1 #ifndef foovolumehfoo 2 #define foovolumehfoo 3 4 /*** 5 This file is part of PulseAudio. 6 7 Copyright 2004-2006 Lennart Poettering 8 Copyright 2006 Pierre Ossman <ossman (at) 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 <inttypes.h> 27 #include <limits.h> 28 29 #include <pulse/cdecl.h> 30 #include <pulse/gccmacro.h> 31 #include <pulse/sample.h> 32 #include <pulse/channelmap.h> 33 #include <pulse/version.h> 34 35 /** \page volume Volume Control 36 * 37 * \section overv_sec Overview 38 * 39 * Sinks, sources, sink inputs and samples can all have their own volumes. 40 * To deal with these, The PulseAudio libray contains a number of functions 41 * that ease handling. 42 * 43 * The basic volume type in PulseAudio is the \ref pa_volume_t type. Most of 44 * the time, applications will use the aggregated pa_cvolume structure that 45 * can store the volume of all channels at once. 46 * 47 * Volumes commonly span between muted (0%), and normal (100%). It is possible 48 * to set volumes to higher than 100%, but clipping might occur. 49 * 50 * \section calc_sec Calculations 51 * 52 * The volumes in PulseAudio are logarithmic in nature and applications 53 * shouldn't perform calculations with them directly. Instead, they should 54 * be converted to and from either dB or a linear scale: 55 * 56 * \li dB - pa_sw_volume_from_dB() / pa_sw_volume_to_dB() 57 * \li Linear - pa_sw_volume_from_linear() / pa_sw_volume_to_linear() 58 * 59 * For simple multiplication, pa_sw_volume_multiply() and 60 * pa_sw_cvolume_multiply() can be used. 61 * 62 * Calculations can only be reliably performed on software volumes 63 * as it is commonly unknown what scale hardware volumes relate to. 64 * 65 * The functions described above are only valid when used with 66 * software volumes. Hence it is usually a better idea to treat all 67 * volume values as opaque with a range from PA_VOLUME_MUTED (0%) to 68 * PA_VOLUME_NORM (100%) and to refrain from any calculations with 69 * them. 70 * 71 * \section conv_sec Convenience Functions 72 * 73 * To handle the pa_cvolume structure, the PulseAudio library provides a 74 * number of convenienc functions: 75 * 76 * \li pa_cvolume_valid() - Tests if a pa_cvolume structure is valid. 77 * \li pa_cvolume_equal() - Tests if two pa_cvolume structures are identical. 78 * \li pa_cvolume_channels_equal_to() - Tests if all channels of a pa_cvolume 79 * structure have a given volume. 80 * \li pa_cvolume_is_muted() - Tests if all channels of a pa_cvolume 81 * structure are muted. 82 * \li pa_cvolume_is_norm() - Tests if all channels of a pa_cvolume structure 83 * are at a normal volume. 84 * \li pa_cvolume_set() - Set all channels of a pa_cvolume structure to a 85 * certain volume. 86 * \li pa_cvolume_reset() - Set all channels of a pa_cvolume structure to a 87 * normal volume. 88 * \li pa_cvolume_mute() - Set all channels of a pa_cvolume structure to a 89 * muted volume. 90 * \li pa_cvolume_avg() - Return the average volume of all channels. 91 * \li pa_cvolume_snprint() - Pretty print a pa_cvolume structure. 92 */ 93 94 /** \file 95 * Constants and routines for volume handling */ 96 97 PA_C_DECL_BEGIN 98 99 /** Volume specification: 100 * PA_VOLUME_MUTED: silence; 101 * < PA_VOLUME_NORM: decreased volume; 102 * PA_VOLUME_NORM: normal volume; 103 * > PA_VOLUME_NORM: increased volume */ 104 typedef uint32_t pa_volume_t; 105 106 /** Normal volume (100%, 0 dB) */ 107 #define PA_VOLUME_NORM ((pa_volume_t) 0x10000U) 108 109 /** Muted (minimal valid) volume (0%, -inf dB) */ 110 #define PA_VOLUME_MUTED ((pa_volume_t) 0U) 111 112 /** Maximum valid volume we can store. \since 0.9.15 */ 113 #define PA_VOLUME_MAX ((pa_volume_t) UINT32_MAX-1) 114 115 /** Special 'invalid' volume. \since 0.9.16 */ 116 #define PA_VOLUME_INVALID ((pa_volume_t) UINT32_MAX) 117 118 /** A structure encapsulating a per-channel volume */ 119 typedef struct pa_cvolume { 120 uint8_t channels; /**< Number of channels */ 121 pa_volume_t values[PA_CHANNELS_MAX]; /**< Per-channel volume */ 122 } pa_cvolume; 123 124 /** Return non-zero when *a == *b */ 125 int pa_cvolume_equal(const pa_cvolume *a, const pa_cvolume *b) PA_GCC_PURE; 126 127 /** Initialize the specified volume and return a pointer to 128 * it. The sample spec will have a defined state but 129 * pa_cvolume_valid() will fail for it. \since 0.9.13 */ 130 pa_cvolume* pa_cvolume_init(pa_cvolume *a); 131 132 /** Set the volume of all channels to PA_VOLUME_NORM */ 133 #define pa_cvolume_reset(a, n) pa_cvolume_set((a), (n), PA_VOLUME_NORM) 134 135 /** Set the volume of all channels to PA_VOLUME_MUTED */ 136 #define pa_cvolume_mute(a, n) pa_cvolume_set((a), (n), PA_VOLUME_MUTED) 137 138 /** Set the volume of all channels to the specified parameter */ 139 pa_cvolume* pa_cvolume_set(pa_cvolume *a, unsigned channels, pa_volume_t v); 140 141 /** Maximum length of the strings returned by 142 * pa_cvolume_snprint(). Please note that this value can change with 143 * any release without warning and without being considered API or ABI 144 * breakage. You should not use this definition anywhere where it 145 * might become part of an ABI.*/ 146 #define PA_CVOLUME_SNPRINT_MAX 320 147 148 /** Pretty print a volume structure */ 149 char *pa_cvolume_snprint(char *s, size_t l, const pa_cvolume *c); 150 151 /** Maximum length of the strings returned by 152 * pa_cvolume_snprint_dB(). Please note that this value can change with 153 * any release without warning and without being considered API or ABI 154 * breakage. You should not use this definition anywhere where it 155 * might become part of an ABI. \since 0.9.13 */ 156 #define PA_SW_CVOLUME_SNPRINT_DB_MAX 448 157 158 /** Pretty print a volume structure but show dB values. \since 0.9.13 */ 159 char *pa_sw_cvolume_snprint_dB(char *s, size_t l, const pa_cvolume *c); 160 161 /** Maximum length of the strings returned by 162 * pa_volume_snprint(). Please note that this value can change with 163 * any release without warning and without being considered API or ABI 164 * breakage. You should not use this definition anywhere where it 165 * might become part of an ABI. \since 0.9.15 */ 166 #define PA_VOLUME_SNPRINT_MAX 10 167 168 /** Pretty print a volume \since 0.9.15 */ 169 char *pa_volume_snprint(char *s, size_t l, pa_volume_t v); 170 171 /** Maximum length of the strings returned by 172 * pa_volume_snprint_dB(). Please note that this value can change with 173 * any release without warning and without being considered API or ABI 174 * breakage. You should not use this definition anywhere where it 175 * might become part of an ABI. \since 0.9.15 */ 176 #define PA_SW_VOLUME_SNPRINT_DB_MAX 10 177 178 /** Pretty print a volume but show dB values. \since 0.9.15 */ 179 char *pa_sw_volume_snprint_dB(char *s, size_t l, pa_volume_t v); 180 181 /** Return the average volume of all channels */ 182 pa_volume_t pa_cvolume_avg(const pa_cvolume *a) PA_GCC_PURE; 183 184 /** Return the average volume of all channels that are included in the 185 * specified channel map with the specified channel position mask. If 186 * cm is NULL this call is identical to pa_cvolume_avg(). If no 187 * channel is selected the returned value will be 188 * PA_VOLUME_MUTED. \since 0.9.16 */ 189 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; 190 191 /** Return the maximum volume of all channels. \since 0.9.12 */ 192 pa_volume_t pa_cvolume_max(const pa_cvolume *a) PA_GCC_PURE; 193 194 /** Return the maximum volume of all channels that are included in the 195 * specified channel map with the specified channel position mask. If 196 * cm is NULL this call is identical to pa_cvolume_max(). If no 197 * channel is selected the returned value will be PA_VOLUME_MUTED. 198 * \since 0.9.16 */ 199 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; 200 201 /** Return the minimum volume of all channels. \since 0.9.16 */ 202 pa_volume_t pa_cvolume_min(const pa_cvolume *a) PA_GCC_PURE; 203 204 /** Return the minimum volume of all channels that are included in the 205 * specified channel map with the specified channel position mask. If 206 * cm is NULL this call is identical to pa_cvolume_min(). If no 207 * channel is selected the returned value will be PA_VOLUME_MUTED. 208 * \since 0.9.16 */ 209 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; 210 211 /** Return TRUE when the passed cvolume structure is valid, FALSE otherwise */ 212 int pa_cvolume_valid(const pa_cvolume *v) PA_GCC_PURE; 213 214 /** Return non-zero if the volume of all channels is equal to the specified value */ 215 int pa_cvolume_channels_equal_to(const pa_cvolume *a, pa_volume_t v) PA_GCC_PURE; 216 217 /** Return 1 if the specified volume has all channels muted */ 218 #define pa_cvolume_is_muted(a) pa_cvolume_channels_equal_to((a), PA_VOLUME_MUTED) 219 220 /** Return 1 if the specified volume has all channels on normal level */ 221 #define pa_cvolume_is_norm(a) pa_cvolume_channels_equal_to((a), PA_VOLUME_NORM) 222 223 /** Multiply two volume specifications, return the result. This uses 224 * PA_VOLUME_NORM as neutral element of multiplication. This is only 225 * valid for software volumes! */ 226 pa_volume_t pa_sw_volume_multiply(pa_volume_t a, pa_volume_t b) PA_GCC_CONST; 227 228 /** Multiply two per-channel volumes and return the result in 229 * *dest. This is only valid for software volumes! a, b and dest may 230 * point to the same structure. */ 231 pa_cvolume *pa_sw_cvolume_multiply(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b); 232 233 /** Multiply a per-channel volume with a scalar volume and return the 234 * result in *dest. This is only valid for software volumes! a 235 * and dest may point to the same structure. \since 236 * 0.9.16 */ 237 pa_cvolume *pa_sw_cvolume_multiply_scalar(pa_cvolume *dest, const pa_cvolume *a, pa_volume_t b); 238 239 /** Divide two volume specifications, return the result. This uses 240 * PA_VOLUME_NORM as neutral element of division. This is only valid 241 * for software volumes! If a division by zero is tried the result 242 * will be 0. \since 0.9.13 */ 243 pa_volume_t pa_sw_volume_divide(pa_volume_t a, pa_volume_t b) PA_GCC_CONST; 244 245 /** Divide two per-channel volumes and return the result in 246 * *dest. This is only valid for software volumes! a, b 247 * and dest may point to the same structure. \since 0.9.13 */ 248 pa_cvolume *pa_sw_cvolume_divide(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b); 249 250 /** Divide a per-channel volume by a scalar volume and return the 251 * result in *dest. This is only valid for software volumes! a 252 * and dest may point to the same structure. \since 253 * 0.9.16 */ 254 pa_cvolume *pa_sw_cvolume_divide_scalar(pa_cvolume *dest, const pa_cvolume *a, pa_volume_t b); 255 256 /** Convert a decibel value to a volume (amplitude, not power). This is only valid for software volumes! */ 257 pa_volume_t pa_sw_volume_from_dB(double f) PA_GCC_CONST; 258 259 /** Convert a volume to a decibel value (amplitude, not power). This is only valid for software volumes! */ 260 double pa_sw_volume_to_dB(pa_volume_t v) PA_GCC_CONST; 261 262 /** Convert a linear factor to a volume. This is only valid for software volumes! */ 263 pa_volume_t pa_sw_volume_from_linear(double v) PA_GCC_CONST; 264 265 /** Convert a volume to a linear factor. This is only valid for software volumes! */ 266 double pa_sw_volume_to_linear(pa_volume_t v) PA_GCC_CONST; 267 268 #ifdef INFINITY 269 #define PA_DECIBEL_MININFTY ((double) -INFINITY) 270 #else 271 /** This floor value is used as minus infinity when using pa_volume_{to,from}_dB(). */ 272 #define PA_DECIBEL_MININFTY ((double) -200.0) 273 #endif 274 275 /** Remap a volume from one channel mapping to a different channel mapping. \since 0.9.12 */ 276 pa_cvolume *pa_cvolume_remap(pa_cvolume *v, const pa_channel_map *from, const pa_channel_map *to); 277 278 /** Return non-zero if the specified volume is compatible with the 279 * specified sample spec. \since 0.9.13 */ 280 int pa_cvolume_compatible(const pa_cvolume *v, const pa_sample_spec *ss) PA_GCC_PURE; 281 282 /** Return non-zero if the specified volume is compatible with the 283 * specified sample spec. \since 0.9.15 */ 284 int pa_cvolume_compatible_with_channel_map(const pa_cvolume *v, const pa_channel_map *cm) PA_GCC_PURE; 285 286 /** Calculate a 'balance' value for the specified volume with the 287 * specified channel map. The return value will range from -1.0f 288 * (left) to +1.0f (right). If no balance value is applicable to this 289 * channel map the return value will always be 0.0f. See 290 * pa_channel_map_can_balance(). \since 0.9.15 */ 291 float pa_cvolume_get_balance(const pa_cvolume *v, const pa_channel_map *map) PA_GCC_PURE; 292 293 /** Adjust the 'balance' value for the specified volume with the 294 * specified channel map. v will be modified in place and 295 * returned. The balance is a value between -1.0f and +1.0f. This 296 * operation might not be reversible! Also, after this call 297 * pa_cvolume_get_balance() is not guaranteed to actually return the 298 * requested balance value (e.g. when the input volume was zero anyway for 299 * all channels). If no balance value is applicable to 300 * this channel map the volume will not be modified. See 301 * pa_channel_map_can_balance(). \since 0.9.15 */ 302 pa_cvolume* pa_cvolume_set_balance(pa_cvolume *v, const pa_channel_map *map, float new_balance); 303 304 /** Calculate a 'fade' value (i.e. 'balance' between front and rear) 305 * for the specified volume with the specified channel map. The return 306 * value will range from -1.0f (rear) to +1.0f (left). If no fade 307 * value is applicable to this channel map the return value will 308 * always be 0.0f. See pa_channel_map_can_fade(). \since 0.9.15 */ 309 float pa_cvolume_get_fade(const pa_cvolume *v, const pa_channel_map *map) PA_GCC_PURE; 310 311 /** Adjust the 'fade' value (i.e. 'balance' between front and rear) 312 * for the specified volume with the specified channel map. v will be 313 * modified in place and returned. The balance is a value between 314 * -1.0f and +1.0f. This operation might not be reversible! Also, 315 * after this call pa_cvolume_get_fade() is not guaranteed to actually 316 * return the requested fade value (e.g. when the input volume was 317 * zero anyway for all channels). If no fade value is applicable to 318 * this channel map the volume will not be modified. See 319 * pa_channel_map_can_fade(). \since 0.9.15 */ 320 pa_cvolume* pa_cvolume_set_fade(pa_cvolume *v, const pa_channel_map *map, float new_fade); 321 322 /** Scale the passed pa_cvolume structure so that the maximum volume 323 * of all channels equals max. The proportions between the channel 324 * volumes are kept. \since 0.9.15 */ 325 pa_cvolume* pa_cvolume_scale(pa_cvolume *v, pa_volume_t max); 326 327 /** Scale the passed pa_cvolume structure so that the maximum volume 328 * of all channels selected via cm/mask equals max. This also modifies 329 * the volume of those channels that are unmasked. The proportions 330 * between the channel volumes are kept. \since 0.9.16 */ 331 pa_cvolume* pa_cvolume_scale_mask(pa_cvolume *v, pa_volume_t max, pa_channel_map *cm, pa_channel_position_mask_t mask); 332 333 /** Set the passed volume to all channels at the specified channel 334 * position. Will return the updated volume struct, or NULL if there 335 * is no channel at the position specified. You can check if a channel 336 * map includes a specific position by calling 337 * pa_channel_map_has_position(). \since 0.9.16 */ 338 pa_cvolume* pa_cvolume_set_position(pa_cvolume *cv, const pa_channel_map *map, pa_channel_position_t t, pa_volume_t v); 339 340 /** Get the maximum volume of all channels at the specified channel 341 * position. Will return 0 if there is no channel at the position 342 * specified. You can check if a channel map includes a specific 343 * position by calling pa_channel_map_has_position(). \since 0.9.16 */ 344 pa_volume_t pa_cvolume_get_position(pa_cvolume *cv, const pa_channel_map *map, pa_channel_position_t t) PA_GCC_PURE; 345 346 /** This goes through all channels in a and b and sets the 347 * corresponding channel in dest to the greater volume of both. a, b 348 * and dest may point to the same structure. \since 0.9.16 */ 349 pa_cvolume* pa_cvolume_merge(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b); 350 351 /** Increase the volume passed in by 'inc'. The proportions between 352 * the channels are kept. \since 0.9.16 */ 353 pa_cvolume* pa_cvolume_inc(pa_cvolume *v, pa_volume_t inc); 354 355 /** Increase the volume passed in by 'inc'. The proportions between 356 * the channels are kept. \since 0.9.16 */ 357 pa_cvolume* pa_cvolume_dec(pa_cvolume *v, pa_volume_t dec); 358 359 PA_C_DECL_END 360 361 #endif 362
