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, see <http://www.gnu.org/licenses/>.
22***/
23
24#include <pulse/sample.h>
25#include <pulse/cdecl.h>
26#include <pulse/gccmacro.h>
27#include <pulse/version.h>
28
29/** \page channelmap Channel Maps
30 *
31 * \section overv_sec Overview
32 *
33 * Channel maps provide a way to associate channels in a stream with a
34 * specific speaker position. This relieves applications of having to
35 * make sure their channel order is identical to the final output.
36 *
37 * \section init_sec Initialisation
38 *
39 * A channel map consists of an array of \ref pa_channel_position values,
40 * one for each channel. This array is stored together with a channel count
41 * in a pa_channel_map structure.
42 *
43 * Before filling the structure, the application must initialise it using
44 * pa_channel_map_init(). There are also a number of convenience functions
45 * for standard channel mappings:
46 *
47 * \li pa_channel_map_init_mono() - Create a channel map with only mono audio.
48 * \li pa_channel_map_init_stereo() - Create a standard stereo mapping.
49 * \li pa_channel_map_init_auto() - Create a standard channel map for a specific
50 * number of channels.
51 * \li pa_channel_map_init_extend() - Similar to pa_channel_map_init_auto() but
52 * synthesize a channel map if no predefined
53 * one is known for the specified number of
54 * 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 * See also \subpage channelmap
71 */
72
73PA_C_DECL_BEGIN
74
75/** A list of channel labels */
76typedef enum pa_channel_position {
77 PA_CHANNEL_POSITION_INVALID = -1,
78 PA_CHANNEL_POSITION_MONO = 0,
79
80 PA_CHANNEL_POSITION_FRONT_LEFT, /**< Apple, Dolby call this 'Left' */
81 PA_CHANNEL_POSITION_FRONT_RIGHT, /**< Apple, Dolby call this 'Right' */
82 PA_CHANNEL_POSITION_FRONT_CENTER, /**< Apple, Dolby call this 'Center' */
83
84/** \cond fulldocs */
85 PA_CHANNEL_POSITION_LEFT = PA_CHANNEL_POSITION_FRONT_LEFT,
86 PA_CHANNEL_POSITION_RIGHT = PA_CHANNEL_POSITION_FRONT_RIGHT,
87 PA_CHANNEL_POSITION_CENTER = PA_CHANNEL_POSITION_FRONT_CENTER,
88/** \endcond */
89
90 PA_CHANNEL_POSITION_REAR_CENTER, /**< Microsoft calls this 'Back Center', Apple calls this 'Center Surround', Dolby calls this 'Surround Rear Center' */
91 PA_CHANNEL_POSITION_REAR_LEFT, /**< Microsoft calls this 'Back Left', Apple calls this 'Left Surround' (!), Dolby calls this 'Surround Rear Left' */
92 PA_CHANNEL_POSITION_REAR_RIGHT, /**< Microsoft calls this 'Back Right', Apple calls this 'Right Surround' (!), Dolby calls this 'Surround Rear Right' */
93
94 PA_CHANNEL_POSITION_LFE, /**< Microsoft calls this 'Low Frequency', Apple calls this 'LFEScreen' */
95/** \cond fulldocs */
96 PA_CHANNEL_POSITION_SUBWOOFER = PA_CHANNEL_POSITION_LFE,
97/** \endcond */
98
99 PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER, /**< Apple, Dolby call this 'Left Center' */
100 PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER, /**< Apple, Dolby call this 'Right Center */
101
102 PA_CHANNEL_POSITION_SIDE_LEFT, /**< Apple calls this 'Left Surround Direct', Dolby calls this 'Surround Left' (!) */
103 PA_CHANNEL_POSITION_SIDE_RIGHT, /**< Apple calls this 'Right Surround Direct', Dolby calls this 'Surround Right' (!) */
104
105 PA_CHANNEL_POSITION_AUX0,
106 PA_CHANNEL_POSITION_AUX1,
107 PA_CHANNEL_POSITION_AUX2,
108 PA_CHANNEL_POSITION_AUX3,
109 PA_CHANNEL_POSITION_AUX4,
110 PA_CHANNEL_POSITION_AUX5,
111 PA_CHANNEL_POSITION_AUX6,
112 PA_CHANNEL_POSITION_AUX7,
113 PA_CHANNEL_POSITION_AUX8,
114 PA_CHANNEL_POSITION_AUX9,
115 PA_CHANNEL_POSITION_AUX10,
116 PA_CHANNEL_POSITION_AUX11,
117 PA_CHANNEL_POSITION_AUX12,
118 PA_CHANNEL_POSITION_AUX13,
119 PA_CHANNEL_POSITION_AUX14,
120 PA_CHANNEL_POSITION_AUX15,
121 PA_CHANNEL_POSITION_AUX16,
122 PA_CHANNEL_POSITION_AUX17,
123 PA_CHANNEL_POSITION_AUX18,
124 PA_CHANNEL_POSITION_AUX19,
125 PA_CHANNEL_POSITION_AUX20,
126 PA_CHANNEL_POSITION_AUX21,
127 PA_CHANNEL_POSITION_AUX22,
128 PA_CHANNEL_POSITION_AUX23,
129 PA_CHANNEL_POSITION_AUX24,
130 PA_CHANNEL_POSITION_AUX25,
131 PA_CHANNEL_POSITION_AUX26,
132 PA_CHANNEL_POSITION_AUX27,
133 PA_CHANNEL_POSITION_AUX28,
134 PA_CHANNEL_POSITION_AUX29,
135 PA_CHANNEL_POSITION_AUX30,
136 PA_CHANNEL_POSITION_AUX31,
137
138 PA_CHANNEL_POSITION_TOP_CENTER, /**< Apple calls this 'Top Center Surround' */
139
140 PA_CHANNEL_POSITION_TOP_FRONT_LEFT, /**< Apple calls this 'Vertical Height Left' */
141 PA_CHANNEL_POSITION_TOP_FRONT_RIGHT, /**< Apple calls this 'Vertical Height Right' */
142 PA_CHANNEL_POSITION_TOP_FRONT_CENTER, /**< Apple calls this 'Vertical Height Center' */
143
144 PA_CHANNEL_POSITION_TOP_REAR_LEFT, /**< Microsoft and Apple call this 'Top Back Left' */
145 PA_CHANNEL_POSITION_TOP_REAR_RIGHT, /**< Microsoft and Apple call this 'Top Back Right' */
146 PA_CHANNEL_POSITION_TOP_REAR_CENTER, /**< Microsoft and Apple call this 'Top Back Center' */
147
148 PA_CHANNEL_POSITION_MAX
149} pa_channel_position_t;
150
151/** \cond fulldocs */
152#define PA_CHANNEL_POSITION_INVALID PA_CHANNEL_POSITION_INVALID
153#define PA_CHANNEL_POSITION_MONO PA_CHANNEL_POSITION_MONO
154#define PA_CHANNEL_POSITION_LEFT PA_CHANNEL_POSITION_LEFT
155#define PA_CHANNEL_POSITION_RIGHT PA_CHANNEL_POSITION_RIGHT
156#define PA_CHANNEL_POSITION_CENTER PA_CHANNEL_POSITION_CENTER
157#define PA_CHANNEL_POSITION_FRONT_LEFT PA_CHANNEL_POSITION_FRONT_LEFT
158#define PA_CHANNEL_POSITION_FRONT_RIGHT PA_CHANNEL_POSITION_FRONT_RIGHT
159#define PA_CHANNEL_POSITION_FRONT_CENTER PA_CHANNEL_POSITION_FRONT_CENTER
160#define PA_CHANNEL_POSITION_REAR_CENTER PA_CHANNEL_POSITION_REAR_CENTER
161#define PA_CHANNEL_POSITION_REAR_LEFT PA_CHANNEL_POSITION_REAR_LEFT
162#define PA_CHANNEL_POSITION_REAR_RIGHT PA_CHANNEL_POSITION_REAR_RIGHT
163#define PA_CHANNEL_POSITION_LFE PA_CHANNEL_POSITION_LFE
164#define PA_CHANNEL_POSITION_SUBWOOFER PA_CHANNEL_POSITION_SUBWOOFER
165#define PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER
166#define PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER
167#define PA_CHANNEL_POSITION_SIDE_LEFT PA_CHANNEL_POSITION_SIDE_LEFT
168#define PA_CHANNEL_POSITION_SIDE_RIGHT PA_CHANNEL_POSITION_SIDE_RIGHT
169#define PA_CHANNEL_POSITION_AUX0 PA_CHANNEL_POSITION_AUX0
170#define PA_CHANNEL_POSITION_AUX1 PA_CHANNEL_POSITION_AUX1
171#define PA_CHANNEL_POSITION_AUX2 PA_CHANNEL_POSITION_AUX2
172#define PA_CHANNEL_POSITION_AUX3 PA_CHANNEL_POSITION_AUX3
173#define PA_CHANNEL_POSITION_AUX4 PA_CHANNEL_POSITION_AUX4
174#define PA_CHANNEL_POSITION_AUX5 PA_CHANNEL_POSITION_AUX5
175#define PA_CHANNEL_POSITION_AUX6 PA_CHANNEL_POSITION_AUX6
176#define PA_CHANNEL_POSITION_AUX7 PA_CHANNEL_POSITION_AUX7
177#define PA_CHANNEL_POSITION_AUX8 PA_CHANNEL_POSITION_AUX8
178#define PA_CHANNEL_POSITION_AUX9 PA_CHANNEL_POSITION_AUX9
179#define PA_CHANNEL_POSITION_AUX10 PA_CHANNEL_POSITION_AUX10
180#define PA_CHANNEL_POSITION_AUX11 PA_CHANNEL_POSITION_AUX11
181#define PA_CHANNEL_POSITION_AUX12 PA_CHANNEL_POSITION_AUX12
182#define PA_CHANNEL_POSITION_AUX13 PA_CHANNEL_POSITION_AUX13
183#define PA_CHANNEL_POSITION_AUX14 PA_CHANNEL_POSITION_AUX14
184#define PA_CHANNEL_POSITION_AUX15 PA_CHANNEL_POSITION_AUX15
185#define PA_CHANNEL_POSITION_AUX16 PA_CHANNEL_POSITION_AUX16
186#define PA_CHANNEL_POSITION_AUX17 PA_CHANNEL_POSITION_AUX17
187#define PA_CHANNEL_POSITION_AUX18 PA_CHANNEL_POSITION_AUX18
188#define PA_CHANNEL_POSITION_AUX19 PA_CHANNEL_POSITION_AUX19
189#define PA_CHANNEL_POSITION_AUX20 PA_CHANNEL_POSITION_AUX20
190#define PA_CHANNEL_POSITION_AUX21 PA_CHANNEL_POSITION_AUX21
191#define PA_CHANNEL_POSITION_AUX22 PA_CHANNEL_POSITION_AUX22
192#define PA_CHANNEL_POSITION_AUX23 PA_CHANNEL_POSITION_AUX23
193#define PA_CHANNEL_POSITION_AUX24 PA_CHANNEL_POSITION_AUX24
194#define PA_CHANNEL_POSITION_AUX25 PA_CHANNEL_POSITION_AUX25
195#define PA_CHANNEL_POSITION_AUX26 PA_CHANNEL_POSITION_AUX26
196#define PA_CHANNEL_POSITION_AUX27 PA_CHANNEL_POSITION_AUX27
197#define PA_CHANNEL_POSITION_AUX28 PA_CHANNEL_POSITION_AUX28
198#define PA_CHANNEL_POSITION_AUX29 PA_CHANNEL_POSITION_AUX29
199#define PA_CHANNEL_POSITION_AUX30 PA_CHANNEL_POSITION_AUX30
200#define PA_CHANNEL_POSITION_AUX31 PA_CHANNEL_POSITION_AUX31
201#define PA_CHANNEL_POSITION_TOP_CENTER PA_CHANNEL_POSITION_TOP_CENTER
202#define PA_CHANNEL_POSITION_TOP_FRONT_LEFT PA_CHANNEL_POSITION_TOP_FRONT_LEFT
203#define PA_CHANNEL_POSITION_TOP_FRONT_RIGHT PA_CHANNEL_POSITION_TOP_FRONT_RIGHT
204#define PA_CHANNEL_POSITION_TOP_FRONT_CENTER PA_CHANNEL_POSITION_TOP_FRONT_CENTER
205#define PA_CHANNEL_POSITION_TOP_REAR_LEFT PA_CHANNEL_POSITION_TOP_REAR_LEFT
206#define PA_CHANNEL_POSITION_TOP_REAR_RIGHT PA_CHANNEL_POSITION_TOP_REAR_RIGHT
207#define PA_CHANNEL_POSITION_TOP_REAR_CENTER PA_CHANNEL_POSITION_TOP_REAR_CENTER
208#define PA_CHANNEL_POSITION_MAX PA_CHANNEL_POSITION_MAX
209/** \endcond */
210
211/** A mask of channel positions. \since 0.9.16 */
212typedef uint64_t pa_channel_position_mask_t;
213
214/** Makes a bit mask from a channel position. \since 0.9.16 */
215#define PA_CHANNEL_POSITION_MASK(f) ((pa_channel_position_mask_t) (1ULL << (f)))
216
217/** A list of channel mapping definitions for pa_channel_map_init_auto() */
218typedef enum pa_channel_map_def {
219 PA_CHANNEL_MAP_AIFF,
220 /**< The mapping from RFC3551, which is based on AIFF-C */
221
222/** \cond fulldocs */
223 PA_CHANNEL_MAP_ALSA,
224 /**< The default mapping used by ALSA. This mapping is probably
225 * not too useful since ALSA's default channel mapping depends on
226 * the device string used. */
227/** \endcond */
228
229 PA_CHANNEL_MAP_AUX,
230 /**< Only aux channels */
231
232 PA_CHANNEL_MAP_WAVEEX,
233 /**< Microsoft's WAVEFORMATEXTENSIBLE mapping. This mapping works
234 * as if all LSBs of dwChannelMask are set. */
235
236/** \cond fulldocs */
237 PA_CHANNEL_MAP_OSS,
238 /**< The default channel mapping used by OSS as defined in the OSS
239 * 4.0 API specs. This mapping is probably not too useful since
240 * the OSS API has changed in this respect and no longer knows a
241 * default channel mapping based on the number of channels. */
242/** \endcond */
243
244 /**< Upper limit of valid channel mapping definitions */
245 PA_CHANNEL_MAP_DEF_MAX,
246
247 PA_CHANNEL_MAP_DEFAULT = PA_CHANNEL_MAP_AIFF
248 /**< The default channel map */
249} pa_channel_map_def_t;
250
251/** \cond fulldocs */
252#define PA_CHANNEL_MAP_AIFF PA_CHANNEL_MAP_AIFF
253#define PA_CHANNEL_MAP_ALSA PA_CHANNEL_MAP_ALSA
254#define PA_CHANNEL_MAP_AUX PA_CHANNEL_MAP_AUX
255#define PA_CHANNEL_MAP_WAVEEX PA_CHANNEL_MAP_WAVEEX
256#define PA_CHANNEL_MAP_OSS PA_CHANNEL_MAP_OSS
257#define PA_CHANNEL_MAP_DEF_MAX PA_CHANNEL_MAP_DEF_MAX
258#define PA_CHANNEL_MAP_DEFAULT PA_CHANNEL_MAP_DEFAULT
259/** \endcond */
260
261/** A channel map which can be used to attach labels to specific
262 * channels of a stream. These values are relevant for conversion and
263 * mixing of streams */
264typedef struct pa_channel_map {
265 uint8_t channels;
266 /**< Number of channels mapped */
267
268 pa_channel_position_t map[PA_CHANNELS_MAX];
269 /**< Channel labels */
270} pa_channel_map;
271
272/** Initialize the specified channel map and return a pointer to
273 * it. The channel map will have a defined state but
274 * pa_channel_map_valid() will fail for it. */
275pa_channel_map* pa_channel_map_init(pa_channel_map *m);
276
277/** Initialize the specified channel map for monaural audio and return a pointer to it */
278pa_channel_map* pa_channel_map_init_mono(pa_channel_map *m);
279
280/** Initialize the specified channel map for stereophonic audio and return a pointer to it */
281pa_channel_map* pa_channel_map_init_stereo(pa_channel_map *m);
282
283/** Initialize the specified channel map for the specified number of
284 * channels using default labels and return a pointer to it. This call
285 * will fail (return NULL) if there is no default channel map known for this
286 * specific number of channels and mapping. */
287pa_channel_map* pa_channel_map_init_auto(pa_channel_map *m, unsigned channels, pa_channel_map_def_t def);
288
289/** Similar to pa_channel_map_init_auto() but instead of failing if no
290 * default mapping is known with the specified parameters it will
291 * synthesize a mapping based on a known mapping with fewer channels
292 * and fill up the rest with AUX0...AUX31 channels \since 0.9.11 */
293pa_channel_map* pa_channel_map_init_extend(pa_channel_map *m, unsigned channels, pa_channel_map_def_t def);
294
295/** Return a text label for the specified channel position */
296const char* pa_channel_position_to_string(pa_channel_position_t pos) PA_GCC_PURE;
297
298/** The inverse of pa_channel_position_to_string(). \since 0.9.16 */
299pa_channel_position_t pa_channel_position_from_string(const char *s) PA_GCC_PURE;
300
301/** Return a human readable text label for the specified channel position. \since 0.9.7 */
302const char* pa_channel_position_to_pretty_string(pa_channel_position_t pos);
303
304/** The maximum length of strings returned by
305 * pa_channel_map_snprint(). Please note that this value can change
306 * with any release without warning and without being considered API
307 * or ABI breakage. You should not use this definition anywhere where
308 * it might become part of an ABI. */
309#define PA_CHANNEL_MAP_SNPRINT_MAX 336
310
311/** Make a human readable string from the specified channel map. Returns \a s. */
312char* pa_channel_map_snprint(char *s, size_t l, const pa_channel_map *map);
313
314/** Parse a channel position list or well-known mapping name into a
315 * channel map structure. This turns the output of
316 * pa_channel_map_snprint() and pa_channel_map_to_name() back into a
317 * pa_channel_map */
318pa_channel_map *pa_channel_map_parse(pa_channel_map *map, const char *s);
319
320/** Compare two channel maps. Return 1 if both match. */
321int pa_channel_map_equal(const pa_channel_map *a, const pa_channel_map *b) PA_GCC_PURE;
322
323/** Return non-zero if the specified channel map is considered valid */
324int pa_channel_map_valid(const pa_channel_map *map) PA_GCC_PURE;
325
326/** Return non-zero if the specified channel map is compatible with
327 * the specified sample spec. \since 0.9.12 */
328int pa_channel_map_compatible(const pa_channel_map *map, const pa_sample_spec *ss) PA_GCC_PURE;
329
330/** Returns non-zero if every channel defined in b is also defined in a. \since 0.9.15 */
331int pa_channel_map_superset(const pa_channel_map *a, const pa_channel_map *b) PA_GCC_PURE;
332
333/** Returns non-zero if it makes sense to apply a volume 'balance'
334 * with this mapping, i.e.\ if there are left/right channels
335 * available. \since 0.9.15 */
336int pa_channel_map_can_balance(const pa_channel_map *map) PA_GCC_PURE;
337
338/** Returns non-zero if it makes sense to apply a volume 'fade'
339 * (i.e.\ 'balance' between front and rear) with this mapping, i.e.\ if
340 * there are front/rear channels available. \since 0.9.15 */
341int pa_channel_map_can_fade(const pa_channel_map *map) PA_GCC_PURE;
342
343/** Returns non-zero if it makes sense to apply a volume 'lfe balance'
344 * (i.e.\ 'balance' between LFE and non-LFE channels) with this mapping,
345 * i.e.\ if there are LFE and non-LFE channels available. \since 8.0 */
346int pa_channel_map_can_lfe_balance(const pa_channel_map *map) PA_GCC_PURE;
347
348/** Tries to find a well-known channel mapping name for this channel
349 * mapping, i.e.\ "stereo", "surround-71" and so on. If the channel
350 * mapping is unknown NULL will be returned. This name can be parsed
351 * with pa_channel_map_parse() \since 0.9.15 */
352const char* pa_channel_map_to_name(const pa_channel_map *map) PA_GCC_PURE;
353
354/** Tries to find a human readable text label for this channel
355mapping, i.e.\ "Stereo", "Surround 7.1" and so on. If the channel
356mapping is unknown NULL will be returned. \since 0.9.15 */
357const char* pa_channel_map_to_pretty_name(const pa_channel_map *map) PA_GCC_PURE;
358
359/** Returns non-zero if the specified channel position is available at
360 * least once in the channel map. \since 0.9.16 */
361int pa_channel_map_has_position(const pa_channel_map *map, pa_channel_position_t p) PA_GCC_PURE;
362
363/** Generates a bit mask from a channel map. \since 0.9.16 */
364pa_channel_position_mask_t pa_channel_map_mask(const pa_channel_map *map) PA_GCC_PURE;
365
366PA_C_DECL_END
367
368#endif
369

source code of include/pulse/channelmap.h