summaryrefslogtreecommitdiffstats
path: root/src/pulse/volume.h
blob: 349ca49f411c9c1440e05b36d59a6a93d0cfe4b7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
#ifndef foovolumehfoo
#define foovolumehfoo

/***
  This file is part of PulseAudio.

  Copyright 2004-2006 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 2.1 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 <inttypes.h>
#include <limits.h>

#include <pulse/cdecl.h>
#include <pulse/gccmacro.h>
#include <pulse/sample.h>
#include <pulse/channelmap.h>
#include <pulse/version.h>

/** \page volume Volume Control
 *
 * \section overv_sec Overview
 *
 * Sinks, sources, sink inputs and samples can all have their own volumes.
 * To deal with these, The PulseAudio libray contains a number of functions
 * that ease handling.
 *
 * The basic volume type in PulseAudio is the \ref pa_volume_t type. Most of
 * the time, applications will use the aggregated pa_cvolume structure that
 * can store the volume of all channels at once.
 *
 * Volumes commonly span between muted (0%), and normal (100%). It is possible
 * to set volumes to higher than 100%, but clipping might occur.
 *
 * \section calc_sec Calculations
 *
 * The volumes in PulseAudio are logarithmic in nature and applications
 * shouldn't perform calculations with them directly. Instead, they should
 * be converted to and from either dB or a linear scale:
 *
 * \li dB - pa_sw_volume_from_dB() / pa_sw_volume_to_dB()
 * \li Linear - pa_sw_volume_from_linear() / pa_sw_volume_to_linear()
 *
 * For simple multiplication, pa_sw_volume_multiply() and
 * pa_sw_cvolume_multiply() can be used.
 *
 * Calculations can only be reliably performed on software volumes
 * as it is commonly unknown what scale hardware volumes relate to.
 *
 * The functions described above are only valid when used with
 * software volumes. Hence it is usually a better idea to treat all
 * volume values as opaque with a range from PA_VOLUME_MUTED (0%) to
 * PA_VOLUME_NORM (100%) and to refrain from any calculations with
 * them.
 *
 * \section conv_sec Convenience Functions
 *
 * To handle the pa_cvolume structure, the PulseAudio library provides a
 * number of convenienc functions:
 *
 * \li pa_cvolume_valid() - Tests if a pa_cvolume structure is valid.
 * \li pa_cvolume_equal() - Tests if two pa_cvolume structures are identical.
 * \li pa_cvolume_channels_equal_to() - Tests if all channels of a pa_cvolume
 *                             structure have a given volume.
 * \li pa_cvolume_is_muted() - Tests if all channels of a pa_cvolume
 *                             structure are muted.
 * \li pa_cvolume_is_norm() - Tests if all channels of a pa_cvolume structure
 *                            are at a normal volume.
 * \li pa_cvolume_set() - Set all channels of a pa_cvolume structure to a
 *                        certain volume.
 * \li pa_cvolume_reset() - Set all channels of a pa_cvolume structure to a
 *                          normal volume.
 * \li pa_cvolume_mute() - Set all channels of a pa_cvolume structure to a
 *                         muted volume.
 * \li pa_cvolume_avg() - Return the average volume of all channels.
 * \li pa_cvolume_snprint() - Pretty print a pa_cvolume structure.
 */

/** \file
 * Constants and routines for volume handling */

PA_C_DECL_BEGIN

/** Volume specification:
 *  PA_VOLUME_MUTED: silence;
 * < PA_VOLUME_NORM: decreased volume;
 *   PA_VOLUME_NORM: normal volume;
 * > PA_VOLUME_NORM: increased volume */
typedef uint32_t pa_volume_t;

/** Normal volume (100%, 0 dB) */
#define PA_VOLUME_NORM ((pa_volume_t) 0x10000U)

/** Muted volume (0%, -inf dB) */
#define PA_VOLUME_MUTED ((pa_volume_t) 0U)

/** Maximum volume we can store. \since 0.9.15 */
#define PA_VOLUME_MAX ((pa_volume_t) UINT32_MAX)

/** A structure encapsulating a per-channel volume */
typedef struct pa_cvolume {
    uint8_t channels;                     /**< Number of channels */
    pa_volume_t values[PA_CHANNELS_MAX];  /**< Per-channel volume  */
} pa_cvolume;

/** Return non-zero when *a == *b */
int pa_cvolume_equal(const pa_cvolume *a, const pa_cvolume *b) PA_GCC_PURE;

/** Initialize the specified volume and return a pointer to
 * it. The sample spec will have a defined state but
 * pa_cvolume_valid() will fail for it. \since 0.9.13 */
pa_cvolume* pa_cvolume_init(pa_cvolume *a);

/** Set the volume of all channels to PA_VOLUME_NORM */
#define pa_cvolume_reset(a, n) pa_cvolume_set((a), (n), PA_VOLUME_NORM)

/** Set the volume of all channels to PA_VOLUME_MUTED */
#define pa_cvolume_mute(a, n) pa_cvolume_set((a), (n), PA_VOLUME_MUTED)

/** Set the volume of all channels to the specified parameter */
pa_cvolume* pa_cvolume_set(pa_cvolume *a, unsigned channels, pa_volume_t v);

/** Maximum length of the strings returned by
 * pa_cvolume_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_CVOLUME_SNPRINT_MAX 320

/** Pretty print a volume structure */
char *pa_cvolume_snprint(char *s, size_t l, const pa_cvolume *c);

/** Maximum length of the strings returned by
 * pa_cvolume_snprint_dB(). 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. \since 0.9.13 */
#define PA_SW_CVOLUME_SNPRINT_DB_MAX 448

/** Pretty print a volume structure but show dB values. \since 0.9.13 */
char *pa_sw_cvolume_snprint_dB(char *s, size_t l, const pa_cvolume *c);

/** Maximum length of the strings returned by
 * pa_volume_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. \since 0.9.15 */
#define PA_VOLUME_SNPRINT_MAX 10

/** Pretty print a volume \since 0.9.15 */
char *pa_volume_snprint(char *s, size_t l, pa_volume_t v);

/** Maximum length of the strings returned by
 * pa_volume_snprint_dB(). 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. \since 0.9.15 */
#define PA_SW_VOLUME_SNPRINT_DB_MAX 10

/** Pretty print a volume but show dB values. \since 0.9.15 */
char *pa_sw_volume_snprint_dB(char *s, size_t l, pa_volume_t v);

/** Return the average volume of all channels */
pa_volume_t pa_cvolume_avg(const pa_cvolume *a) PA_GCC_PURE;

/** Return the average volume of all channels that are included in the
 * specified channel map with the specified channel position mask. If
 * cm is NULL this call is identical to pa_cvolume_avg(). If no
 * channel is selected the returned value will be
 * PA_VOLUME_MUTED. \since 0.9.16 */
pa_volume_t pa_cvolume_avg_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) PA_GCC_PURE;

/** Return the maximum volume of all channels. \since 0.9.12 */
pa_volume_t pa_cvolume_max(const pa_cvolume *a) PA_GCC_PURE;

/** Return the maximum volume of all channels that are included in the
 * specified channel map with the specified channel position mask. If
 * cm is NULL this call is identical to pa_cvolume_max(). If no
 * channel is selected the returned value will be PA_VOLUME_MUTED.
 * \since 0.9.16 */
pa_volume_t pa_cvolume_max_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) PA_GCC_PURE;

/** Return the minimum volume of all channels. \since 0.9.16 */
pa_volume_t pa_cvolume_min(const pa_cvolume *a) PA_GCC_PURE;

/** Return the minimum volume of all channels that are included in the
 * specified channel map with the specified channel position mask. If
 * cm is NULL this call is identical to pa_cvolume_min(). If no
 * channel is selected the returned value will be PA_VOLUME_MUTED.
 * \since 0.9.16 */
pa_volume_t pa_cvolume_min_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) PA_GCC_PURE;

/** Return TRUE when the passed cvolume structure is valid, FALSE otherwise */
int pa_cvolume_valid(const pa_cvolume *v) PA_GCC_PURE;

/** Return non-zero if the volume of all channels is equal to the specified value */
int pa_cvolume_channels_equal_to(const pa_cvolume *a, pa_volume_t v) PA_GCC_PURE;

/** Return 1 if the specified volume has all channels muted */
#define pa_cvolume_is_muted(a) pa_cvolume_channels_equal_to((a), PA_VOLUME_MUTED)

/** Return 1 if the specified volume has all channels on normal level */
#define pa_cvolume_is_norm(a) pa_cvolume_channels_equal_to((a), PA_VOLUME_NORM)

/** Multiply two volume specifications, return the result. This uses
 * PA_VOLUME_NORM as neutral element of multiplication. This is only
 * valid for software volumes! */
pa_volume_t pa_sw_volume_multiply(pa_volume_t a, pa_volume_t b) PA_GCC_CONST;

/** Multiply two per-channel volumes and return the result in
 * *dest. This is only valid for software volumes! a, b and dest may
 * point to the same structure. */
pa_cvolume *pa_sw_cvolume_multiply(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b);

/** Multiply a per-channel volume with a scalar volume and return the
 * result in *dest. This is only valid for software volumes! a
 * and dest may point to the same structure. \since
 * 0.9.16 */
pa_cvolume *pa_sw_cvolume_multiply_scalar(pa_cvolume *dest, const pa_cvolume *a, pa_volume_t b);

/** Divide two volume specifications, return the result. This uses
 * PA_VOLUME_NORM as neutral element of division. This is only valid
 * for software volumes! If a division by zero is tried the result
 * will be 0. \since 0.9.13 */
pa_volume_t pa_sw_volume_divide(pa_volume_t a, pa_volume_t b) PA_GCC_CONST;

/** Divide two per-channel volumes and return the result in
 * *dest. This is only valid for software volumes! a, b
 * and dest may point to the same structure. \since 0.9.13 */
pa_cvolume *pa_sw_cvolume_divide(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b);

/** Divide a per-channel volume by a scalar volume and return the
 * result in *dest. This is only valid for software volumes! a
 * and dest may point to the same structure. \since
 * 0.9.16 */
pa_cvolume *pa_sw_cvolume_divide_scalar(pa_cvolume *dest, const pa_cvolume *a, pa_volume_t b);

/** Convert a decibel value to a volume (amplitude, not power). This is only valid for software volumes! */
pa_volume_t pa_sw_volume_from_dB(double f) PA_GCC_CONST;

/** Convert a volume to a decibel value (amplitude, not power). This is only valid for software volumes! */
double pa_sw_volume_to_dB(pa_volume_t v) PA_GCC_CONST;

/** Convert a linear factor to a volume. This is only valid for software volumes! */
pa_volume_t pa_sw_volume_from_linear(double v) PA_GCC_CONST;

/** Convert a volume to a linear factor. This is only valid for software volumes! */
double pa_sw_volume_to_linear(pa_volume_t v) PA_GCC_CONST;

#ifdef INFINITY
#define PA_DECIBEL_MININFTY ((double) -INFINITY)
#else
/** This floor value is used as minus infinity when using pa_volume_{to,from}_dB(). */
#define PA_DECIBEL_MININFTY ((double) -200.0)
#endif

/** Remap a volume from one channel mapping to a different channel mapping. \since 0.9.12 */
pa_cvolume *pa_cvolume_remap(pa_cvolume *v, const pa_channel_map *from, const pa_channel_map *to);

/** Return non-zero if the specified volume is compatible with the
 * specified sample spec. \since 0.9.13 */
int pa_cvolume_compatible(const pa_cvolume *v, const pa_sample_spec *ss) PA_GCC_PURE;

/** Return non-zero if the specified volume is compatible with the
 * specified sample spec. \since 0.9.15 */
int pa_cvolume_compatible_with_channel_map(const pa_cvolume *v, const pa_channel_map *cm) PA_GCC_PURE;

/** Calculate a 'balance' value for the specified volume with the
 * specified channel map. The return value will range from -1.0f
 * (left) to +1.0f (right). If no balance value is applicable to this
 * channel map the return value will always be 0.0f. See
 * pa_channel_map_can_balance(). \since 0.9.15 */
float pa_cvolume_get_balance(const pa_cvolume *v, const pa_channel_map *map) PA_GCC_PURE;

/** Adjust the 'balance' value for the specified volume with the
 * specified channel map. v will be modified in place and
 * returned. The balance is a value between -1.0f and +1.0f. This
 * operation might not be reversible! Also, after this call
 * pa_cvolume_get_balance() is not guaranteed to actually return the
 * requested balance value (e.g. when the input volume was zero anyway for
 * all channels). If no balance value is applicable to
 * this channel map the volume will not be modified. See
 * pa_channel_map_can_balance(). \since 0.9.15 */
pa_cvolume* pa_cvolume_set_balance(pa_cvolume *v, const pa_channel_map *map, float new_balance);

/** Calculate a 'fade' value (i.e. 'balance' between front and rear)
 * for the specified volume with the specified channel map. The return
 * value will range from -1.0f (rear) to +1.0f (left). If no fade
 * value is applicable to this channel map the return value will
 * always be 0.0f. See pa_channel_map_can_fade(). \since 0.9.15 */
float pa_cvolume_get_fade(const pa_cvolume *v, const pa_channel_map *map) PA_GCC_PURE;

/** Adjust the 'fade' value (i.e. 'balance' between front and rear)
 * for the specified volume with the specified channel map. v will be
 * modified in place and returned. The balance is a value between
 * -1.0f and +1.0f. This operation might not be reversible! Also,
 * after this call pa_cvolume_get_fade() is not guaranteed to actually
 * return the requested fade value (e.g. when the input volume was
 * zero anyway for all channels). If no fade value is applicable to
 * this channel map the volume will not be modified. See
 * pa_channel_map_can_fade(). \since 0.9.15 */
pa_cvolume* pa_cvolume_set_fade(pa_cvolume *v, const pa_channel_map *map, float new_fade);

/** Scale the passed pa_cvolume structure so that the maximum volume
 * of all channels equals max. The proportions between the channel
 * volumes are kept. \since 0.9.15 */
pa_cvolume* pa_cvolume_scale(pa_cvolume *v, pa_volume_t max);

/** Scale the passed pa_cvolume structure so that the maximum volume
 * of all channels selected via cm/mask equals max. This also modifies
 * the volume of those channels that are unmasked. The proportions
 * between the channel volumes are kept. \since 0.9.16 */
pa_cvolume* pa_cvolume_scale_mask(pa_cvolume *v, pa_volume_t max, pa_channel_map *cm, pa_channel_position_mask_t mask);

/** Set the passed volume to all channels at the specified channel
 * position. Will return the updated volume struct, or NULL if there
 * is no channel at the position specified. You can check if a channel
 * map includes a specific position by calling
 * pa_channel_map_has_position(). \since 0.9.16 */
pa_cvolume* pa_cvolume_set_position(pa_cvolume *cv, const pa_channel_map *map, pa_channel_position_t t, pa_volume_t v);

/** Get the maximum volume of all channels at the specified channel
 * position. Will return 0 if there is no channel at the position
 * specified. You can check if a channel map includes a specific
 * position by calling pa_channel_map_has_position(). \since 0.9.16 */
pa_volume_t pa_cvolume_get_position(pa_cvolume *cv, const pa_channel_map *map, pa_channel_position_t t) PA_GCC_PURE;

/** This goes through all channels in a and b and sets the
 * corresponding channel in dest to the greater volume of both. a, b
 * and dest may point to the same structure. \since 0.9.16 */
pa_cvolume* pa_cvolume_merge(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b);

PA_C_DECL_END

#endif