
 167 #define PA_CHANNEL_POSITION_AUX1 PA_CHANNEL_POSITION_AUX1
 168 #define PA_CHANNEL_POSITION_AUX2 PA_CHANNEL_POSITION_AUX2
 169 #define PA_CHANNEL_POSITION_AUX3 PA_CHANNEL_POSITION_AUX3
 170 #define PA_CHANNEL_POSITION_AUX4 PA_CHANNEL_POSITION_AUX4
 171 #define PA_CHANNEL_POSITION_AUX5 PA_CHANNEL_POSITION_AUX5
 172 #define PA_CHANNEL_POSITION_AUX6 PA_CHANNEL_POSITION_AUX6
 173 #define PA_CHANNEL_POSITION_AUX7 PA_CHANNEL_POSITION_AUX7
 174 #define PA_CHANNEL_POSITION_AUX8 PA_CHANNEL_POSITION_AUX8
 175 #define PA_CHANNEL_POSITION_AUX9 PA_CHANNEL_POSITION_AUX9
 176 #define PA_CHANNEL_POSITION_AUX10 PA_CHANNEL_POSITION_AUX10
 177 #define PA_CHANNEL_POSITION_AUX11 PA_CHANNEL_POSITION_AUX11
 178 #define PA_CHANNEL_POSITION_AUX12 PA_CHANNEL_POSITION_AUX12
 179 #define PA_CHANNEL_POSITION_AUX13 PA_CHANNEL_POSITION_AUX13
 180 #define PA_CHANNEL_POSITION_AUX14 PA_CHANNEL_POSITION_AUX14
 181 #define PA_CHANNEL_POSITION_AUX15 PA_CHANNEL_POSITION_AUX15
 182 #define PA_CHANNEL_POSITION_AUX16 PA_CHANNEL_POSITION_AUX16
 183 #define PA_CHANNEL_POSITION_AUX17 PA_CHANNEL_POSITION_AUX17
 184 #define PA_CHANNEL_POSITION_AUX18 PA_CHANNEL_POSITION_AUX18
 185 #define PA_CHANNEL_POSITION_AUX19 PA_CHANNEL_POSITION_AUX19
 186 #define PA_CHANNEL_POSITION_AUX20 PA_CHANNEL_POSITION_AUX20
 187 #define PA_CHANNEL_POSITION_AUX21 PA_CHANNEL_POSITION_AUX21
 188 #define PA_CHANNEL_POSITION_AUX22 PA_CHANNEL_POSITION_AUX22
 189 #define PA_CHANNEL_POSITION_AUX23 PA_CHANNEL_POSITION_AUX23
 190 #define PA_CHANNEL_POSITION_AUX24 PA_CHANNEL_POSITION_AUX24
 191 #define PA_CHANNEL_POSITION_AUX25 PA_CHANNEL_POSITION_AUX25
 192 #define PA_CHANNEL_POSITION_AUX26 PA_CHANNEL_POSITION_AUX26
 193 #define PA_CHANNEL_POSITION_AUX27 PA_CHANNEL_POSITION_AUX27
 194 #define PA_CHANNEL_POSITION_AUX28 PA_CHANNEL_POSITION_AUX28
 195 #define PA_CHANNEL_POSITION_AUX29 PA_CHANNEL_POSITION_AUX29
 196 #define PA_CHANNEL_POSITION_AUX30 PA_CHANNEL_POSITION_AUX30
 197 #define PA_CHANNEL_POSITION_AUX31 PA_CHANNEL_POSITION_AUX31
 198 #define PA_CHANNEL_POSITION_TOP_CENTER PA_CHANNEL_POSITION_TOP_CENTER
 199 #define PA_CHANNEL_POSITION_TOP_FRONT_LEFT PA_CHANNEL_POSITION_TOP_FRONT_LEFT
 200 #define PA_CHANNEL_POSITION_TOP_FRONT_RIGHT PA_CHANNEL_POSITION_TOP_FRONT_RIGHT
 201 #define PA_CHANNEL_POSITION_TOP_FRONT_CENTER PA_CHANNEL_POSITION_TOP_FRONT_CENTER
 202 #define PA_CHANNEL_POSITION_TOP_REAR_LEFT PA_CHANNEL_POSITION_TOP_REAR_LEFT
 203 #define PA_CHANNEL_POSITION_TOP_REAR_RIGHT PA_CHANNEL_POSITION_TOP_REAR_RIGHT
 204 #define PA_CHANNEL_POSITION_TOP_REAR_CENTER PA_CHANNEL_POSITION_TOP_REAR_CENTER
 205 #define PA_CHANNEL_POSITION_MAX PA_CHANNEL_POSITION_MAX
 206 /** \endcond */
 207
 208 /** A mask of channel positions. \since 0.9.16 */
 209 typedef uint64_t pa_channel_position_mask_t;
 210
 211 /** Makes a bit mask from a channel position. \since 0.9.16 */
 212 #define PA_CHANNEL_POSITION_MASK(f) ((pa_channel_position_mask_t) (1ULL << (f)))
 213
 214 /** A list of channel mapping definitions for pa_channel_map_init_auto() */
 215 typedef enum pa_channel_map_def {
 216     PA_CHANNEL_MAP_AIFF,
 217     /**< The mapping from RFC3551, which is based on AIFF-C */
 218
 219     PA_CHANNEL_MAP_ALSA,
 220     /**< The default mapping used by ALSA */
 221
 222     PA_CHANNEL_MAP_AUX,
 223     /**< Only aux channels */
 224
 225     PA_CHANNEL_MAP_WAVEEX,
 226     /**< Microsoft's WAVEFORMATEXTENSIBLE mapping */
 227
 228     PA_CHANNEL_MAP_OSS,
 229     /**< The default channel mapping used by OSS as defined in the OSS 4.0 API specs */
 230
 231     /**< Upper limit of valid channel mapping definitions */
 232     PA_CHANNEL_MAP_DEF_MAX,
 233
 234     PA_CHANNEL_MAP_DEFAULT = PA_CHANNEL_MAP_AIFF
 235     /**< The default channel map */
 236 } pa_channel_map_def_t;
 237
 238 /** \cond fulldocs */
 239 #define PA_CHANNEL_MAP_AIFF PA_CHANNEL_MAP_AIFF
 240 #define PA_CHANNEL_MAP_ALSA PA_CHANNEL_MAP_ALSA
 241 #define PA_CHANNEL_MAP_AUX PA_CHANNEL_MAP_AUX
 242 #define PA_CHANNEL_MAP_WAVEEX PA_CHANNEL_MAP_WAVEEX
 243 #define PA_CHANNEL_MAP_OSS PA_CHANNEL_MAP_OSS
 244 #define PA_CHANNEL_MAP_DEF_MAX PA_CHANNEL_MAP_DEF_MAX
 245 #define PA_CHANNEL_MAP_DEFAULT PA_CHANNEL_MAP_DEFAULT
 246 /** \endcond */
 247
 248 /** A channel map which can be used to attach labels to specific
 249  * channels of a stream. These values are relevant for conversion and
 250  * mixing of streams */
 251 typedef struct pa_channel_map {
 252     uint8_t channels;
 253     /**< Number of channels */
 254
 255     pa_channel_position_t map[PA_CHANNELS_MAX];
 256     /**< Channel labels */
 257 } pa_channel_map;
 258
 259 /** Initialize the specified channel map and return a pointer to
 260  * it. The channel map will have a defined state but
 261  * pa_channel_map_valid() will fail for it. */
 262 pa_channel_map* pa_channel_map_init(pa_channel_map *m);
 263
 264 /** Initialize the specified channel map for monaural audio and return a pointer to it */
 265 pa_channel_map* pa_channel_map_init_mono(pa_channel_map *m);
 266
 267 /** Initialize the specified channel map for stereophonic audio and return a pointer to it */
 268 pa_channel_map* pa_channel_map_init_stereo(pa_channel_map *m);
 269
 270 /** Initialize the specified channel map for the specified number of
 271  * channels using default labels and return a pointer to it. This call
 272  * will fail (return NULL) if there is no default channel map known for this
 273  * specific number of channels and mapping. */
 274 pa_channel_map* pa_channel_map_init_auto(pa_channel_map *m, unsigned channels, pa_channel_map_def_t def);
 275
 276 /** Similar to pa_channel_map_init_auto() but instead of failing if no
 277  * default mapping is known with the specified parameters it will
 278  * synthesize a mapping based on a known mapping with fewer channels
 279  * and fill up the rest with AUX0...AUX31 channels  \since 0.9.11 */
 280 pa_channel_map* pa_channel_map_init_extend(pa_channel_map *m, unsigned channels, pa_channel_map_def_t def);
 281
 282 /** Return a text label for the specified channel position */
 283 const char* pa_channel_position_to_string(pa_channel_position_t pos) PA_GCC_PURE;
 284
 285 /* The inverse of pa_channel_position_to_string(). \since 0.9.16 */
 286 pa_channel_position_t pa_channel_position_from_string(const char *s) PA_GCC_PURE;
 287
 288 /** Return a human readable text label for the specified channel position. \since 0.9.7 */
 289 const char* pa_channel_position_to_pretty_string(pa_channel_position_t pos);
 290
 291 /** The maximum length of strings returned by
 292  * pa_channel_map_snprint(). Please note that this value can change
 293  * with any release without warning and without being considered API
 294  * or ABI breakage. You should not use this definition anywhere where
 295  * it might become part of an ABI. */
 296 #define PA_CHANNEL_MAP_SNPRINT_MAX 336
 297
 298 /** Make a human readable string from the specified channel map */
 299 char* pa_channel_map_snprint(char *s, size_t l, const pa_channel_map *map);
 300
 301 /** Parse a channel position list or well-known mapping name into a
 302  * channel map structure. This turns the output of
 303  * pa_channel_map_snprint() and pa_channel_map_to_name() back into a
 304  * pa_channel_map */
 305 pa_channel_map *pa_channel_map_parse(pa_channel_map *map, const char *s);
 306
 307 /** Compare two channel maps. Return 1 if both match. */
 308 int pa_channel_map_equal(const pa_channel_map *a, const pa_channel_map *b) PA_GCC_PURE;
 309
 310 /** Return non-zero if the specified channel map is considered valid */
 311 int pa_channel_map_valid(const pa_channel_map *map) PA_GCC_PURE;
 312
 313 /** Return non-zero if the specified channel map is compatible with
 314  * the specified sample spec. \since 0.9.12 */
 315 int pa_channel_map_compatible(const pa_channel_map *map, const pa_sample_spec *ss) PA_GCC_PURE;
 316
 317 /** Returns non-zero if every channel defined in b is also defined in a. \since 0.9.15 */
 318 int pa_channel_map_superset(const pa_channel_map *a, const pa_channel_map *b) PA_GCC_PURE;
 319
 320 /** Returns non-zero if it makes sense to apply a volume 'balance'
 321  * with this mapping, i.e. if there are left/right channels
 322  * available. \since 0.9.15 */
 323 int pa_channel_map_can_balance(const pa_channel_map *map) PA_GCC_PURE;
 324
 325 /** Returns non-zero if it makes sense to apply a volume 'fade'
 326  * (i.e. 'balance' between front and rear) with this mapping, i.e. if
 327  * there are front/rear channels available. \since 0.9.15 */
 328 int pa_channel_map_can_fade(const pa_channel_map *map) PA_GCC_PURE;
 329
 330 /** Tries to find a well-known channel mapping name for this channel
 331  * mapping. I.e. "stereo", "surround-71" and so on. If the channel
 332  * mapping is unknown NULL will be returned. This name can be parsed
 333  * with pa_channel_map_parse() \since 0.9.15 */
 334 const char* pa_channel_map_to_name(const pa_channel_map *map) PA_GCC_PURE;
 335
 336 /** Tries to find a human readable text label for this channel
 337 mapping. I.e. "Stereo", "Surround 7.1" and so on. If the channel
 338 mapping is unknown NULL will be returned. \since 0.9.15 */
 339 const char* pa_channel_map_to_pretty_name(const pa_channel_map *map) PA_GCC_PURE;
 340
 341 /** Returns TRUE if the specified channel position is available at
 342  * least once in the channel map. \since 0.9.16 */
 343 int pa_channel_map_has_position(const pa_channel_map *map, pa_channel_position_t p) PA_GCC_PURE;
 344
 345 /** Generates a bit mask from a channel map. \since 0.9.16 */
 346 pa_channel_position_mask_t pa_channel_map_mask(const pa_channel_map *map) PA_GCC_PURE;
 347
 348 PA_C_DECL_END
 349
 350 #endif