| 1 | /* |
|---|---|
| 2 | Simple DirectMedia Layer |
| 3 | Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org> |
| 4 | |
| 5 | This software is provided 'as-is', without any express or implied |
| 6 | warranty. In no event will the authors be held liable for any damages |
| 7 | arising from the use of this software. |
| 8 | |
| 9 | Permission is granted to anyone to use this software for any purpose, |
| 10 | including commercial applications, and to alter it and redistribute it |
| 11 | freely, subject to the following restrictions: |
| 12 | |
| 13 | 1. The origin of this software must not be misrepresented; you must not |
| 14 | claim that you wrote the original software. If you use this software |
| 15 | in a product, an acknowledgment in the product documentation would be |
| 16 | appreciated but is not required. |
| 17 | 2. Altered source versions must be plainly marked as such, and must not be |
| 18 | misrepresented as being the original software. |
| 19 | 3. This notice may not be removed or altered from any source distribution. |
| 20 | */ |
| 21 | |
| 22 | /** |
| 23 | * # CategoryAudio |
| 24 | * |
| 25 | * Audio functionality for the SDL library. |
| 26 | * |
| 27 | * All audio in SDL3 revolves around SDL_AudioStream. Whether you want to play |
| 28 | * or record audio, convert it, stream it, buffer it, or mix it, you're going |
| 29 | * to be passing it through an audio stream. |
| 30 | * |
| 31 | * Audio streams are quite flexible; they can accept any amount of data at a |
| 32 | * time, in any supported format, and output it as needed in any other format, |
| 33 | * even if the data format changes on either side halfway through. |
| 34 | * |
| 35 | * An app opens an audio device and binds any number of audio streams to it, |
| 36 | * feeding more data to the streams as available. When the device needs more |
| 37 | * data, it will pull it from all bound streams and mix them together for |
| 38 | * playback. |
| 39 | * |
| 40 | * Audio streams can also use an app-provided callback to supply data |
| 41 | * on-demand, which maps pretty closely to the SDL2 audio model. |
| 42 | * |
| 43 | * SDL also provides a simple .WAV loader in SDL_LoadWAV (and SDL_LoadWAV_IO |
| 44 | * if you aren't reading from a file) as a basic means to load sound data into |
| 45 | * your program. |
| 46 | * |
| 47 | * ## Logical audio devices |
| 48 | * |
| 49 | * In SDL3, opening a physical device (like a SoundBlaster 16 Pro) gives you a |
| 50 | * logical device ID that you can bind audio streams to. In almost all cases, |
| 51 | * logical devices can be used anywhere in the API that a physical device is |
| 52 | * normally used. However, since each device opening generates a new logical |
| 53 | * device, different parts of the program (say, a VoIP library, or |
| 54 | * text-to-speech framework, or maybe some other sort of mixer on top of SDL) |
| 55 | * can have their own device opens that do not interfere with each other; each |
| 56 | * logical device will mix its separate audio down to a single buffer, fed to |
| 57 | * the physical device, behind the scenes. As many logical devices as you like |
| 58 | * can come and go; SDL will only have to open the physical device at the OS |
| 59 | * level once, and will manage all the logical devices on top of it |
| 60 | * internally. |
| 61 | * |
| 62 | * One other benefit of logical devices: if you don't open a specific physical |
| 63 | * device, instead opting for the default, SDL can automatically migrate those |
| 64 | * logical devices to different hardware as circumstances change: a user |
| 65 | * plugged in headphones? The system default changed? SDL can transparently |
| 66 | * migrate the logical devices to the correct physical device seamlessly and |
| 67 | * keep playing; the app doesn't even have to know it happened if it doesn't |
| 68 | * want to. |
| 69 | * |
| 70 | * ## Simplified audio |
| 71 | * |
| 72 | * As a simplified model for when a single source of audio is all that's |
| 73 | * needed, an app can use SDL_OpenAudioDeviceStream, which is a single |
| 74 | * function to open an audio device, create an audio stream, bind that stream |
| 75 | * to the newly-opened device, and (optionally) provide a callback for |
| 76 | * obtaining audio data. When using this function, the primary interface is |
| 77 | * the SDL_AudioStream and the device handle is mostly hidden away; destroying |
| 78 | * a stream created through this function will also close the device, stream |
| 79 | * bindings cannot be changed, etc. One other quirk of this is that the device |
| 80 | * is started in a _paused_ state and must be explicitly resumed; this is |
| 81 | * partially to offer a clean migration for SDL2 apps and partially because |
| 82 | * the app might have to do more setup before playback begins; in the |
| 83 | * non-simplified form, nothing will play until a stream is bound to a device, |
| 84 | * so they start _unpaused_. |
| 85 | * |
| 86 | * ## Channel layouts |
| 87 | * |
| 88 | * Audio data passing through SDL is uncompressed PCM data, interleaved. One |
| 89 | * can provide their own decompression through an MP3, etc, decoder, but SDL |
| 90 | * does not provide this directly. Each interleaved channel of data is meant |
| 91 | * to be in a specific order. |
| 92 | * |
| 93 | * Abbreviations: |
| 94 | * |
| 95 | * - FRONT = single mono speaker |
| 96 | * - FL = front left speaker |
| 97 | * - FR = front right speaker |
| 98 | * - FC = front center speaker |
| 99 | * - BL = back left speaker |
| 100 | * - BR = back right speaker |
| 101 | * - SR = surround right speaker |
| 102 | * - SL = surround left speaker |
| 103 | * - BC = back center speaker |
| 104 | * - LFE = low-frequency speaker |
| 105 | * |
| 106 | * These are listed in the order they are laid out in memory, so "FL, FR" |
| 107 | * means "the front left speaker is laid out in memory first, then the front |
| 108 | * right, then it repeats for the next audio frame". |
| 109 | * |
| 110 | * - 1 channel (mono) layout: FRONT |
| 111 | * - 2 channels (stereo) layout: FL, FR |
| 112 | * - 3 channels (2.1) layout: FL, FR, LFE |
| 113 | * - 4 channels (quad) layout: FL, FR, BL, BR |
| 114 | * - 5 channels (4.1) layout: FL, FR, LFE, BL, BR |
| 115 | * - 6 channels (5.1) layout: FL, FR, FC, LFE, BL, BR (last two can also be |
| 116 | * SL, SR) |
| 117 | * - 7 channels (6.1) layout: FL, FR, FC, LFE, BC, SL, SR |
| 118 | * - 8 channels (7.1) layout: FL, FR, FC, LFE, BL, BR, SL, SR |
| 119 | * |
| 120 | * This is the same order as DirectSound expects, but applied to all |
| 121 | * platforms; SDL will swizzle the channels as necessary if a platform expects |
| 122 | * something different. |
| 123 | * |
| 124 | * SDL_AudioStream can also be provided channel maps to change this ordering |
| 125 | * to whatever is necessary, in other audio processing scenarios. |
| 126 | */ |
| 127 | |
| 128 | #ifndef SDL_audio_h_ |
| 129 | #define SDL_audio_h_ |
| 130 | |
| 131 | #include <SDL3/SDL_stdinc.h> |
| 132 | #include <SDL3/SDL_endian.h> |
| 133 | #include <SDL3/SDL_error.h> |
| 134 | #include <SDL3/SDL_mutex.h> |
| 135 | #include <SDL3/SDL_properties.h> |
| 136 | #include <SDL3/SDL_iostream.h> |
| 137 | |
| 138 | #include <SDL3/SDL_begin_code.h> |
| 139 | /* Set up for C function definitions, even when using C++ */ |
| 140 | #ifdef __cplusplus |
| 141 | extern "C"{ |
| 142 | #endif |
| 143 | |
| 144 | /** |
| 145 | * Mask of bits in an SDL_AudioFormat that contains the format bit size. |
| 146 | * |
| 147 | * Generally one should use SDL_AUDIO_BITSIZE instead of this macro directly. |
| 148 | * |
| 149 | * \since This macro is available since SDL 3.2.0. |
| 150 | */ |
| 151 | #define SDL_AUDIO_MASK_BITSIZE (0xFFu) |
| 152 | |
| 153 | /** |
| 154 | * Mask of bits in an SDL_AudioFormat that contain the floating point flag. |
| 155 | * |
| 156 | * Generally one should use SDL_AUDIO_ISFLOAT instead of this macro directly. |
| 157 | * |
| 158 | * \since This macro is available since SDL 3.2.0. |
| 159 | */ |
| 160 | #define SDL_AUDIO_MASK_FLOAT (1u<<8) |
| 161 | |
| 162 | /** |
| 163 | * Mask of bits in an SDL_AudioFormat that contain the bigendian flag. |
| 164 | * |
| 165 | * Generally one should use SDL_AUDIO_ISBIGENDIAN or SDL_AUDIO_ISLITTLEENDIAN |
| 166 | * instead of this macro directly. |
| 167 | * |
| 168 | * \since This macro is available since SDL 3.2.0. |
| 169 | */ |
| 170 | #define SDL_AUDIO_MASK_BIG_ENDIAN (1u<<12) |
| 171 | |
| 172 | /** |
| 173 | * Mask of bits in an SDL_AudioFormat that contain the signed data flag. |
| 174 | * |
| 175 | * Generally one should use SDL_AUDIO_ISSIGNED instead of this macro directly. |
| 176 | * |
| 177 | * \since This macro is available since SDL 3.2.0. |
| 178 | */ |
| 179 | #define SDL_AUDIO_MASK_SIGNED (1u<<15) |
| 180 | |
| 181 | /** |
| 182 | * Define an SDL_AudioFormat value. |
| 183 | * |
| 184 | * SDL does not support custom audio formats, so this macro is not of much use |
| 185 | * externally, but it can be illustrative as to what the various bits of an |
| 186 | * SDL_AudioFormat mean. |
| 187 | * |
| 188 | * For example, SDL_AUDIO_S32LE looks like this: |
| 189 | * |
| 190 | * ```c |
| 191 | * SDL_DEFINE_AUDIO_FORMAT(1, 0, 0, 32) |
| 192 | * ``` |
| 193 | * |
| 194 | * \param signed 1 for signed data, 0 for unsigned data. |
| 195 | * \param bigendian 1 for bigendian data, 0 for littleendian data. |
| 196 | * \param flt 1 for floating point data, 0 for integer data. |
| 197 | * \param size number of bits per sample. |
| 198 | * \returns a format value in the style of SDL_AudioFormat. |
| 199 | * |
| 200 | * \threadsafety It is safe to call this macro from any thread. |
| 201 | * |
| 202 | * \since This macro is available since SDL 3.2.0. |
| 203 | */ |
| 204 | #define SDL_DEFINE_AUDIO_FORMAT(signed, bigendian, flt, size) \ |
| 205 | (((Uint16)(signed) << 15) | ((Uint16)(bigendian) << 12) | ((Uint16)(flt) << 8) | ((size) & SDL_AUDIO_MASK_BITSIZE)) |
| 206 | |
| 207 | /** |
| 208 | * Audio format. |
| 209 | * |
| 210 | * \since This enum is available since SDL 3.2.0. |
| 211 | * |
| 212 | * \sa SDL_AUDIO_BITSIZE |
| 213 | * \sa SDL_AUDIO_BYTESIZE |
| 214 | * \sa SDL_AUDIO_ISINT |
| 215 | * \sa SDL_AUDIO_ISFLOAT |
| 216 | * \sa SDL_AUDIO_ISBIGENDIAN |
| 217 | * \sa SDL_AUDIO_ISLITTLEENDIAN |
| 218 | * \sa SDL_AUDIO_ISSIGNED |
| 219 | * \sa SDL_AUDIO_ISUNSIGNED |
| 220 | */ |
| 221 | typedef enum SDL_AudioFormat |
| 222 | { |
| 223 | SDL_AUDIO_UNKNOWN = 0x0000u, /**< Unspecified audio format */ |
| 224 | SDL_AUDIO_U8 = 0x0008u, /**< Unsigned 8-bit samples */ |
| 225 | /* SDL_DEFINE_AUDIO_FORMAT(0, 0, 0, 8), */ |
| 226 | SDL_AUDIO_S8 = 0x8008u, /**< Signed 8-bit samples */ |
| 227 | /* SDL_DEFINE_AUDIO_FORMAT(1, 0, 0, 8), */ |
| 228 | SDL_AUDIO_S16LE = 0x8010u, /**< Signed 16-bit samples */ |
| 229 | /* SDL_DEFINE_AUDIO_FORMAT(1, 0, 0, 16), */ |
| 230 | SDL_AUDIO_S16BE = 0x9010u, /**< As above, but big-endian byte order */ |
| 231 | /* SDL_DEFINE_AUDIO_FORMAT(1, 1, 0, 16), */ |
| 232 | SDL_AUDIO_S32LE = 0x8020u, /**< 32-bit integer samples */ |
| 233 | /* SDL_DEFINE_AUDIO_FORMAT(1, 0, 0, 32), */ |
| 234 | SDL_AUDIO_S32BE = 0x9020u, /**< As above, but big-endian byte order */ |
| 235 | /* SDL_DEFINE_AUDIO_FORMAT(1, 1, 0, 32), */ |
| 236 | SDL_AUDIO_F32LE = 0x8120u, /**< 32-bit floating point samples */ |
| 237 | /* SDL_DEFINE_AUDIO_FORMAT(1, 0, 1, 32), */ |
| 238 | SDL_AUDIO_F32BE = 0x9120u, /**< As above, but big-endian byte order */ |
| 239 | /* SDL_DEFINE_AUDIO_FORMAT(1, 1, 1, 32), */ |
| 240 | |
| 241 | /* These represent the current system's byteorder. */ |
| 242 | #if SDL_BYTEORDER == SDL_LIL_ENDIAN |
| 243 | SDL_AUDIO_S16 = SDL_AUDIO_S16LE, |
| 244 | SDL_AUDIO_S32 = SDL_AUDIO_S32LE, |
| 245 | SDL_AUDIO_F32 = SDL_AUDIO_F32LE |
| 246 | #else |
| 247 | SDL_AUDIO_S16 = SDL_AUDIO_S16BE, |
| 248 | SDL_AUDIO_S32 = SDL_AUDIO_S32BE, |
| 249 | SDL_AUDIO_F32 = SDL_AUDIO_F32BE |
| 250 | #endif |
| 251 | } SDL_AudioFormat; |
| 252 | |
| 253 | |
| 254 | /** |
| 255 | * Retrieve the size, in bits, from an SDL_AudioFormat. |
| 256 | * |
| 257 | * For example, `SDL_AUDIO_BITSIZE(SDL_AUDIO_S16)` returns 16. |
| 258 | * |
| 259 | * \param x an SDL_AudioFormat value. |
| 260 | * \returns data size in bits. |
| 261 | * |
| 262 | * \threadsafety It is safe to call this macro from any thread. |
| 263 | * |
| 264 | * \since This macro is available since SDL 3.2.0. |
| 265 | */ |
| 266 | #define SDL_AUDIO_BITSIZE(x) ((x) & SDL_AUDIO_MASK_BITSIZE) |
| 267 | |
| 268 | /** |
| 269 | * Retrieve the size, in bytes, from an SDL_AudioFormat. |
| 270 | * |
| 271 | * For example, `SDL_AUDIO_BYTESIZE(SDL_AUDIO_S16)` returns 2. |
| 272 | * |
| 273 | * \param x an SDL_AudioFormat value. |
| 274 | * \returns data size in bytes. |
| 275 | * |
| 276 | * \threadsafety It is safe to call this macro from any thread. |
| 277 | * |
| 278 | * \since This macro is available since SDL 3.2.0. |
| 279 | */ |
| 280 | #define SDL_AUDIO_BYTESIZE(x) (SDL_AUDIO_BITSIZE(x) / 8) |
| 281 | |
| 282 | /** |
| 283 | * Determine if an SDL_AudioFormat represents floating point data. |
| 284 | * |
| 285 | * For example, `SDL_AUDIO_ISFLOAT(SDL_AUDIO_S16)` returns 0. |
| 286 | * |
| 287 | * \param x an SDL_AudioFormat value. |
| 288 | * \returns non-zero if format is floating point, zero otherwise. |
| 289 | * |
| 290 | * \threadsafety It is safe to call this macro from any thread. |
| 291 | * |
| 292 | * \since This macro is available since SDL 3.2.0. |
| 293 | */ |
| 294 | #define SDL_AUDIO_ISFLOAT(x) ((x) & SDL_AUDIO_MASK_FLOAT) |
| 295 | |
| 296 | /** |
| 297 | * Determine if an SDL_AudioFormat represents bigendian data. |
| 298 | * |
| 299 | * For example, `SDL_AUDIO_ISBIGENDIAN(SDL_AUDIO_S16LE)` returns 0. |
| 300 | * |
| 301 | * \param x an SDL_AudioFormat value. |
| 302 | * \returns non-zero if format is bigendian, zero otherwise. |
| 303 | * |
| 304 | * \threadsafety It is safe to call this macro from any thread. |
| 305 | * |
| 306 | * \since This macro is available since SDL 3.2.0. |
| 307 | */ |
| 308 | #define SDL_AUDIO_ISBIGENDIAN(x) ((x) & SDL_AUDIO_MASK_BIG_ENDIAN) |
| 309 | |
| 310 | /** |
| 311 | * Determine if an SDL_AudioFormat represents littleendian data. |
| 312 | * |
| 313 | * For example, `SDL_AUDIO_ISLITTLEENDIAN(SDL_AUDIO_S16BE)` returns 0. |
| 314 | * |
| 315 | * \param x an SDL_AudioFormat value. |
| 316 | * \returns non-zero if format is littleendian, zero otherwise. |
| 317 | * |
| 318 | * \threadsafety It is safe to call this macro from any thread. |
| 319 | * |
| 320 | * \since This macro is available since SDL 3.2.0. |
| 321 | */ |
| 322 | #define SDL_AUDIO_ISLITTLEENDIAN(x) (!SDL_AUDIO_ISBIGENDIAN(x)) |
| 323 | |
| 324 | /** |
| 325 | * Determine if an SDL_AudioFormat represents signed data. |
| 326 | * |
| 327 | * For example, `SDL_AUDIO_ISSIGNED(SDL_AUDIO_U8)` returns 0. |
| 328 | * |
| 329 | * \param x an SDL_AudioFormat value. |
| 330 | * \returns non-zero if format is signed, zero otherwise. |
| 331 | * |
| 332 | * \threadsafety It is safe to call this macro from any thread. |
| 333 | * |
| 334 | * \since This macro is available since SDL 3.2.0. |
| 335 | */ |
| 336 | #define SDL_AUDIO_ISSIGNED(x) ((x) & SDL_AUDIO_MASK_SIGNED) |
| 337 | |
| 338 | /** |
| 339 | * Determine if an SDL_AudioFormat represents integer data. |
| 340 | * |
| 341 | * For example, `SDL_AUDIO_ISINT(SDL_AUDIO_F32)` returns 0. |
| 342 | * |
| 343 | * \param x an SDL_AudioFormat value. |
| 344 | * \returns non-zero if format is integer, zero otherwise. |
| 345 | * |
| 346 | * \threadsafety It is safe to call this macro from any thread. |
| 347 | * |
| 348 | * \since This macro is available since SDL 3.2.0. |
| 349 | */ |
| 350 | #define SDL_AUDIO_ISINT(x) (!SDL_AUDIO_ISFLOAT(x)) |
| 351 | |
| 352 | /** |
| 353 | * Determine if an SDL_AudioFormat represents unsigned data. |
| 354 | * |
| 355 | * For example, `SDL_AUDIO_ISUNSIGNED(SDL_AUDIO_S16)` returns 0. |
| 356 | * |
| 357 | * \param x an SDL_AudioFormat value. |
| 358 | * \returns non-zero if format is unsigned, zero otherwise. |
| 359 | * |
| 360 | * \threadsafety It is safe to call this macro from any thread. |
| 361 | * |
| 362 | * \since This macro is available since SDL 3.2.0. |
| 363 | */ |
| 364 | #define SDL_AUDIO_ISUNSIGNED(x) (!SDL_AUDIO_ISSIGNED(x)) |
| 365 | |
| 366 | |
| 367 | /** |
| 368 | * SDL Audio Device instance IDs. |
| 369 | * |
| 370 | * Zero is used to signify an invalid/null device. |
| 371 | * |
| 372 | * \since This datatype is available since SDL 3.2.0. |
| 373 | */ |
| 374 | typedef Uint32 SDL_AudioDeviceID; |
| 375 | |
| 376 | /** |
| 377 | * A value used to request a default playback audio device. |
| 378 | * |
| 379 | * Several functions that require an SDL_AudioDeviceID will accept this value |
| 380 | * to signify the app just wants the system to choose a default device instead |
| 381 | * of the app providing a specific one. |
| 382 | * |
| 383 | * \since This macro is available since SDL 3.2.0. |
| 384 | */ |
| 385 | #define SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK ((SDL_AudioDeviceID) 0xFFFFFFFFu) |
| 386 | |
| 387 | /** |
| 388 | * A value used to request a default recording audio device. |
| 389 | * |
| 390 | * Several functions that require an SDL_AudioDeviceID will accept this value |
| 391 | * to signify the app just wants the system to choose a default device instead |
| 392 | * of the app providing a specific one. |
| 393 | * |
| 394 | * \since This macro is available since SDL 3.2.0. |
| 395 | */ |
| 396 | #define SDL_AUDIO_DEVICE_DEFAULT_RECORDING ((SDL_AudioDeviceID) 0xFFFFFFFEu) |
| 397 | |
| 398 | /** |
| 399 | * Format specifier for audio data. |
| 400 | * |
| 401 | * \since This struct is available since SDL 3.2.0. |
| 402 | * |
| 403 | * \sa SDL_AudioFormat |
| 404 | */ |
| 405 | typedef struct SDL_AudioSpec |
| 406 | { |
| 407 | SDL_AudioFormat format; /**< Audio data format */ |
| 408 | int channels; /**< Number of channels: 1 mono, 2 stereo, etc */ |
| 409 | int freq; /**< sample rate: sample frames per second */ |
| 410 | } SDL_AudioSpec; |
| 411 | |
| 412 | /** |
| 413 | * Calculate the size of each audio frame (in bytes) from an SDL_AudioSpec. |
| 414 | * |
| 415 | * This reports on the size of an audio sample frame: stereo Sint16 data (2 |
| 416 | * channels of 2 bytes each) would be 4 bytes per frame, for example. |
| 417 | * |
| 418 | * \param x an SDL_AudioSpec to query. |
| 419 | * \returns the number of bytes used per sample frame. |
| 420 | * |
| 421 | * \threadsafety It is safe to call this macro from any thread. |
| 422 | * |
| 423 | * \since This macro is available since SDL 3.2.0. |
| 424 | */ |
| 425 | #define SDL_AUDIO_FRAMESIZE(x) (SDL_AUDIO_BYTESIZE((x).format) * (x).channels) |
| 426 | |
| 427 | /** |
| 428 | * The opaque handle that represents an audio stream. |
| 429 | * |
| 430 | * SDL_AudioStream is an audio conversion interface. |
| 431 | * |
| 432 | * - It can handle resampling data in chunks without generating artifacts, |
| 433 | * when it doesn't have the complete buffer available. |
| 434 | * - It can handle incoming data in any variable size. |
| 435 | * - It can handle input/output format changes on the fly. |
| 436 | * - It can remap audio channels between inputs and outputs. |
| 437 | * - You push data as you have it, and pull it when you need it |
| 438 | * - It can also function as a basic audio data queue even if you just have |
| 439 | * sound that needs to pass from one place to another. |
| 440 | * - You can hook callbacks up to them when more data is added or requested, |
| 441 | * to manage data on-the-fly. |
| 442 | * |
| 443 | * Audio streams are the core of the SDL3 audio interface. You create one or |
| 444 | * more of them, bind them to an opened audio device, and feed data to them |
| 445 | * (or for recording, consume data from them). |
| 446 | * |
| 447 | * \since This struct is available since SDL 3.2.0. |
| 448 | * |
| 449 | * \sa SDL_CreateAudioStream |
| 450 | */ |
| 451 | typedef struct SDL_AudioStream SDL_AudioStream; |
| 452 | |
| 453 | |
| 454 | /* Function prototypes */ |
| 455 | |
| 456 | /** |
| 457 | * Use this function to get the number of built-in audio drivers. |
| 458 | * |
| 459 | * This function returns a hardcoded number. This never returns a negative |
| 460 | * value; if there are no drivers compiled into this build of SDL, this |
| 461 | * function returns zero. The presence of a driver in this list does not mean |
| 462 | * it will function, it just means SDL is capable of interacting with that |
| 463 | * interface. For example, a build of SDL might have esound support, but if |
| 464 | * there's no esound server available, SDL's esound driver would fail if used. |
| 465 | * |
| 466 | * By default, SDL tries all drivers, in its preferred order, until one is |
| 467 | * found to be usable. |
| 468 | * |
| 469 | * \returns the number of built-in audio drivers. |
| 470 | * |
| 471 | * \threadsafety It is safe to call this function from any thread. |
| 472 | * |
| 473 | * \since This function is available since SDL 3.2.0. |
| 474 | * |
| 475 | * \sa SDL_GetAudioDriver |
| 476 | */ |
| 477 | extern SDL_DECLSPEC int SDLCALL SDL_GetNumAudioDrivers(void); |
| 478 | |
| 479 | /** |
| 480 | * Use this function to get the name of a built in audio driver. |
| 481 | * |
| 482 | * The list of audio drivers is given in the order that they are normally |
| 483 | * initialized by default; the drivers that seem more reasonable to choose |
| 484 | * first (as far as the SDL developers believe) are earlier in the list. |
| 485 | * |
| 486 | * The names of drivers are all simple, low-ASCII identifiers, like "alsa", |
| 487 | * "coreaudio" or "wasapi". These never have Unicode characters, and are not |
| 488 | * meant to be proper names. |
| 489 | * |
| 490 | * \param index the index of the audio driver; the value ranges from 0 to |
| 491 | * SDL_GetNumAudioDrivers() - 1. |
| 492 | * \returns the name of the audio driver at the requested index, or NULL if an |
| 493 | * invalid index was specified. |
| 494 | * |
| 495 | * \threadsafety It is safe to call this function from any thread. |
| 496 | * |
| 497 | * \since This function is available since SDL 3.2.0. |
| 498 | * |
| 499 | * \sa SDL_GetNumAudioDrivers |
| 500 | */ |
| 501 | extern SDL_DECLSPEC const char * SDLCALL SDL_GetAudioDriver(int index); |
| 502 | |
| 503 | /** |
| 504 | * Get the name of the current audio driver. |
| 505 | * |
| 506 | * The names of drivers are all simple, low-ASCII identifiers, like "alsa", |
| 507 | * "coreaudio" or "wasapi". These never have Unicode characters, and are not |
| 508 | * meant to be proper names. |
| 509 | * |
| 510 | * \returns the name of the current audio driver or NULL if no driver has been |
| 511 | * initialized. |
| 512 | * |
| 513 | * \threadsafety It is safe to call this function from any thread. |
| 514 | * |
| 515 | * \since This function is available since SDL 3.2.0. |
| 516 | */ |
| 517 | extern SDL_DECLSPEC const char * SDLCALL SDL_GetCurrentAudioDriver(void); |
| 518 | |
| 519 | /** |
| 520 | * Get a list of currently-connected audio playback devices. |
| 521 | * |
| 522 | * This returns of list of available devices that play sound, perhaps to |
| 523 | * speakers or headphones ("playback" devices). If you want devices that |
| 524 | * record audio, like a microphone ("recording" devices), use |
| 525 | * SDL_GetAudioRecordingDevices() instead. |
| 526 | * |
| 527 | * This only returns a list of physical devices; it will not have any device |
| 528 | * IDs returned by SDL_OpenAudioDevice(). |
| 529 | * |
| 530 | * If this function returns NULL, to signify an error, `*count` will be set to |
| 531 | * zero. |
| 532 | * |
| 533 | * \param count a pointer filled in with the number of devices returned, may |
| 534 | * be NULL. |
| 535 | * \returns a 0 terminated array of device instance IDs or NULL on error; call |
| 536 | * SDL_GetError() for more information. This should be freed with |
| 537 | * SDL_free() when it is no longer needed. |
| 538 | * |
| 539 | * \threadsafety It is safe to call this function from any thread. |
| 540 | * |
| 541 | * \since This function is available since SDL 3.2.0. |
| 542 | * |
| 543 | * \sa SDL_OpenAudioDevice |
| 544 | * \sa SDL_GetAudioRecordingDevices |
| 545 | */ |
| 546 | extern SDL_DECLSPEC SDL_AudioDeviceID * SDLCALL SDL_GetAudioPlaybackDevices(int *count); |
| 547 | |
| 548 | /** |
| 549 | * Get a list of currently-connected audio recording devices. |
| 550 | * |
| 551 | * This returns of list of available devices that record audio, like a |
| 552 | * microphone ("recording" devices). If you want devices that play sound, |
| 553 | * perhaps to speakers or headphones ("playback" devices), use |
| 554 | * SDL_GetAudioPlaybackDevices() instead. |
| 555 | * |
| 556 | * This only returns a list of physical devices; it will not have any device |
| 557 | * IDs returned by SDL_OpenAudioDevice(). |
| 558 | * |
| 559 | * If this function returns NULL, to signify an error, `*count` will be set to |
| 560 | * zero. |
| 561 | * |
| 562 | * \param count a pointer filled in with the number of devices returned, may |
| 563 | * be NULL. |
| 564 | * \returns a 0 terminated array of device instance IDs, or NULL on failure; |
| 565 | * call SDL_GetError() for more information. This should be freed |
| 566 | * with SDL_free() when it is no longer needed. |
| 567 | * |
| 568 | * \threadsafety It is safe to call this function from any thread. |
| 569 | * |
| 570 | * \since This function is available since SDL 3.2.0. |
| 571 | * |
| 572 | * \sa SDL_OpenAudioDevice |
| 573 | * \sa SDL_GetAudioPlaybackDevices |
| 574 | */ |
| 575 | extern SDL_DECLSPEC SDL_AudioDeviceID * SDLCALL SDL_GetAudioRecordingDevices(int *count); |
| 576 | |
| 577 | /** |
| 578 | * Get the human-readable name of a specific audio device. |
| 579 | * |
| 580 | * \param devid the instance ID of the device to query. |
| 581 | * \returns the name of the audio device, or NULL on failure; call |
| 582 | * SDL_GetError() for more information. |
| 583 | * |
| 584 | * \threadsafety It is safe to call this function from any thread. |
| 585 | * |
| 586 | * \since This function is available since SDL 3.2.0. |
| 587 | * |
| 588 | * \sa SDL_GetAudioPlaybackDevices |
| 589 | * \sa SDL_GetAudioRecordingDevices |
| 590 | */ |
| 591 | extern SDL_DECLSPEC const char * SDLCALL SDL_GetAudioDeviceName(SDL_AudioDeviceID devid); |
| 592 | |
| 593 | /** |
| 594 | * Get the current audio format of a specific audio device. |
| 595 | * |
| 596 | * For an opened device, this will report the format the device is currently |
| 597 | * using. If the device isn't yet opened, this will report the device's |
| 598 | * preferred format (or a reasonable default if this can't be determined). |
| 599 | * |
| 600 | * You may also specify SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK or |
| 601 | * SDL_AUDIO_DEVICE_DEFAULT_RECORDING here, which is useful for getting a |
| 602 | * reasonable recommendation before opening the system-recommended default |
| 603 | * device. |
| 604 | * |
| 605 | * You can also use this to request the current device buffer size. This is |
| 606 | * specified in sample frames and represents the amount of data SDL will feed |
| 607 | * to the physical hardware in each chunk. This can be converted to |
| 608 | * milliseconds of audio with the following equation: |
| 609 | * |
| 610 | * `ms = (int) ((((Sint64) frames) * 1000) / spec.freq);` |
| 611 | * |
| 612 | * Buffer size is only important if you need low-level control over the audio |
| 613 | * playback timing. Most apps do not need this. |
| 614 | * |
| 615 | * \param devid the instance ID of the device to query. |
| 616 | * \param spec on return, will be filled with device details. |
| 617 | * \param sample_frames pointer to store device buffer size, in sample frames. |
| 618 | * Can be NULL. |
| 619 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 620 | * information. |
| 621 | * |
| 622 | * \threadsafety It is safe to call this function from any thread. |
| 623 | * |
| 624 | * \since This function is available since SDL 3.2.0. |
| 625 | */ |
| 626 | extern SDL_DECLSPEC bool SDLCALL SDL_GetAudioDeviceFormat(SDL_AudioDeviceID devid, SDL_AudioSpec *spec, int *sample_frames); |
| 627 | |
| 628 | /** |
| 629 | * Get the current channel map of an audio device. |
| 630 | * |
| 631 | * Channel maps are optional; most things do not need them, instead passing |
| 632 | * data in the [order that SDL expects](CategoryAudio#channel-layouts). |
| 633 | * |
| 634 | * Audio devices usually have no remapping applied. This is represented by |
| 635 | * returning NULL, and does not signify an error. |
| 636 | * |
| 637 | * \param devid the instance ID of the device to query. |
| 638 | * \param count On output, set to number of channels in the map. Can be NULL. |
| 639 | * \returns an array of the current channel mapping, with as many elements as |
| 640 | * the current output spec's channels, or NULL if default. This |
| 641 | * should be freed with SDL_free() when it is no longer needed. |
| 642 | * |
| 643 | * \threadsafety It is safe to call this function from any thread. |
| 644 | * |
| 645 | * \since This function is available since SDL 3.2.0. |
| 646 | * |
| 647 | * \sa SDL_SetAudioStreamInputChannelMap |
| 648 | */ |
| 649 | extern SDL_DECLSPEC int * SDLCALL SDL_GetAudioDeviceChannelMap(SDL_AudioDeviceID devid, int *count); |
| 650 | |
| 651 | /** |
| 652 | * Open a specific audio device. |
| 653 | * |
| 654 | * You can open both playback and recording devices through this function. |
| 655 | * Playback devices will take data from bound audio streams, mix it, and send |
| 656 | * it to the hardware. Recording devices will feed any bound audio streams |
| 657 | * with a copy of any incoming data. |
| 658 | * |
| 659 | * An opened audio device starts out with no audio streams bound. To start |
| 660 | * audio playing, bind a stream and supply audio data to it. Unlike SDL2, |
| 661 | * there is no audio callback; you only bind audio streams and make sure they |
| 662 | * have data flowing into them (however, you can simulate SDL2's semantics |
| 663 | * fairly closely by using SDL_OpenAudioDeviceStream instead of this |
| 664 | * function). |
| 665 | * |
| 666 | * If you don't care about opening a specific device, pass a `devid` of either |
| 667 | * `SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK` or |
| 668 | * `SDL_AUDIO_DEVICE_DEFAULT_RECORDING`. In this case, SDL will try to pick |
| 669 | * the most reasonable default, and may also switch between physical devices |
| 670 | * seamlessly later, if the most reasonable default changes during the |
| 671 | * lifetime of this opened device (user changed the default in the OS's system |
| 672 | * preferences, the default got unplugged so the system jumped to a new |
| 673 | * default, the user plugged in headphones on a mobile device, etc). Unless |
| 674 | * you have a good reason to choose a specific device, this is probably what |
| 675 | * you want. |
| 676 | * |
| 677 | * You may request a specific format for the audio device, but there is no |
| 678 | * promise the device will honor that request for several reasons. As such, |
| 679 | * it's only meant to be a hint as to what data your app will provide. Audio |
| 680 | * streams will accept data in whatever format you specify and manage |
| 681 | * conversion for you as appropriate. SDL_GetAudioDeviceFormat can tell you |
| 682 | * the preferred format for the device before opening and the actual format |
| 683 | * the device is using after opening. |
| 684 | * |
| 685 | * It's legal to open the same device ID more than once; each successful open |
| 686 | * will generate a new logical SDL_AudioDeviceID that is managed separately |
| 687 | * from others on the same physical device. This allows libraries to open a |
| 688 | * device separately from the main app and bind its own streams without |
| 689 | * conflicting. |
| 690 | * |
| 691 | * It is also legal to open a device ID returned by a previous call to this |
| 692 | * function; doing so just creates another logical device on the same physical |
| 693 | * device. This may be useful for making logical groupings of audio streams. |
| 694 | * |
| 695 | * This function returns the opened device ID on success. This is a new, |
| 696 | * unique SDL_AudioDeviceID that represents a logical device. |
| 697 | * |
| 698 | * Some backends might offer arbitrary devices (for example, a networked audio |
| 699 | * protocol that can connect to an arbitrary server). For these, as a change |
| 700 | * from SDL2, you should open a default device ID and use an SDL hint to |
| 701 | * specify the target if you care, or otherwise let the backend figure out a |
| 702 | * reasonable default. Most backends don't offer anything like this, and often |
| 703 | * this would be an end user setting an environment variable for their custom |
| 704 | * need, and not something an application should specifically manage. |
| 705 | * |
| 706 | * When done with an audio device, possibly at the end of the app's life, one |
| 707 | * should call SDL_CloseAudioDevice() on the returned device id. |
| 708 | * |
| 709 | * \param devid the device instance id to open, or |
| 710 | * SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK or |
| 711 | * SDL_AUDIO_DEVICE_DEFAULT_RECORDING for the most reasonable |
| 712 | * default device. |
| 713 | * \param spec the requested device configuration. Can be NULL to use |
| 714 | * reasonable defaults. |
| 715 | * \returns the device ID on success or 0 on failure; call SDL_GetError() for |
| 716 | * more information. |
| 717 | * |
| 718 | * \threadsafety It is safe to call this function from any thread. |
| 719 | * |
| 720 | * \since This function is available since SDL 3.2.0. |
| 721 | * |
| 722 | * \sa SDL_CloseAudioDevice |
| 723 | * \sa SDL_GetAudioDeviceFormat |
| 724 | */ |
| 725 | extern SDL_DECLSPEC SDL_AudioDeviceID SDLCALL SDL_OpenAudioDevice(SDL_AudioDeviceID devid, const SDL_AudioSpec *spec); |
| 726 | |
| 727 | /** |
| 728 | * Determine if an audio device is physical (instead of logical). |
| 729 | * |
| 730 | * An SDL_AudioDeviceID that represents physical hardware is a physical |
| 731 | * device; there is one for each piece of hardware that SDL can see. Logical |
| 732 | * devices are created by calling SDL_OpenAudioDevice or |
| 733 | * SDL_OpenAudioDeviceStream, and while each is associated with a physical |
| 734 | * device, there can be any number of logical devices on one physical device. |
| 735 | * |
| 736 | * For the most part, logical and physical IDs are interchangeable--if you try |
| 737 | * to open a logical device, SDL understands to assign that effort to the |
| 738 | * underlying physical device, etc. However, it might be useful to know if an |
| 739 | * arbitrary device ID is physical or logical. This function reports which. |
| 740 | * |
| 741 | * This function may return either true or false for invalid device IDs. |
| 742 | * |
| 743 | * \param devid the device ID to query. |
| 744 | * \returns true if devid is a physical device, false if it is logical. |
| 745 | * |
| 746 | * \threadsafety It is safe to call this function from any thread. |
| 747 | * |
| 748 | * \since This function is available since SDL 3.2.0. |
| 749 | */ |
| 750 | extern SDL_DECLSPEC bool SDLCALL SDL_IsAudioDevicePhysical(SDL_AudioDeviceID devid); |
| 751 | |
| 752 | /** |
| 753 | * Determine if an audio device is a playback device (instead of recording). |
| 754 | * |
| 755 | * This function may return either true or false for invalid device IDs. |
| 756 | * |
| 757 | * \param devid the device ID to query. |
| 758 | * \returns true if devid is a playback device, false if it is recording. |
| 759 | * |
| 760 | * \threadsafety It is safe to call this function from any thread. |
| 761 | * |
| 762 | * \since This function is available since SDL 3.2.0. |
| 763 | */ |
| 764 | extern SDL_DECLSPEC bool SDLCALL SDL_IsAudioDevicePlayback(SDL_AudioDeviceID devid); |
| 765 | |
| 766 | /** |
| 767 | * Use this function to pause audio playback on a specified device. |
| 768 | * |
| 769 | * This function pauses audio processing for a given device. Any bound audio |
| 770 | * streams will not progress, and no audio will be generated. Pausing one |
| 771 | * device does not prevent other unpaused devices from running. |
| 772 | * |
| 773 | * Unlike in SDL2, audio devices start in an _unpaused_ state, since an app |
| 774 | * has to bind a stream before any audio will flow. Pausing a paused device is |
| 775 | * a legal no-op. |
| 776 | * |
| 777 | * Pausing a device can be useful to halt all audio without unbinding all the |
| 778 | * audio streams. This might be useful while a game is paused, or a level is |
| 779 | * loading, etc. |
| 780 | * |
| 781 | * Physical devices can not be paused or unpaused, only logical devices |
| 782 | * created through SDL_OpenAudioDevice() can be. |
| 783 | * |
| 784 | * \param devid a device opened by SDL_OpenAudioDevice(). |
| 785 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 786 | * information. |
| 787 | * |
| 788 | * \threadsafety It is safe to call this function from any thread. |
| 789 | * |
| 790 | * \since This function is available since SDL 3.2.0. |
| 791 | * |
| 792 | * \sa SDL_ResumeAudioDevice |
| 793 | * \sa SDL_AudioDevicePaused |
| 794 | */ |
| 795 | extern SDL_DECLSPEC bool SDLCALL SDL_PauseAudioDevice(SDL_AudioDeviceID devid); |
| 796 | |
| 797 | /** |
| 798 | * Use this function to unpause audio playback on a specified device. |
| 799 | * |
| 800 | * This function unpauses audio processing for a given device that has |
| 801 | * previously been paused with SDL_PauseAudioDevice(). Once unpaused, any |
| 802 | * bound audio streams will begin to progress again, and audio can be |
| 803 | * generated. |
| 804 | * |
| 805 | * Unlike in SDL2, audio devices start in an _unpaused_ state, since an app |
| 806 | * has to bind a stream before any audio will flow. Unpausing an unpaused |
| 807 | * device is a legal no-op. |
| 808 | * |
| 809 | * Physical devices can not be paused or unpaused, only logical devices |
| 810 | * created through SDL_OpenAudioDevice() can be. |
| 811 | * |
| 812 | * \param devid a device opened by SDL_OpenAudioDevice(). |
| 813 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 814 | * information. |
| 815 | * |
| 816 | * \threadsafety It is safe to call this function from any thread. |
| 817 | * |
| 818 | * \since This function is available since SDL 3.2.0. |
| 819 | * |
| 820 | * \sa SDL_AudioDevicePaused |
| 821 | * \sa SDL_PauseAudioDevice |
| 822 | */ |
| 823 | extern SDL_DECLSPEC bool SDLCALL SDL_ResumeAudioDevice(SDL_AudioDeviceID devid); |
| 824 | |
| 825 | /** |
| 826 | * Use this function to query if an audio device is paused. |
| 827 | * |
| 828 | * Unlike in SDL2, audio devices start in an _unpaused_ state, since an app |
| 829 | * has to bind a stream before any audio will flow. |
| 830 | * |
| 831 | * Physical devices can not be paused or unpaused, only logical devices |
| 832 | * created through SDL_OpenAudioDevice() can be. Physical and invalid device |
| 833 | * IDs will report themselves as unpaused here. |
| 834 | * |
| 835 | * \param devid a device opened by SDL_OpenAudioDevice(). |
| 836 | * \returns true if device is valid and paused, false otherwise. |
| 837 | * |
| 838 | * \threadsafety It is safe to call this function from any thread. |
| 839 | * |
| 840 | * \since This function is available since SDL 3.2.0. |
| 841 | * |
| 842 | * \sa SDL_PauseAudioDevice |
| 843 | * \sa SDL_ResumeAudioDevice |
| 844 | */ |
| 845 | extern SDL_DECLSPEC bool SDLCALL SDL_AudioDevicePaused(SDL_AudioDeviceID devid); |
| 846 | |
| 847 | /** |
| 848 | * Get the gain of an audio device. |
| 849 | * |
| 850 | * The gain of a device is its volume; a larger gain means a louder output, |
| 851 | * with a gain of zero being silence. |
| 852 | * |
| 853 | * Audio devices default to a gain of 1.0f (no change in output). |
| 854 | * |
| 855 | * Physical devices may not have their gain changed, only logical devices, and |
| 856 | * this function will always return -1.0f when used on physical devices. |
| 857 | * |
| 858 | * \param devid the audio device to query. |
| 859 | * \returns the gain of the device or -1.0f on failure; call SDL_GetError() |
| 860 | * for more information. |
| 861 | * |
| 862 | * \threadsafety It is safe to call this function from any thread. |
| 863 | * |
| 864 | * \since This function is available since SDL 3.2.0. |
| 865 | * |
| 866 | * \sa SDL_SetAudioDeviceGain |
| 867 | */ |
| 868 | extern SDL_DECLSPEC float SDLCALL SDL_GetAudioDeviceGain(SDL_AudioDeviceID devid); |
| 869 | |
| 870 | /** |
| 871 | * Change the gain of an audio device. |
| 872 | * |
| 873 | * The gain of a device is its volume; a larger gain means a louder output, |
| 874 | * with a gain of zero being silence. |
| 875 | * |
| 876 | * Audio devices default to a gain of 1.0f (no change in output). |
| 877 | * |
| 878 | * Physical devices may not have their gain changed, only logical devices, and |
| 879 | * this function will always return false when used on physical devices. While |
| 880 | * it might seem attractive to adjust several logical devices at once in this |
| 881 | * way, it would allow an app or library to interfere with another portion of |
| 882 | * the program's otherwise-isolated devices. |
| 883 | * |
| 884 | * This is applied, along with any per-audiostream gain, during playback to |
| 885 | * the hardware, and can be continuously changed to create various effects. On |
| 886 | * recording devices, this will adjust the gain before passing the data into |
| 887 | * an audiostream; that recording audiostream can then adjust its gain further |
| 888 | * when outputting the data elsewhere, if it likes, but that second gain is |
| 889 | * not applied until the data leaves the audiostream again. |
| 890 | * |
| 891 | * \param devid the audio device on which to change gain. |
| 892 | * \param gain the gain. 1.0f is no change, 0.0f is silence. |
| 893 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 894 | * information. |
| 895 | * |
| 896 | * \threadsafety It is safe to call this function from any thread, as it holds |
| 897 | * a stream-specific mutex while running. |
| 898 | * |
| 899 | * \since This function is available since SDL 3.2.0. |
| 900 | * |
| 901 | * \sa SDL_GetAudioDeviceGain |
| 902 | */ |
| 903 | extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioDeviceGain(SDL_AudioDeviceID devid, float gain); |
| 904 | |
| 905 | /** |
| 906 | * Close a previously-opened audio device. |
| 907 | * |
| 908 | * The application should close open audio devices once they are no longer |
| 909 | * needed. |
| 910 | * |
| 911 | * This function may block briefly while pending audio data is played by the |
| 912 | * hardware, so that applications don't drop the last buffer of data they |
| 913 | * supplied if terminating immediately afterwards. |
| 914 | * |
| 915 | * \param devid an audio device id previously returned by |
| 916 | * SDL_OpenAudioDevice(). |
| 917 | * |
| 918 | * \threadsafety It is safe to call this function from any thread. |
| 919 | * |
| 920 | * \since This function is available since SDL 3.2.0. |
| 921 | * |
| 922 | * \sa SDL_OpenAudioDevice |
| 923 | */ |
| 924 | extern SDL_DECLSPEC void SDLCALL SDL_CloseAudioDevice(SDL_AudioDeviceID devid); |
| 925 | |
| 926 | /** |
| 927 | * Bind a list of audio streams to an audio device. |
| 928 | * |
| 929 | * Audio data will flow through any bound streams. For a playback device, data |
| 930 | * for all bound streams will be mixed together and fed to the device. For a |
| 931 | * recording device, a copy of recorded data will be provided to each bound |
| 932 | * stream. |
| 933 | * |
| 934 | * Audio streams can only be bound to an open device. This operation is |
| 935 | * atomic--all streams bound in the same call will start processing at the |
| 936 | * same time, so they can stay in sync. Also: either all streams will be bound |
| 937 | * or none of them will be. |
| 938 | * |
| 939 | * It is an error to bind an already-bound stream; it must be explicitly |
| 940 | * unbound first. |
| 941 | * |
| 942 | * Binding a stream to a device will set its output format for playback |
| 943 | * devices, and its input format for recording devices, so they match the |
| 944 | * device's settings. The caller is welcome to change the other end of the |
| 945 | * stream's format at any time with SDL_SetAudioStreamFormat(). |
| 946 | * |
| 947 | * \param devid an audio device to bind a stream to. |
| 948 | * \param streams an array of audio streams to bind. |
| 949 | * \param num_streams number streams listed in the `streams` array. |
| 950 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 951 | * information. |
| 952 | * |
| 953 | * \threadsafety It is safe to call this function from any thread. |
| 954 | * |
| 955 | * \since This function is available since SDL 3.2.0. |
| 956 | * |
| 957 | * \sa SDL_BindAudioStreams |
| 958 | * \sa SDL_UnbindAudioStream |
| 959 | * \sa SDL_GetAudioStreamDevice |
| 960 | */ |
| 961 | extern SDL_DECLSPEC bool SDLCALL SDL_BindAudioStreams(SDL_AudioDeviceID devid, SDL_AudioStream * const *streams, int num_streams); |
| 962 | |
| 963 | /** |
| 964 | * Bind a single audio stream to an audio device. |
| 965 | * |
| 966 | * This is a convenience function, equivalent to calling |
| 967 | * `SDL_BindAudioStreams(devid, &stream, 1)`. |
| 968 | * |
| 969 | * \param devid an audio device to bind a stream to. |
| 970 | * \param stream an audio stream to bind to a device. |
| 971 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 972 | * information. |
| 973 | * |
| 974 | * \threadsafety It is safe to call this function from any thread. |
| 975 | * |
| 976 | * \since This function is available since SDL 3.2.0. |
| 977 | * |
| 978 | * \sa SDL_BindAudioStreams |
| 979 | * \sa SDL_UnbindAudioStream |
| 980 | * \sa SDL_GetAudioStreamDevice |
| 981 | */ |
| 982 | extern SDL_DECLSPEC bool SDLCALL SDL_BindAudioStream(SDL_AudioDeviceID devid, SDL_AudioStream *stream); |
| 983 | |
| 984 | /** |
| 985 | * Unbind a list of audio streams from their audio devices. |
| 986 | * |
| 987 | * The streams being unbound do not all have to be on the same device. All |
| 988 | * streams on the same device will be unbound atomically (data will stop |
| 989 | * flowing through all unbound streams on the same device at the same time). |
| 990 | * |
| 991 | * Unbinding a stream that isn't bound to a device is a legal no-op. |
| 992 | * |
| 993 | * \param streams an array of audio streams to unbind. Can be NULL or contain |
| 994 | * NULL. |
| 995 | * \param num_streams number streams listed in the `streams` array. |
| 996 | * |
| 997 | * \threadsafety It is safe to call this function from any thread. |
| 998 | * |
| 999 | * \since This function is available since SDL 3.2.0. |
| 1000 | * |
| 1001 | * \sa SDL_BindAudioStreams |
| 1002 | */ |
| 1003 | extern SDL_DECLSPEC void SDLCALL SDL_UnbindAudioStreams(SDL_AudioStream * const *streams, int num_streams); |
| 1004 | |
| 1005 | /** |
| 1006 | * Unbind a single audio stream from its audio device. |
| 1007 | * |
| 1008 | * This is a convenience function, equivalent to calling |
| 1009 | * `SDL_UnbindAudioStreams(&stream, 1)`. |
| 1010 | * |
| 1011 | * \param stream an audio stream to unbind from a device. Can be NULL. |
| 1012 | * |
| 1013 | * \threadsafety It is safe to call this function from any thread. |
| 1014 | * |
| 1015 | * \since This function is available since SDL 3.2.0. |
| 1016 | * |
| 1017 | * \sa SDL_BindAudioStream |
| 1018 | */ |
| 1019 | extern SDL_DECLSPEC void SDLCALL SDL_UnbindAudioStream(SDL_AudioStream *stream); |
| 1020 | |
| 1021 | /** |
| 1022 | * Query an audio stream for its currently-bound device. |
| 1023 | * |
| 1024 | * This reports the audio device that an audio stream is currently bound to. |
| 1025 | * |
| 1026 | * If not bound, or invalid, this returns zero, which is not a valid device |
| 1027 | * ID. |
| 1028 | * |
| 1029 | * \param stream the audio stream to query. |
| 1030 | * \returns the bound audio device, or 0 if not bound or invalid. |
| 1031 | * |
| 1032 | * \threadsafety It is safe to call this function from any thread. |
| 1033 | * |
| 1034 | * \since This function is available since SDL 3.2.0. |
| 1035 | * |
| 1036 | * \sa SDL_BindAudioStream |
| 1037 | * \sa SDL_BindAudioStreams |
| 1038 | */ |
| 1039 | extern SDL_DECLSPEC SDL_AudioDeviceID SDLCALL SDL_GetAudioStreamDevice(SDL_AudioStream *stream); |
| 1040 | |
| 1041 | /** |
| 1042 | * Create a new audio stream. |
| 1043 | * |
| 1044 | * \param src_spec the format details of the input audio. |
| 1045 | * \param dst_spec the format details of the output audio. |
| 1046 | * \returns a new audio stream on success or NULL on failure; call |
| 1047 | * SDL_GetError() for more information. |
| 1048 | * |
| 1049 | * \threadsafety It is safe to call this function from any thread. |
| 1050 | * |
| 1051 | * \since This function is available since SDL 3.2.0. |
| 1052 | * |
| 1053 | * \sa SDL_PutAudioStreamData |
| 1054 | * \sa SDL_GetAudioStreamData |
| 1055 | * \sa SDL_GetAudioStreamAvailable |
| 1056 | * \sa SDL_FlushAudioStream |
| 1057 | * \sa SDL_ClearAudioStream |
| 1058 | * \sa SDL_SetAudioStreamFormat |
| 1059 | * \sa SDL_DestroyAudioStream |
| 1060 | */ |
| 1061 | extern SDL_DECLSPEC SDL_AudioStream * SDLCALL SDL_CreateAudioStream(const SDL_AudioSpec *src_spec, const SDL_AudioSpec *dst_spec); |
| 1062 | |
| 1063 | /** |
| 1064 | * Get the properties associated with an audio stream. |
| 1065 | * |
| 1066 | * \param stream the SDL_AudioStream to query. |
| 1067 | * \returns a valid property ID on success or 0 on failure; call |
| 1068 | * SDL_GetError() for more information. |
| 1069 | * |
| 1070 | * \threadsafety It is safe to call this function from any thread. |
| 1071 | * |
| 1072 | * \since This function is available since SDL 3.2.0. |
| 1073 | */ |
| 1074 | extern SDL_DECLSPEC SDL_PropertiesID SDLCALL SDL_GetAudioStreamProperties(SDL_AudioStream *stream); |
| 1075 | |
| 1076 | /** |
| 1077 | * Query the current format of an audio stream. |
| 1078 | * |
| 1079 | * \param stream the SDL_AudioStream to query. |
| 1080 | * \param src_spec where to store the input audio format; ignored if NULL. |
| 1081 | * \param dst_spec where to store the output audio format; ignored if NULL. |
| 1082 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1083 | * information. |
| 1084 | * |
| 1085 | * \threadsafety It is safe to call this function from any thread, as it holds |
| 1086 | * a stream-specific mutex while running. |
| 1087 | * |
| 1088 | * \since This function is available since SDL 3.2.0. |
| 1089 | * |
| 1090 | * \sa SDL_SetAudioStreamFormat |
| 1091 | */ |
| 1092 | extern SDL_DECLSPEC bool SDLCALL SDL_GetAudioStreamFormat(SDL_AudioStream *stream, SDL_AudioSpec *src_spec, SDL_AudioSpec *dst_spec); |
| 1093 | |
| 1094 | /** |
| 1095 | * Change the input and output formats of an audio stream. |
| 1096 | * |
| 1097 | * Future calls to and SDL_GetAudioStreamAvailable and SDL_GetAudioStreamData |
| 1098 | * will reflect the new format, and future calls to SDL_PutAudioStreamData |
| 1099 | * must provide data in the new input formats. |
| 1100 | * |
| 1101 | * Data that was previously queued in the stream will still be operated on in |
| 1102 | * the format that was current when it was added, which is to say you can put |
| 1103 | * the end of a sound file in one format to a stream, change formats for the |
| 1104 | * next sound file, and start putting that new data while the previous sound |
| 1105 | * file is still queued, and everything will still play back correctly. |
| 1106 | * |
| 1107 | * If a stream is bound to a device, then the format of the side of the stream |
| 1108 | * bound to a device cannot be changed (src_spec for recording devices, |
| 1109 | * dst_spec for playback devices). Attempts to make a change to this side will |
| 1110 | * be ignored, but this will not report an error. The other side's format can |
| 1111 | * be changed. |
| 1112 | * |
| 1113 | * \param stream the stream the format is being changed. |
| 1114 | * \param src_spec the new format of the audio input; if NULL, it is not |
| 1115 | * changed. |
| 1116 | * \param dst_spec the new format of the audio output; if NULL, it is not |
| 1117 | * changed. |
| 1118 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1119 | * information. |
| 1120 | * |
| 1121 | * \threadsafety It is safe to call this function from any thread, as it holds |
| 1122 | * a stream-specific mutex while running. |
| 1123 | * |
| 1124 | * \since This function is available since SDL 3.2.0. |
| 1125 | * |
| 1126 | * \sa SDL_GetAudioStreamFormat |
| 1127 | * \sa SDL_SetAudioStreamFrequencyRatio |
| 1128 | */ |
| 1129 | extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamFormat(SDL_AudioStream *stream, const SDL_AudioSpec *src_spec, const SDL_AudioSpec *dst_spec); |
| 1130 | |
| 1131 | /** |
| 1132 | * Get the frequency ratio of an audio stream. |
| 1133 | * |
| 1134 | * \param stream the SDL_AudioStream to query. |
| 1135 | * \returns the frequency ratio of the stream or 0.0 on failure; call |
| 1136 | * SDL_GetError() for more information. |
| 1137 | * |
| 1138 | * \threadsafety It is safe to call this function from any thread, as it holds |
| 1139 | * a stream-specific mutex while running. |
| 1140 | * |
| 1141 | * \since This function is available since SDL 3.2.0. |
| 1142 | * |
| 1143 | * \sa SDL_SetAudioStreamFrequencyRatio |
| 1144 | */ |
| 1145 | extern SDL_DECLSPEC float SDLCALL SDL_GetAudioStreamFrequencyRatio(SDL_AudioStream *stream); |
| 1146 | |
| 1147 | /** |
| 1148 | * Change the frequency ratio of an audio stream. |
| 1149 | * |
| 1150 | * The frequency ratio is used to adjust the rate at which input data is |
| 1151 | * consumed. Changing this effectively modifies the speed and pitch of the |
| 1152 | * audio. A value greater than 1.0 will play the audio faster, and at a higher |
| 1153 | * pitch. A value less than 1.0 will play the audio slower, and at a lower |
| 1154 | * pitch. |
| 1155 | * |
| 1156 | * This is applied during SDL_GetAudioStreamData, and can be continuously |
| 1157 | * changed to create various effects. |
| 1158 | * |
| 1159 | * \param stream the stream the frequency ratio is being changed. |
| 1160 | * \param ratio the frequency ratio. 1.0 is normal speed. Must be between 0.01 |
| 1161 | * and 100. |
| 1162 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1163 | * information. |
| 1164 | * |
| 1165 | * \threadsafety It is safe to call this function from any thread, as it holds |
| 1166 | * a stream-specific mutex while running. |
| 1167 | * |
| 1168 | * \since This function is available since SDL 3.2.0. |
| 1169 | * |
| 1170 | * \sa SDL_GetAudioStreamFrequencyRatio |
| 1171 | * \sa SDL_SetAudioStreamFormat |
| 1172 | */ |
| 1173 | extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamFrequencyRatio(SDL_AudioStream *stream, float ratio); |
| 1174 | |
| 1175 | /** |
| 1176 | * Get the gain of an audio stream. |
| 1177 | * |
| 1178 | * The gain of a stream is its volume; a larger gain means a louder output, |
| 1179 | * with a gain of zero being silence. |
| 1180 | * |
| 1181 | * Audio streams default to a gain of 1.0f (no change in output). |
| 1182 | * |
| 1183 | * \param stream the SDL_AudioStream to query. |
| 1184 | * \returns the gain of the stream or -1.0f on failure; call SDL_GetError() |
| 1185 | * for more information. |
| 1186 | * |
| 1187 | * \threadsafety It is safe to call this function from any thread, as it holds |
| 1188 | * a stream-specific mutex while running. |
| 1189 | * |
| 1190 | * \since This function is available since SDL 3.2.0. |
| 1191 | * |
| 1192 | * \sa SDL_SetAudioStreamGain |
| 1193 | */ |
| 1194 | extern SDL_DECLSPEC float SDLCALL SDL_GetAudioStreamGain(SDL_AudioStream *stream); |
| 1195 | |
| 1196 | /** |
| 1197 | * Change the gain of an audio stream. |
| 1198 | * |
| 1199 | * The gain of a stream is its volume; a larger gain means a louder output, |
| 1200 | * with a gain of zero being silence. |
| 1201 | * |
| 1202 | * Audio streams default to a gain of 1.0f (no change in output). |
| 1203 | * |
| 1204 | * This is applied during SDL_GetAudioStreamData, and can be continuously |
| 1205 | * changed to create various effects. |
| 1206 | * |
| 1207 | * \param stream the stream on which the gain is being changed. |
| 1208 | * \param gain the gain. 1.0f is no change, 0.0f is silence. |
| 1209 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1210 | * information. |
| 1211 | * |
| 1212 | * \threadsafety It is safe to call this function from any thread, as it holds |
| 1213 | * a stream-specific mutex while running. |
| 1214 | * |
| 1215 | * \since This function is available since SDL 3.2.0. |
| 1216 | * |
| 1217 | * \sa SDL_GetAudioStreamGain |
| 1218 | */ |
| 1219 | extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamGain(SDL_AudioStream *stream, float gain); |
| 1220 | |
| 1221 | /** |
| 1222 | * Get the current input channel map of an audio stream. |
| 1223 | * |
| 1224 | * Channel maps are optional; most things do not need them, instead passing |
| 1225 | * data in the [order that SDL expects](CategoryAudio#channel-layouts). |
| 1226 | * |
| 1227 | * Audio streams default to no remapping applied. This is represented by |
| 1228 | * returning NULL, and does not signify an error. |
| 1229 | * |
| 1230 | * \param stream the SDL_AudioStream to query. |
| 1231 | * \param count On output, set to number of channels in the map. Can be NULL. |
| 1232 | * \returns an array of the current channel mapping, with as many elements as |
| 1233 | * the current output spec's channels, or NULL if default. This |
| 1234 | * should be freed with SDL_free() when it is no longer needed. |
| 1235 | * |
| 1236 | * \threadsafety It is safe to call this function from any thread, as it holds |
| 1237 | * a stream-specific mutex while running. |
| 1238 | * |
| 1239 | * \since This function is available since SDL 3.2.0. |
| 1240 | * |
| 1241 | * \sa SDL_SetAudioStreamInputChannelMap |
| 1242 | */ |
| 1243 | extern SDL_DECLSPEC int * SDLCALL SDL_GetAudioStreamInputChannelMap(SDL_AudioStream *stream, int *count); |
| 1244 | |
| 1245 | /** |
| 1246 | * Get the current output channel map of an audio stream. |
| 1247 | * |
| 1248 | * Channel maps are optional; most things do not need them, instead passing |
| 1249 | * data in the [order that SDL expects](CategoryAudio#channel-layouts). |
| 1250 | * |
| 1251 | * Audio streams default to no remapping applied. This is represented by |
| 1252 | * returning NULL, and does not signify an error. |
| 1253 | * |
| 1254 | * \param stream the SDL_AudioStream to query. |
| 1255 | * \param count On output, set to number of channels in the map. Can be NULL. |
| 1256 | * \returns an array of the current channel mapping, with as many elements as |
| 1257 | * the current output spec's channels, or NULL if default. This |
| 1258 | * should be freed with SDL_free() when it is no longer needed. |
| 1259 | * |
| 1260 | * \threadsafety It is safe to call this function from any thread, as it holds |
| 1261 | * a stream-specific mutex while running. |
| 1262 | * |
| 1263 | * \since This function is available since SDL 3.2.0. |
| 1264 | * |
| 1265 | * \sa SDL_SetAudioStreamInputChannelMap |
| 1266 | */ |
| 1267 | extern SDL_DECLSPEC int * SDLCALL SDL_GetAudioStreamOutputChannelMap(SDL_AudioStream *stream, int *count); |
| 1268 | |
| 1269 | /** |
| 1270 | * Set the current input channel map of an audio stream. |
| 1271 | * |
| 1272 | * Channel maps are optional; most things do not need them, instead passing |
| 1273 | * data in the [order that SDL expects](CategoryAudio#channel-layouts). |
| 1274 | * |
| 1275 | * The input channel map reorders data that is added to a stream via |
| 1276 | * SDL_PutAudioStreamData. Future calls to SDL_PutAudioStreamData must provide |
| 1277 | * data in the new channel order. |
| 1278 | * |
| 1279 | * Each item in the array represents an input channel, and its value is the |
| 1280 | * channel that it should be remapped to. To reverse a stereo signal's left |
| 1281 | * and right values, you'd have an array of `{ 1, 0 }`. It is legal to remap |
| 1282 | * multiple channels to the same thing, so `{ 1, 1 }` would duplicate the |
| 1283 | * right channel to both channels of a stereo signal. An element in the |
| 1284 | * channel map set to -1 instead of a valid channel will mute that channel, |
| 1285 | * setting it to a silence value. |
| 1286 | * |
| 1287 | * You cannot change the number of channels through a channel map, just |
| 1288 | * reorder/mute them. |
| 1289 | * |
| 1290 | * Data that was previously queued in the stream will still be operated on in |
| 1291 | * the order that was current when it was added, which is to say you can put |
| 1292 | * the end of a sound file in one order to a stream, change orders for the |
| 1293 | * next sound file, and start putting that new data while the previous sound |
| 1294 | * file is still queued, and everything will still play back correctly. |
| 1295 | * |
| 1296 | * Audio streams default to no remapping applied. Passing a NULL channel map |
| 1297 | * is legal, and turns off remapping. |
| 1298 | * |
| 1299 | * SDL will copy the channel map; the caller does not have to save this array |
| 1300 | * after this call. |
| 1301 | * |
| 1302 | * If `count` is not equal to the current number of channels in the audio |
| 1303 | * stream's format, this will fail. This is a safety measure to make sure a |
| 1304 | * race condition hasn't changed the format while this call is setting the |
| 1305 | * channel map. |
| 1306 | * |
| 1307 | * Unlike attempting to change the stream's format, the input channel map on a |
| 1308 | * stream bound to a recording device is permitted to change at any time; any |
| 1309 | * data added to the stream from the device after this call will have the new |
| 1310 | * mapping, but previously-added data will still have the prior mapping. |
| 1311 | * |
| 1312 | * \param stream the SDL_AudioStream to change. |
| 1313 | * \param chmap the new channel map, NULL to reset to default. |
| 1314 | * \param count The number of channels in the map. |
| 1315 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1316 | * information. |
| 1317 | * |
| 1318 | * \threadsafety It is safe to call this function from any thread, as it holds |
| 1319 | * a stream-specific mutex while running. Don't change the |
| 1320 | * stream's format to have a different number of channels from a |
| 1321 | * a different thread at the same time, though! |
| 1322 | * |
| 1323 | * \since This function is available since SDL 3.2.0. |
| 1324 | * |
| 1325 | * \sa SDL_SetAudioStreamInputChannelMap |
| 1326 | */ |
| 1327 | extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamInputChannelMap(SDL_AudioStream *stream, const int *chmap, int count); |
| 1328 | |
| 1329 | /** |
| 1330 | * Set the current output channel map of an audio stream. |
| 1331 | * |
| 1332 | * Channel maps are optional; most things do not need them, instead passing |
| 1333 | * data in the [order that SDL expects](CategoryAudio#channel-layouts). |
| 1334 | * |
| 1335 | * The output channel map reorders data that leaving a stream via |
| 1336 | * SDL_GetAudioStreamData. |
| 1337 | * |
| 1338 | * Each item in the array represents an input channel, and its value is the |
| 1339 | * channel that it should be remapped to. To reverse a stereo signal's left |
| 1340 | * and right values, you'd have an array of `{ 1, 0 }`. It is legal to remap |
| 1341 | * multiple channels to the same thing, so `{ 1, 1 }` would duplicate the |
| 1342 | * right channel to both channels of a stereo signal. An element in the |
| 1343 | * channel map set to -1 instead of a valid channel will mute that channel, |
| 1344 | * setting it to a silence value. |
| 1345 | * |
| 1346 | * You cannot change the number of channels through a channel map, just |
| 1347 | * reorder/mute them. |
| 1348 | * |
| 1349 | * The output channel map can be changed at any time, as output remapping is |
| 1350 | * applied during SDL_GetAudioStreamData. |
| 1351 | * |
| 1352 | * Audio streams default to no remapping applied. Passing a NULL channel map |
| 1353 | * is legal, and turns off remapping. |
| 1354 | * |
| 1355 | * SDL will copy the channel map; the caller does not have to save this array |
| 1356 | * after this call. |
| 1357 | * |
| 1358 | * If `count` is not equal to the current number of channels in the audio |
| 1359 | * stream's format, this will fail. This is a safety measure to make sure a |
| 1360 | * race condition hasn't changed the format while this call is setting the |
| 1361 | * channel map. |
| 1362 | * |
| 1363 | * Unlike attempting to change the stream's format, the output channel map on |
| 1364 | * a stream bound to a recording device is permitted to change at any time; |
| 1365 | * any data added to the stream after this call will have the new mapping, but |
| 1366 | * previously-added data will still have the prior mapping. When the channel |
| 1367 | * map doesn't match the hardware's channel layout, SDL will convert the data |
| 1368 | * before feeding it to the device for playback. |
| 1369 | * |
| 1370 | * \param stream the SDL_AudioStream to change. |
| 1371 | * \param chmap the new channel map, NULL to reset to default. |
| 1372 | * \param count The number of channels in the map. |
| 1373 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1374 | * information. |
| 1375 | * |
| 1376 | * \threadsafety It is safe to call this function from any thread, as it holds |
| 1377 | * a stream-specific mutex while running. Don't change the |
| 1378 | * stream's format to have a different number of channels from a |
| 1379 | * a different thread at the same time, though! |
| 1380 | * |
| 1381 | * \since This function is available since SDL 3.2.0. |
| 1382 | * |
| 1383 | * \sa SDL_SetAudioStreamInputChannelMap |
| 1384 | */ |
| 1385 | extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamOutputChannelMap(SDL_AudioStream *stream, const int *chmap, int count); |
| 1386 | |
| 1387 | /** |
| 1388 | * Add data to the stream. |
| 1389 | * |
| 1390 | * This data must match the format/channels/samplerate specified in the latest |
| 1391 | * call to SDL_SetAudioStreamFormat, or the format specified when creating the |
| 1392 | * stream if it hasn't been changed. |
| 1393 | * |
| 1394 | * Note that this call simply copies the unconverted data for later. This is |
| 1395 | * different than SDL2, where data was converted during the Put call and the |
| 1396 | * Get call would just dequeue the previously-converted data. |
| 1397 | * |
| 1398 | * \param stream the stream the audio data is being added to. |
| 1399 | * \param buf a pointer to the audio data to add. |
| 1400 | * \param len the number of bytes to write to the stream. |
| 1401 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1402 | * information. |
| 1403 | * |
| 1404 | * \threadsafety It is safe to call this function from any thread, but if the |
| 1405 | * stream has a callback set, the caller might need to manage |
| 1406 | * extra locking. |
| 1407 | * |
| 1408 | * \since This function is available since SDL 3.2.0. |
| 1409 | * |
| 1410 | * \sa SDL_ClearAudioStream |
| 1411 | * \sa SDL_FlushAudioStream |
| 1412 | * \sa SDL_GetAudioStreamData |
| 1413 | * \sa SDL_GetAudioStreamQueued |
| 1414 | */ |
| 1415 | extern SDL_DECLSPEC bool SDLCALL SDL_PutAudioStreamData(SDL_AudioStream *stream, const void *buf, int len); |
| 1416 | |
| 1417 | /** |
| 1418 | * Get converted/resampled data from the stream. |
| 1419 | * |
| 1420 | * The input/output data format/channels/samplerate is specified when creating |
| 1421 | * the stream, and can be changed after creation by calling |
| 1422 | * SDL_SetAudioStreamFormat. |
| 1423 | * |
| 1424 | * Note that any conversion and resampling necessary is done during this call, |
| 1425 | * and SDL_PutAudioStreamData simply queues unconverted data for later. This |
| 1426 | * is different than SDL2, where that work was done while inputting new data |
| 1427 | * to the stream and requesting the output just copied the converted data. |
| 1428 | * |
| 1429 | * \param stream the stream the audio is being requested from. |
| 1430 | * \param buf a buffer to fill with audio data. |
| 1431 | * \param len the maximum number of bytes to fill. |
| 1432 | * \returns the number of bytes read from the stream or -1 on failure; call |
| 1433 | * SDL_GetError() for more information. |
| 1434 | * |
| 1435 | * \threadsafety It is safe to call this function from any thread, but if the |
| 1436 | * stream has a callback set, the caller might need to manage |
| 1437 | * extra locking. |
| 1438 | * |
| 1439 | * \since This function is available since SDL 3.2.0. |
| 1440 | * |
| 1441 | * \sa SDL_ClearAudioStream |
| 1442 | * \sa SDL_GetAudioStreamAvailable |
| 1443 | * \sa SDL_PutAudioStreamData |
| 1444 | */ |
| 1445 | extern SDL_DECLSPEC int SDLCALL SDL_GetAudioStreamData(SDL_AudioStream *stream, void *buf, int len); |
| 1446 | |
| 1447 | /** |
| 1448 | * Get the number of converted/resampled bytes available. |
| 1449 | * |
| 1450 | * The stream may be buffering data behind the scenes until it has enough to |
| 1451 | * resample correctly, so this number might be lower than what you expect, or |
| 1452 | * even be zero. Add more data or flush the stream if you need the data now. |
| 1453 | * |
| 1454 | * If the stream has so much data that it would overflow an int, the return |
| 1455 | * value is clamped to a maximum value, but no queued data is lost; if there |
| 1456 | * are gigabytes of data queued, the app might need to read some of it with |
| 1457 | * SDL_GetAudioStreamData before this function's return value is no longer |
| 1458 | * clamped. |
| 1459 | * |
| 1460 | * \param stream the audio stream to query. |
| 1461 | * \returns the number of converted/resampled bytes available or -1 on |
| 1462 | * failure; call SDL_GetError() for more information. |
| 1463 | * |
| 1464 | * \threadsafety It is safe to call this function from any thread. |
| 1465 | * |
| 1466 | * \since This function is available since SDL 3.2.0. |
| 1467 | * |
| 1468 | * \sa SDL_GetAudioStreamData |
| 1469 | * \sa SDL_PutAudioStreamData |
| 1470 | */ |
| 1471 | extern SDL_DECLSPEC int SDLCALL SDL_GetAudioStreamAvailable(SDL_AudioStream *stream); |
| 1472 | |
| 1473 | |
| 1474 | /** |
| 1475 | * Get the number of bytes currently queued. |
| 1476 | * |
| 1477 | * This is the number of bytes put into a stream as input, not the number that |
| 1478 | * can be retrieved as output. Because of several details, it's not possible |
| 1479 | * to calculate one number directly from the other. If you need to know how |
| 1480 | * much usable data can be retrieved right now, you should use |
| 1481 | * SDL_GetAudioStreamAvailable() and not this function. |
| 1482 | * |
| 1483 | * Note that audio streams can change their input format at any time, even if |
| 1484 | * there is still data queued in a different format, so the returned byte |
| 1485 | * count will not necessarily match the number of _sample frames_ available. |
| 1486 | * Users of this API should be aware of format changes they make when feeding |
| 1487 | * a stream and plan accordingly. |
| 1488 | * |
| 1489 | * Queued data is not converted until it is consumed by |
| 1490 | * SDL_GetAudioStreamData, so this value should be representative of the exact |
| 1491 | * data that was put into the stream. |
| 1492 | * |
| 1493 | * If the stream has so much data that it would overflow an int, the return |
| 1494 | * value is clamped to a maximum value, but no queued data is lost; if there |
| 1495 | * are gigabytes of data queued, the app might need to read some of it with |
| 1496 | * SDL_GetAudioStreamData before this function's return value is no longer |
| 1497 | * clamped. |
| 1498 | * |
| 1499 | * \param stream the audio stream to query. |
| 1500 | * \returns the number of bytes queued or -1 on failure; call SDL_GetError() |
| 1501 | * for more information. |
| 1502 | * |
| 1503 | * \threadsafety It is safe to call this function from any thread. |
| 1504 | * |
| 1505 | * \since This function is available since SDL 3.2.0. |
| 1506 | * |
| 1507 | * \sa SDL_PutAudioStreamData |
| 1508 | * \sa SDL_ClearAudioStream |
| 1509 | */ |
| 1510 | extern SDL_DECLSPEC int SDLCALL SDL_GetAudioStreamQueued(SDL_AudioStream *stream); |
| 1511 | |
| 1512 | |
| 1513 | /** |
| 1514 | * Tell the stream that you're done sending data, and anything being buffered |
| 1515 | * should be converted/resampled and made available immediately. |
| 1516 | * |
| 1517 | * It is legal to add more data to a stream after flushing, but there may be |
| 1518 | * audio gaps in the output. Generally this is intended to signal the end of |
| 1519 | * input, so the complete output becomes available. |
| 1520 | * |
| 1521 | * \param stream the audio stream to flush. |
| 1522 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1523 | * information. |
| 1524 | * |
| 1525 | * \threadsafety It is safe to call this function from any thread. |
| 1526 | * |
| 1527 | * \since This function is available since SDL 3.2.0. |
| 1528 | * |
| 1529 | * \sa SDL_PutAudioStreamData |
| 1530 | */ |
| 1531 | extern SDL_DECLSPEC bool SDLCALL SDL_FlushAudioStream(SDL_AudioStream *stream); |
| 1532 | |
| 1533 | /** |
| 1534 | * Clear any pending data in the stream. |
| 1535 | * |
| 1536 | * This drops any queued data, so there will be nothing to read from the |
| 1537 | * stream until more is added. |
| 1538 | * |
| 1539 | * \param stream the audio stream to clear. |
| 1540 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1541 | * information. |
| 1542 | * |
| 1543 | * \threadsafety It is safe to call this function from any thread. |
| 1544 | * |
| 1545 | * \since This function is available since SDL 3.2.0. |
| 1546 | * |
| 1547 | * \sa SDL_GetAudioStreamAvailable |
| 1548 | * \sa SDL_GetAudioStreamData |
| 1549 | * \sa SDL_GetAudioStreamQueued |
| 1550 | * \sa SDL_PutAudioStreamData |
| 1551 | */ |
| 1552 | extern SDL_DECLSPEC bool SDLCALL SDL_ClearAudioStream(SDL_AudioStream *stream); |
| 1553 | |
| 1554 | /** |
| 1555 | * Use this function to pause audio playback on the audio device associated |
| 1556 | * with an audio stream. |
| 1557 | * |
| 1558 | * This function pauses audio processing for a given device. Any bound audio |
| 1559 | * streams will not progress, and no audio will be generated. Pausing one |
| 1560 | * device does not prevent other unpaused devices from running. |
| 1561 | * |
| 1562 | * Pausing a device can be useful to halt all audio without unbinding all the |
| 1563 | * audio streams. This might be useful while a game is paused, or a level is |
| 1564 | * loading, etc. |
| 1565 | * |
| 1566 | * \param stream the audio stream associated with the audio device to pause. |
| 1567 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1568 | * information. |
| 1569 | * |
| 1570 | * \threadsafety It is safe to call this function from any thread. |
| 1571 | * |
| 1572 | * \since This function is available since SDL 3.2.0. |
| 1573 | * |
| 1574 | * \sa SDL_ResumeAudioStreamDevice |
| 1575 | */ |
| 1576 | extern SDL_DECLSPEC bool SDLCALL SDL_PauseAudioStreamDevice(SDL_AudioStream *stream); |
| 1577 | |
| 1578 | /** |
| 1579 | * Use this function to unpause audio playback on the audio device associated |
| 1580 | * with an audio stream. |
| 1581 | * |
| 1582 | * This function unpauses audio processing for a given device that has |
| 1583 | * previously been paused. Once unpaused, any bound audio streams will begin |
| 1584 | * to progress again, and audio can be generated. |
| 1585 | * |
| 1586 | * Remember, SDL_OpenAudioDeviceStream opens device in a paused state, so this |
| 1587 | * function call is required for audio playback to begin on such device. |
| 1588 | * |
| 1589 | * \param stream the audio stream associated with the audio device to resume. |
| 1590 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1591 | * information. |
| 1592 | * |
| 1593 | * \threadsafety It is safe to call this function from any thread. |
| 1594 | * |
| 1595 | * \since This function is available since SDL 3.2.0. |
| 1596 | * |
| 1597 | * \sa SDL_PauseAudioStreamDevice |
| 1598 | */ |
| 1599 | extern SDL_DECLSPEC bool SDLCALL SDL_ResumeAudioStreamDevice(SDL_AudioStream *stream); |
| 1600 | |
| 1601 | /** |
| 1602 | * Use this function to query if an audio device associated with a stream is |
| 1603 | * paused. |
| 1604 | * |
| 1605 | * Unlike in SDL2, audio devices start in an _unpaused_ state, since an app |
| 1606 | * has to bind a stream before any audio will flow. |
| 1607 | * |
| 1608 | * \param stream the audio stream associated with the audio device to query. |
| 1609 | * \returns true if device is valid and paused, false otherwise. |
| 1610 | * |
| 1611 | * \threadsafety It is safe to call this function from any thread. |
| 1612 | * |
| 1613 | * \since This function is available since SDL 3.2.0. |
| 1614 | * |
| 1615 | * \sa SDL_PauseAudioStreamDevice |
| 1616 | * \sa SDL_ResumeAudioStreamDevice |
| 1617 | */ |
| 1618 | extern SDL_DECLSPEC bool SDLCALL SDL_AudioStreamDevicePaused(SDL_AudioStream *stream); |
| 1619 | |
| 1620 | |
| 1621 | /** |
| 1622 | * Lock an audio stream for serialized access. |
| 1623 | * |
| 1624 | * Each SDL_AudioStream has an internal mutex it uses to protect its data |
| 1625 | * structures from threading conflicts. This function allows an app to lock |
| 1626 | * that mutex, which could be useful if registering callbacks on this stream. |
| 1627 | * |
| 1628 | * One does not need to lock a stream to use in it most cases, as the stream |
| 1629 | * manages this lock internally. However, this lock is held during callbacks, |
| 1630 | * which may run from arbitrary threads at any time, so if an app needs to |
| 1631 | * protect shared data during those callbacks, locking the stream guarantees |
| 1632 | * that the callback is not running while the lock is held. |
| 1633 | * |
| 1634 | * As this is just a wrapper over SDL_LockMutex for an internal lock; it has |
| 1635 | * all the same attributes (recursive locks are allowed, etc). |
| 1636 | * |
| 1637 | * \param stream the audio stream to lock. |
| 1638 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1639 | * information. |
| 1640 | * |
| 1641 | * \threadsafety It is safe to call this function from any thread. |
| 1642 | * |
| 1643 | * \since This function is available since SDL 3.2.0. |
| 1644 | * |
| 1645 | * \sa SDL_UnlockAudioStream |
| 1646 | */ |
| 1647 | extern SDL_DECLSPEC bool SDLCALL SDL_LockAudioStream(SDL_AudioStream *stream); |
| 1648 | |
| 1649 | |
| 1650 | /** |
| 1651 | * Unlock an audio stream for serialized access. |
| 1652 | * |
| 1653 | * This unlocks an audio stream after a call to SDL_LockAudioStream. |
| 1654 | * |
| 1655 | * \param stream the audio stream to unlock. |
| 1656 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1657 | * information. |
| 1658 | * |
| 1659 | * \threadsafety You should only call this from the same thread that |
| 1660 | * previously called SDL_LockAudioStream. |
| 1661 | * |
| 1662 | * \since This function is available since SDL 3.2.0. |
| 1663 | * |
| 1664 | * \sa SDL_LockAudioStream |
| 1665 | */ |
| 1666 | extern SDL_DECLSPEC bool SDLCALL SDL_UnlockAudioStream(SDL_AudioStream *stream); |
| 1667 | |
| 1668 | /** |
| 1669 | * A callback that fires when data passes through an SDL_AudioStream. |
| 1670 | * |
| 1671 | * Apps can (optionally) register a callback with an audio stream that is |
| 1672 | * called when data is added with SDL_PutAudioStreamData, or requested with |
| 1673 | * SDL_GetAudioStreamData. |
| 1674 | * |
| 1675 | * Two values are offered here: one is the amount of additional data needed to |
| 1676 | * satisfy the immediate request (which might be zero if the stream already |
| 1677 | * has enough data queued) and the other is the total amount being requested. |
| 1678 | * In a Get call triggering a Put callback, these values can be different. In |
| 1679 | * a Put call triggering a Get callback, these values are always the same. |
| 1680 | * |
| 1681 | * Byte counts might be slightly overestimated due to buffering or resampling, |
| 1682 | * and may change from call to call. |
| 1683 | * |
| 1684 | * This callback is not required to do anything. Generally this is useful for |
| 1685 | * adding/reading data on demand, and the app will often put/get data as |
| 1686 | * appropriate, but the system goes on with the data currently available to it |
| 1687 | * if this callback does nothing. |
| 1688 | * |
| 1689 | * \param stream the SDL audio stream associated with this callback. |
| 1690 | * \param additional_amount the amount of data, in bytes, that is needed right |
| 1691 | * now. |
| 1692 | * \param total_amount the total amount of data requested, in bytes, that is |
| 1693 | * requested or available. |
| 1694 | * \param userdata an opaque pointer provided by the app for their personal |
| 1695 | * use. |
| 1696 | * |
| 1697 | * \threadsafety This callbacks may run from any thread, so if you need to |
| 1698 | * protect shared data, you should use SDL_LockAudioStream to |
| 1699 | * serialize access; this lock will be held before your callback |
| 1700 | * is called, so your callback does not need to manage the lock |
| 1701 | * explicitly. |
| 1702 | * |
| 1703 | * \since This datatype is available since SDL 3.2.0. |
| 1704 | * |
| 1705 | * \sa SDL_SetAudioStreamGetCallback |
| 1706 | * \sa SDL_SetAudioStreamPutCallback |
| 1707 | */ |
| 1708 | typedef void (SDLCALL *SDL_AudioStreamCallback)(void *userdata, SDL_AudioStream *stream, int additional_amount, int total_amount); |
| 1709 | |
| 1710 | /** |
| 1711 | * Set a callback that runs when data is requested from an audio stream. |
| 1712 | * |
| 1713 | * This callback is called _before_ data is obtained from the stream, giving |
| 1714 | * the callback the chance to add more on-demand. |
| 1715 | * |
| 1716 | * The callback can (optionally) call SDL_PutAudioStreamData() to add more |
| 1717 | * audio to the stream during this call; if needed, the request that triggered |
| 1718 | * this callback will obtain the new data immediately. |
| 1719 | * |
| 1720 | * The callback's `approx_request` argument is roughly how many bytes of |
| 1721 | * _unconverted_ data (in the stream's input format) is needed by the caller, |
| 1722 | * although this may overestimate a little for safety. This takes into account |
| 1723 | * how much is already in the stream and only asks for any extra necessary to |
| 1724 | * resolve the request, which means the callback may be asked for zero bytes, |
| 1725 | * and a different amount on each call. |
| 1726 | * |
| 1727 | * The callback is not required to supply exact amounts; it is allowed to |
| 1728 | * supply too much or too little or none at all. The caller will get what's |
| 1729 | * available, up to the amount they requested, regardless of this callback's |
| 1730 | * outcome. |
| 1731 | * |
| 1732 | * Clearing or flushing an audio stream does not call this callback. |
| 1733 | * |
| 1734 | * This function obtains the stream's lock, which means any existing callback |
| 1735 | * (get or put) in progress will finish running before setting the new |
| 1736 | * callback. |
| 1737 | * |
| 1738 | * Setting a NULL function turns off the callback. |
| 1739 | * |
| 1740 | * \param stream the audio stream to set the new callback on. |
| 1741 | * \param callback the new callback function to call when data is requested |
| 1742 | * from the stream. |
| 1743 | * \param userdata an opaque pointer provided to the callback for its own |
| 1744 | * personal use. |
| 1745 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1746 | * information. This only fails if `stream` is NULL. |
| 1747 | * |
| 1748 | * \threadsafety It is safe to call this function from any thread. |
| 1749 | * |
| 1750 | * \since This function is available since SDL 3.2.0. |
| 1751 | * |
| 1752 | * \sa SDL_SetAudioStreamPutCallback |
| 1753 | */ |
| 1754 | extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamGetCallback(SDL_AudioStream *stream, SDL_AudioStreamCallback callback, void *userdata); |
| 1755 | |
| 1756 | /** |
| 1757 | * Set a callback that runs when data is added to an audio stream. |
| 1758 | * |
| 1759 | * This callback is called _after_ the data is added to the stream, giving the |
| 1760 | * callback the chance to obtain it immediately. |
| 1761 | * |
| 1762 | * The callback can (optionally) call SDL_GetAudioStreamData() to obtain audio |
| 1763 | * from the stream during this call. |
| 1764 | * |
| 1765 | * The callback's `approx_request` argument is how many bytes of _converted_ |
| 1766 | * data (in the stream's output format) was provided by the caller, although |
| 1767 | * this may underestimate a little for safety. This value might be less than |
| 1768 | * what is currently available in the stream, if data was already there, and |
| 1769 | * might be less than the caller provided if the stream needs to keep a buffer |
| 1770 | * to aid in resampling. Which means the callback may be provided with zero |
| 1771 | * bytes, and a different amount on each call. |
| 1772 | * |
| 1773 | * The callback may call SDL_GetAudioStreamAvailable to see the total amount |
| 1774 | * currently available to read from the stream, instead of the total provided |
| 1775 | * by the current call. |
| 1776 | * |
| 1777 | * The callback is not required to obtain all data. It is allowed to read less |
| 1778 | * or none at all. Anything not read now simply remains in the stream for |
| 1779 | * later access. |
| 1780 | * |
| 1781 | * Clearing or flushing an audio stream does not call this callback. |
| 1782 | * |
| 1783 | * This function obtains the stream's lock, which means any existing callback |
| 1784 | * (get or put) in progress will finish running before setting the new |
| 1785 | * callback. |
| 1786 | * |
| 1787 | * Setting a NULL function turns off the callback. |
| 1788 | * |
| 1789 | * \param stream the audio stream to set the new callback on. |
| 1790 | * \param callback the new callback function to call when data is added to the |
| 1791 | * stream. |
| 1792 | * \param userdata an opaque pointer provided to the callback for its own |
| 1793 | * personal use. |
| 1794 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1795 | * information. This only fails if `stream` is NULL. |
| 1796 | * |
| 1797 | * \threadsafety It is safe to call this function from any thread. |
| 1798 | * |
| 1799 | * \since This function is available since SDL 3.2.0. |
| 1800 | * |
| 1801 | * \sa SDL_SetAudioStreamGetCallback |
| 1802 | */ |
| 1803 | extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamPutCallback(SDL_AudioStream *stream, SDL_AudioStreamCallback callback, void *userdata); |
| 1804 | |
| 1805 | |
| 1806 | /** |
| 1807 | * Free an audio stream. |
| 1808 | * |
| 1809 | * This will release all allocated data, including any audio that is still |
| 1810 | * queued. You do not need to manually clear the stream first. |
| 1811 | * |
| 1812 | * If this stream was bound to an audio device, it is unbound during this |
| 1813 | * call. If this stream was created with SDL_OpenAudioDeviceStream, the audio |
| 1814 | * device that was opened alongside this stream's creation will be closed, |
| 1815 | * too. |
| 1816 | * |
| 1817 | * \param stream the audio stream to destroy. |
| 1818 | * |
| 1819 | * \threadsafety It is safe to call this function from any thread. |
| 1820 | * |
| 1821 | * \since This function is available since SDL 3.2.0. |
| 1822 | * |
| 1823 | * \sa SDL_CreateAudioStream |
| 1824 | */ |
| 1825 | extern SDL_DECLSPEC void SDLCALL SDL_DestroyAudioStream(SDL_AudioStream *stream); |
| 1826 | |
| 1827 | |
| 1828 | /** |
| 1829 | * Convenience function for straightforward audio init for the common case. |
| 1830 | * |
| 1831 | * If all your app intends to do is provide a single source of PCM audio, this |
| 1832 | * function allows you to do all your audio setup in a single call. |
| 1833 | * |
| 1834 | * This is also intended to be a clean means to migrate apps from SDL2. |
| 1835 | * |
| 1836 | * This function will open an audio device, create a stream and bind it. |
| 1837 | * Unlike other methods of setup, the audio device will be closed when this |
| 1838 | * stream is destroyed, so the app can treat the returned SDL_AudioStream as |
| 1839 | * the only object needed to manage audio playback. |
| 1840 | * |
| 1841 | * Also unlike other functions, the audio device begins paused. This is to map |
| 1842 | * more closely to SDL2-style behavior, since there is no extra step here to |
| 1843 | * bind a stream to begin audio flowing. The audio device should be resumed |
| 1844 | * with `SDL_ResumeAudioStreamDevice(stream);` |
| 1845 | * |
| 1846 | * This function works with both playback and recording devices. |
| 1847 | * |
| 1848 | * The `spec` parameter represents the app's side of the audio stream. That |
| 1849 | * is, for recording audio, this will be the output format, and for playing |
| 1850 | * audio, this will be the input format. If spec is NULL, the system will |
| 1851 | * choose the format, and the app can use SDL_GetAudioStreamFormat() to obtain |
| 1852 | * this information later. |
| 1853 | * |
| 1854 | * If you don't care about opening a specific audio device, you can (and |
| 1855 | * probably _should_), use SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK for playback and |
| 1856 | * SDL_AUDIO_DEVICE_DEFAULT_RECORDING for recording. |
| 1857 | * |
| 1858 | * One can optionally provide a callback function; if NULL, the app is |
| 1859 | * expected to queue audio data for playback (or unqueue audio data if |
| 1860 | * capturing). Otherwise, the callback will begin to fire once the device is |
| 1861 | * unpaused. |
| 1862 | * |
| 1863 | * Destroying the returned stream with SDL_DestroyAudioStream will also close |
| 1864 | * the audio device associated with this stream. |
| 1865 | * |
| 1866 | * \param devid an audio device to open, or SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK |
| 1867 | * or SDL_AUDIO_DEVICE_DEFAULT_RECORDING. |
| 1868 | * \param spec the audio stream's data format. Can be NULL. |
| 1869 | * \param callback a callback where the app will provide new data for |
| 1870 | * playback, or receive new data for recording. Can be NULL, |
| 1871 | * in which case the app will need to call |
| 1872 | * SDL_PutAudioStreamData or SDL_GetAudioStreamData as |
| 1873 | * necessary. |
| 1874 | * \param userdata app-controlled pointer passed to callback. Can be NULL. |
| 1875 | * Ignored if callback is NULL. |
| 1876 | * \returns an audio stream on success, ready to use, or NULL on failure; call |
| 1877 | * SDL_GetError() for more information. When done with this stream, |
| 1878 | * call SDL_DestroyAudioStream to free resources and close the |
| 1879 | * device. |
| 1880 | * |
| 1881 | * \threadsafety It is safe to call this function from any thread. |
| 1882 | * |
| 1883 | * \since This function is available since SDL 3.2.0. |
| 1884 | * |
| 1885 | * \sa SDL_GetAudioStreamDevice |
| 1886 | * \sa SDL_ResumeAudioStreamDevice |
| 1887 | */ |
| 1888 | extern SDL_DECLSPEC SDL_AudioStream * SDLCALL SDL_OpenAudioDeviceStream(SDL_AudioDeviceID devid, const SDL_AudioSpec *spec, SDL_AudioStreamCallback callback, void *userdata); |
| 1889 | |
| 1890 | /** |
| 1891 | * A callback that fires when data is about to be fed to an audio device. |
| 1892 | * |
| 1893 | * This is useful for accessing the final mix, perhaps for writing a |
| 1894 | * visualizer or applying a final effect to the audio data before playback. |
| 1895 | * |
| 1896 | * This callback should run as quickly as possible and not block for any |
| 1897 | * significant time, as this callback delays submission of data to the audio |
| 1898 | * device, which can cause audio playback problems. |
| 1899 | * |
| 1900 | * The postmix callback _must_ be able to handle any audio data format |
| 1901 | * specified in `spec`, which can change between callbacks if the audio device |
| 1902 | * changed. However, this only covers frequency and channel count; data is |
| 1903 | * always provided here in SDL_AUDIO_F32 format. |
| 1904 | * |
| 1905 | * The postmix callback runs _after_ logical device gain and audiostream gain |
| 1906 | * have been applied, which is to say you can make the output data louder at |
| 1907 | * this point than the gain settings would suggest. |
| 1908 | * |
| 1909 | * \param userdata a pointer provided by the app through |
| 1910 | * SDL_SetAudioPostmixCallback, for its own use. |
| 1911 | * \param spec the current format of audio that is to be submitted to the |
| 1912 | * audio device. |
| 1913 | * \param buffer the buffer of audio samples to be submitted. The callback can |
| 1914 | * inspect and/or modify this data. |
| 1915 | * \param buflen the size of `buffer` in bytes. |
| 1916 | * |
| 1917 | * \threadsafety This will run from a background thread owned by SDL. The |
| 1918 | * application is responsible for locking resources the callback |
| 1919 | * touches that need to be protected. |
| 1920 | * |
| 1921 | * \since This datatype is available since SDL 3.2.0. |
| 1922 | * |
| 1923 | * \sa SDL_SetAudioPostmixCallback |
| 1924 | */ |
| 1925 | typedef void (SDLCALL *SDL_AudioPostmixCallback)(void *userdata, const SDL_AudioSpec *spec, float *buffer, int buflen); |
| 1926 | |
| 1927 | /** |
| 1928 | * Set a callback that fires when data is about to be fed to an audio device. |
| 1929 | * |
| 1930 | * This is useful for accessing the final mix, perhaps for writing a |
| 1931 | * visualizer or applying a final effect to the audio data before playback. |
| 1932 | * |
| 1933 | * The buffer is the final mix of all bound audio streams on an opened device; |
| 1934 | * this callback will fire regularly for any device that is both opened and |
| 1935 | * unpaused. If there is no new data to mix, either because no streams are |
| 1936 | * bound to the device or all the streams are empty, this callback will still |
| 1937 | * fire with the entire buffer set to silence. |
| 1938 | * |
| 1939 | * This callback is allowed to make changes to the data; the contents of the |
| 1940 | * buffer after this call is what is ultimately passed along to the hardware. |
| 1941 | * |
| 1942 | * The callback is always provided the data in float format (values from -1.0f |
| 1943 | * to 1.0f), but the number of channels or sample rate may be different than |
| 1944 | * the format the app requested when opening the device; SDL might have had to |
| 1945 | * manage a conversion behind the scenes, or the playback might have jumped to |
| 1946 | * new physical hardware when a system default changed, etc. These details may |
| 1947 | * change between calls. Accordingly, the size of the buffer might change |
| 1948 | * between calls as well. |
| 1949 | * |
| 1950 | * This callback can run at any time, and from any thread; if you need to |
| 1951 | * serialize access to your app's data, you should provide and use a mutex or |
| 1952 | * other synchronization device. |
| 1953 | * |
| 1954 | * All of this to say: there are specific needs this callback can fulfill, but |
| 1955 | * it is not the simplest interface. Apps should generally provide audio in |
| 1956 | * their preferred format through an SDL_AudioStream and let SDL handle the |
| 1957 | * difference. |
| 1958 | * |
| 1959 | * This function is extremely time-sensitive; the callback should do the least |
| 1960 | * amount of work possible and return as quickly as it can. The longer the |
| 1961 | * callback runs, the higher the risk of audio dropouts or other problems. |
| 1962 | * |
| 1963 | * This function will block until the audio device is in between iterations, |
| 1964 | * so any existing callback that might be running will finish before this |
| 1965 | * function sets the new callback and returns. |
| 1966 | * |
| 1967 | * Setting a NULL callback function disables any previously-set callback. |
| 1968 | * |
| 1969 | * \param devid the ID of an opened audio device. |
| 1970 | * \param callback a callback function to be called. Can be NULL. |
| 1971 | * \param userdata app-controlled pointer passed to callback. Can be NULL. |
| 1972 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 1973 | * information. |
| 1974 | * |
| 1975 | * \threadsafety It is safe to call this function from any thread. |
| 1976 | * |
| 1977 | * \since This function is available since SDL 3.2.0. |
| 1978 | */ |
| 1979 | extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioPostmixCallback(SDL_AudioDeviceID devid, SDL_AudioPostmixCallback callback, void *userdata); |
| 1980 | |
| 1981 | |
| 1982 | /** |
| 1983 | * Load the audio data of a WAVE file into memory. |
| 1984 | * |
| 1985 | * Loading a WAVE file requires `src`, `spec`, `audio_buf` and `audio_len` to |
| 1986 | * be valid pointers. The entire data portion of the file is then loaded into |
| 1987 | * memory and decoded if necessary. |
| 1988 | * |
| 1989 | * Supported formats are RIFF WAVE files with the formats PCM (8, 16, 24, and |
| 1990 | * 32 bits), IEEE Float (32 bits), Microsoft ADPCM and IMA ADPCM (4 bits), and |
| 1991 | * A-law and mu-law (8 bits). Other formats are currently unsupported and |
| 1992 | * cause an error. |
| 1993 | * |
| 1994 | * If this function succeeds, the return value is zero and the pointer to the |
| 1995 | * audio data allocated by the function is written to `audio_buf` and its |
| 1996 | * length in bytes to `audio_len`. The SDL_AudioSpec members `freq`, |
| 1997 | * `channels`, and `format` are set to the values of the audio data in the |
| 1998 | * buffer. |
| 1999 | * |
| 2000 | * It's necessary to use SDL_free() to free the audio data returned in |
| 2001 | * `audio_buf` when it is no longer used. |
| 2002 | * |
| 2003 | * Because of the underspecification of the .WAV format, there are many |
| 2004 | * problematic files in the wild that cause issues with strict decoders. To |
| 2005 | * provide compatibility with these files, this decoder is lenient in regards |
| 2006 | * to the truncation of the file, the fact chunk, and the size of the RIFF |
| 2007 | * chunk. The hints `SDL_HINT_WAVE_RIFF_CHUNK_SIZE`, |
| 2008 | * `SDL_HINT_WAVE_TRUNCATION`, and `SDL_HINT_WAVE_FACT_CHUNK` can be used to |
| 2009 | * tune the behavior of the loading process. |
| 2010 | * |
| 2011 | * Any file that is invalid (due to truncation, corruption, or wrong values in |
| 2012 | * the headers), too big, or unsupported causes an error. Additionally, any |
| 2013 | * critical I/O error from the data source will terminate the loading process |
| 2014 | * with an error. The function returns NULL on error and in all cases (with |
| 2015 | * the exception of `src` being NULL), an appropriate error message will be |
| 2016 | * set. |
| 2017 | * |
| 2018 | * It is required that the data source supports seeking. |
| 2019 | * |
| 2020 | * Example: |
| 2021 | * |
| 2022 | * ```c |
| 2023 | * SDL_LoadWAV_IO(SDL_IOFromFile("sample.wav", "rb"), true, &spec, &buf, &len); |
| 2024 | * ``` |
| 2025 | * |
| 2026 | * Note that the SDL_LoadWAV function does this same thing for you, but in a |
| 2027 | * less messy way: |
| 2028 | * |
| 2029 | * ```c |
| 2030 | * SDL_LoadWAV("sample.wav", &spec, &buf, &len); |
| 2031 | * ``` |
| 2032 | * |
| 2033 | * \param src the data source for the WAVE data. |
| 2034 | * \param closeio if true, calls SDL_CloseIO() on `src` before returning, even |
| 2035 | * in the case of an error. |
| 2036 | * \param spec a pointer to an SDL_AudioSpec that will be set to the WAVE |
| 2037 | * data's format details on successful return. |
| 2038 | * \param audio_buf a pointer filled with the audio data, allocated by the |
| 2039 | * function. |
| 2040 | * \param audio_len a pointer filled with the length of the audio data buffer |
| 2041 | * in bytes. |
| 2042 | * \returns true on success. `audio_buf` will be filled with a pointer to an |
| 2043 | * allocated buffer containing the audio data, and `audio_len` is |
| 2044 | * filled with the length of that audio buffer in bytes. |
| 2045 | * |
| 2046 | * This function returns false if the .WAV file cannot be opened, |
| 2047 | * uses an unknown data format, or is corrupt; call SDL_GetError() |
| 2048 | * for more information. |
| 2049 | * |
| 2050 | * When the application is done with the data returned in |
| 2051 | * `audio_buf`, it should call SDL_free() to dispose of it. |
| 2052 | * |
| 2053 | * \threadsafety It is safe to call this function from any thread. |
| 2054 | * |
| 2055 | * \since This function is available since SDL 3.2.0. |
| 2056 | * |
| 2057 | * \sa SDL_free |
| 2058 | * \sa SDL_LoadWAV |
| 2059 | */ |
| 2060 | extern SDL_DECLSPEC bool SDLCALL SDL_LoadWAV_IO(SDL_IOStream *src, bool closeio, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len); |
| 2061 | |
| 2062 | /** |
| 2063 | * Loads a WAV from a file path. |
| 2064 | * |
| 2065 | * This is a convenience function that is effectively the same as: |
| 2066 | * |
| 2067 | * ```c |
| 2068 | * SDL_LoadWAV_IO(SDL_IOFromFile(path, "rb"), true, spec, audio_buf, audio_len); |
| 2069 | * ``` |
| 2070 | * |
| 2071 | * \param path the file path of the WAV file to open. |
| 2072 | * \param spec a pointer to an SDL_AudioSpec that will be set to the WAVE |
| 2073 | * data's format details on successful return. |
| 2074 | * \param audio_buf a pointer filled with the audio data, allocated by the |
| 2075 | * function. |
| 2076 | * \param audio_len a pointer filled with the length of the audio data buffer |
| 2077 | * in bytes. |
| 2078 | * \returns true on success. `audio_buf` will be filled with a pointer to an |
| 2079 | * allocated buffer containing the audio data, and `audio_len` is |
| 2080 | * filled with the length of that audio buffer in bytes. |
| 2081 | * |
| 2082 | * This function returns false if the .WAV file cannot be opened, |
| 2083 | * uses an unknown data format, or is corrupt; call SDL_GetError() |
| 2084 | * for more information. |
| 2085 | * |
| 2086 | * When the application is done with the data returned in |
| 2087 | * `audio_buf`, it should call SDL_free() to dispose of it. |
| 2088 | * |
| 2089 | * \threadsafety It is safe to call this function from any thread. |
| 2090 | * |
| 2091 | * \since This function is available since SDL 3.2.0. |
| 2092 | * |
| 2093 | * \sa SDL_free |
| 2094 | * \sa SDL_LoadWAV_IO |
| 2095 | */ |
| 2096 | extern SDL_DECLSPEC bool SDLCALL SDL_LoadWAV(const char *path, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len); |
| 2097 | |
| 2098 | /** |
| 2099 | * Mix audio data in a specified format. |
| 2100 | * |
| 2101 | * This takes an audio buffer `src` of `len` bytes of `format` data and mixes |
| 2102 | * it into `dst`, performing addition, volume adjustment, and overflow |
| 2103 | * clipping. The buffer pointed to by `dst` must also be `len` bytes of |
| 2104 | * `format` data. |
| 2105 | * |
| 2106 | * This is provided for convenience -- you can mix your own audio data. |
| 2107 | * |
| 2108 | * Do not use this function for mixing together more than two streams of |
| 2109 | * sample data. The output from repeated application of this function may be |
| 2110 | * distorted by clipping, because there is no accumulator with greater range |
| 2111 | * than the input (not to mention this being an inefficient way of doing it). |
| 2112 | * |
| 2113 | * It is a common misconception that this function is required to write audio |
| 2114 | * data to an output stream in an audio callback. While you can do that, |
| 2115 | * SDL_MixAudio() is really only needed when you're mixing a single audio |
| 2116 | * stream with a volume adjustment. |
| 2117 | * |
| 2118 | * \param dst the destination for the mixed audio. |
| 2119 | * \param src the source audio buffer to be mixed. |
| 2120 | * \param format the SDL_AudioFormat structure representing the desired audio |
| 2121 | * format. |
| 2122 | * \param len the length of the audio buffer in bytes. |
| 2123 | * \param volume ranges from 0.0 - 1.0, and should be set to 1.0 for full |
| 2124 | * audio volume. |
| 2125 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 2126 | * information. |
| 2127 | * |
| 2128 | * \threadsafety It is safe to call this function from any thread. |
| 2129 | * |
| 2130 | * \since This function is available since SDL 3.2.0. |
| 2131 | */ |
| 2132 | extern SDL_DECLSPEC bool SDLCALL SDL_MixAudio(Uint8 *dst, const Uint8 *src, SDL_AudioFormat format, Uint32 len, float volume); |
| 2133 | |
| 2134 | /** |
| 2135 | * Convert some audio data of one format to another format. |
| 2136 | * |
| 2137 | * Please note that this function is for convenience, but should not be used |
| 2138 | * to resample audio in blocks, as it will introduce audio artifacts on the |
| 2139 | * boundaries. You should only use this function if you are converting audio |
| 2140 | * data in its entirety in one call. If you want to convert audio in smaller |
| 2141 | * chunks, use an SDL_AudioStream, which is designed for this situation. |
| 2142 | * |
| 2143 | * Internally, this function creates and destroys an SDL_AudioStream on each |
| 2144 | * use, so it's also less efficient than using one directly, if you need to |
| 2145 | * convert multiple times. |
| 2146 | * |
| 2147 | * \param src_spec the format details of the input audio. |
| 2148 | * \param src_data the audio data to be converted. |
| 2149 | * \param src_len the len of src_data. |
| 2150 | * \param dst_spec the format details of the output audio. |
| 2151 | * \param dst_data will be filled with a pointer to converted audio data, |
| 2152 | * which should be freed with SDL_free(). On error, it will be |
| 2153 | * NULL. |
| 2154 | * \param dst_len will be filled with the len of dst_data. |
| 2155 | * \returns true on success or false on failure; call SDL_GetError() for more |
| 2156 | * information. |
| 2157 | * |
| 2158 | * \threadsafety It is safe to call this function from any thread. |
| 2159 | * |
| 2160 | * \since This function is available since SDL 3.2.0. |
| 2161 | */ |
| 2162 | extern SDL_DECLSPEC bool SDLCALL SDL_ConvertAudioSamples(const SDL_AudioSpec *src_spec, const Uint8 *src_data, int src_len, const SDL_AudioSpec *dst_spec, Uint8 **dst_data, int *dst_len); |
| 2163 | |
| 2164 | /** |
| 2165 | * Get the human readable name of an audio format. |
| 2166 | * |
| 2167 | * \param format the audio format to query. |
| 2168 | * \returns the human readable name of the specified audio format or |
| 2169 | * "SDL_AUDIO_UNKNOWN" if the format isn't recognized. |
| 2170 | * |
| 2171 | * \threadsafety It is safe to call this function from any thread. |
| 2172 | * |
| 2173 | * \since This function is available since SDL 3.2.0. |
| 2174 | */ |
| 2175 | extern SDL_DECLSPEC const char * SDLCALL SDL_GetAudioFormatName(SDL_AudioFormat format); |
| 2176 | |
| 2177 | /** |
| 2178 | * Get the appropriate memset value for silencing an audio format. |
| 2179 | * |
| 2180 | * The value returned by this function can be used as the second argument to |
| 2181 | * memset (or SDL_memset) to set an audio buffer in a specific format to |
| 2182 | * silence. |
| 2183 | * |
| 2184 | * \param format the audio data format to query. |
| 2185 | * \returns a byte value that can be passed to memset. |
| 2186 | * |
| 2187 | * \threadsafety It is safe to call this function from any thread. |
| 2188 | * |
| 2189 | * \since This function is available since SDL 3.2.0. |
| 2190 | */ |
| 2191 | extern SDL_DECLSPEC int SDLCALL SDL_GetSilenceValueForFormat(SDL_AudioFormat format); |
| 2192 | |
| 2193 | |
| 2194 | /* Ends C function definitions when using C++ */ |
| 2195 | #ifdef __cplusplus |
| 2196 | } |
| 2197 | #endif |
| 2198 | #include <SDL3/SDL_close_code.h> |
| 2199 | |
| 2200 | #endif /* SDL_audio_h_ */ |
| 2201 |
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