From 6aaedb813fa11ba0679c3051bc2eb28646b9506c Mon Sep 17 00:00:00 2001 From: 3gg <3gg@shellblade.net> Date: Sat, 30 Aug 2025 16:53:58 -0700 Subject: Update to SDL3 --- src/contrib/SDL-3.2.20/include/SDL3/SDL_audio.h | 2203 +++++++++++++++++++++++ 1 file changed, 2203 insertions(+) create mode 100644 src/contrib/SDL-3.2.20/include/SDL3/SDL_audio.h (limited to 'src/contrib/SDL-3.2.20/include/SDL3/SDL_audio.h') diff --git a/src/contrib/SDL-3.2.20/include/SDL3/SDL_audio.h b/src/contrib/SDL-3.2.20/include/SDL3/SDL_audio.h new file mode 100644 index 0000000..51af40e --- /dev/null +++ b/src/contrib/SDL-3.2.20/include/SDL3/SDL_audio.h @@ -0,0 +1,2203 @@ +/* + Simple DirectMedia Layer + Copyright (C) 1997-2025 Sam Lantinga + + This software is provided 'as-is', without any express or implied + warranty. In no event will the authors be held liable for any damages + arising from the use of this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it + freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + 3. This notice may not be removed or altered from any source distribution. +*/ + +/** + * # CategoryAudio + * + * Audio functionality for the SDL library. + * + * All audio in SDL3 revolves around SDL_AudioStream. Whether you want to play + * or record audio, convert it, stream it, buffer it, or mix it, you're going + * to be passing it through an audio stream. + * + * Audio streams are quite flexible; they can accept any amount of data at a + * time, in any supported format, and output it as needed in any other format, + * even if the data format changes on either side halfway through. + * + * An app opens an audio device and binds any number of audio streams to it, + * feeding more data to the streams as available. When the device needs more + * data, it will pull it from all bound streams and mix them together for + * playback. + * + * Audio streams can also use an app-provided callback to supply data + * on-demand, which maps pretty closely to the SDL2 audio model. + * + * SDL also provides a simple .WAV loader in SDL_LoadWAV (and SDL_LoadWAV_IO + * if you aren't reading from a file) as a basic means to load sound data into + * your program. + * + * ## Logical audio devices + * + * In SDL3, opening a physical device (like a SoundBlaster 16 Pro) gives you a + * logical device ID that you can bind audio streams to. In almost all cases, + * logical devices can be used anywhere in the API that a physical device is + * normally used. However, since each device opening generates a new logical + * device, different parts of the program (say, a VoIP library, or + * text-to-speech framework, or maybe some other sort of mixer on top of SDL) + * can have their own device opens that do not interfere with each other; each + * logical device will mix its separate audio down to a single buffer, fed to + * the physical device, behind the scenes. As many logical devices as you like + * can come and go; SDL will only have to open the physical device at the OS + * level once, and will manage all the logical devices on top of it + * internally. + * + * One other benefit of logical devices: if you don't open a specific physical + * device, instead opting for the default, SDL can automatically migrate those + * logical devices to different hardware as circumstances change: a user + * plugged in headphones? The system default changed? SDL can transparently + * migrate the logical devices to the correct physical device seamlessly and + * keep playing; the app doesn't even have to know it happened if it doesn't + * want to. + * + * ## Simplified audio + * + * As a simplified model for when a single source of audio is all that's + * needed, an app can use SDL_OpenAudioDeviceStream, which is a single + * function to open an audio device, create an audio stream, bind that stream + * to the newly-opened device, and (optionally) provide a callback for + * obtaining audio data. When using this function, the primary interface is + * the SDL_AudioStream and the device handle is mostly hidden away; destroying + * a stream created through this function will also close the device, stream + * bindings cannot be changed, etc. One other quirk of this is that the device + * is started in a _paused_ state and must be explicitly resumed; this is + * partially to offer a clean migration for SDL2 apps and partially because + * the app might have to do more setup before playback begins; in the + * non-simplified form, nothing will play until a stream is bound to a device, + * so they start _unpaused_. + * + * ## Channel layouts + * + * Audio data passing through SDL is uncompressed PCM data, interleaved. One + * can provide their own decompression through an MP3, etc, decoder, but SDL + * does not provide this directly. Each interleaved channel of data is meant + * to be in a specific order. + * + * Abbreviations: + * + * - FRONT = single mono speaker + * - FL = front left speaker + * - FR = front right speaker + * - FC = front center speaker + * - BL = back left speaker + * - BR = back right speaker + * - SR = surround right speaker + * - SL = surround left speaker + * - BC = back center speaker + * - LFE = low-frequency speaker + * + * These are listed in the order they are laid out in memory, so "FL, FR" + * means "the front left speaker is laid out in memory first, then the front + * right, then it repeats for the next audio frame". + * + * - 1 channel (mono) layout: FRONT + * - 2 channels (stereo) layout: FL, FR + * - 3 channels (2.1) layout: FL, FR, LFE + * - 4 channels (quad) layout: FL, FR, BL, BR + * - 5 channels (4.1) layout: FL, FR, LFE, BL, BR + * - 6 channels (5.1) layout: FL, FR, FC, LFE, BL, BR (last two can also be + * SL, SR) + * - 7 channels (6.1) layout: FL, FR, FC, LFE, BC, SL, SR + * - 8 channels (7.1) layout: FL, FR, FC, LFE, BL, BR, SL, SR + * + * This is the same order as DirectSound expects, but applied to all + * platforms; SDL will swizzle the channels as necessary if a platform expects + * something different. + * + * SDL_AudioStream can also be provided channel maps to change this ordering + * to whatever is necessary, in other audio processing scenarios. + */ + +#ifndef SDL_audio_h_ +#define SDL_audio_h_ + +#include +#include +#include +#include +#include +#include + +#include +/* Set up for C function definitions, even when using C++ */ +#ifdef __cplusplus +extern "C" { +#endif + +/** + * Mask of bits in an SDL_AudioFormat that contains the format bit size. + * + * Generally one should use SDL_AUDIO_BITSIZE instead of this macro directly. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_MASK_BITSIZE (0xFFu) + +/** + * Mask of bits in an SDL_AudioFormat that contain the floating point flag. + * + * Generally one should use SDL_AUDIO_ISFLOAT instead of this macro directly. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_MASK_FLOAT (1u<<8) + +/** + * Mask of bits in an SDL_AudioFormat that contain the bigendian flag. + * + * Generally one should use SDL_AUDIO_ISBIGENDIAN or SDL_AUDIO_ISLITTLEENDIAN + * instead of this macro directly. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_MASK_BIG_ENDIAN (1u<<12) + +/** + * Mask of bits in an SDL_AudioFormat that contain the signed data flag. + * + * Generally one should use SDL_AUDIO_ISSIGNED instead of this macro directly. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_MASK_SIGNED (1u<<15) + +/** + * Define an SDL_AudioFormat value. + * + * SDL does not support custom audio formats, so this macro is not of much use + * externally, but it can be illustrative as to what the various bits of an + * SDL_AudioFormat mean. + * + * For example, SDL_AUDIO_S32LE looks like this: + * + * ```c + * SDL_DEFINE_AUDIO_FORMAT(1, 0, 0, 32) + * ``` + * + * \param signed 1 for signed data, 0 for unsigned data. + * \param bigendian 1 for bigendian data, 0 for littleendian data. + * \param flt 1 for floating point data, 0 for integer data. + * \param size number of bits per sample. + * \returns a format value in the style of SDL_AudioFormat. + * + * \threadsafety It is safe to call this macro from any thread. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_DEFINE_AUDIO_FORMAT(signed, bigendian, flt, size) \ + (((Uint16)(signed) << 15) | ((Uint16)(bigendian) << 12) | ((Uint16)(flt) << 8) | ((size) & SDL_AUDIO_MASK_BITSIZE)) + +/** + * Audio format. + * + * \since This enum is available since SDL 3.2.0. + * + * \sa SDL_AUDIO_BITSIZE + * \sa SDL_AUDIO_BYTESIZE + * \sa SDL_AUDIO_ISINT + * \sa SDL_AUDIO_ISFLOAT + * \sa SDL_AUDIO_ISBIGENDIAN + * \sa SDL_AUDIO_ISLITTLEENDIAN + * \sa SDL_AUDIO_ISSIGNED + * \sa SDL_AUDIO_ISUNSIGNED + */ +typedef enum SDL_AudioFormat +{ + SDL_AUDIO_UNKNOWN = 0x0000u, /**< Unspecified audio format */ + SDL_AUDIO_U8 = 0x0008u, /**< Unsigned 8-bit samples */ + /* SDL_DEFINE_AUDIO_FORMAT(0, 0, 0, 8), */ + SDL_AUDIO_S8 = 0x8008u, /**< Signed 8-bit samples */ + /* SDL_DEFINE_AUDIO_FORMAT(1, 0, 0, 8), */ + SDL_AUDIO_S16LE = 0x8010u, /**< Signed 16-bit samples */ + /* SDL_DEFINE_AUDIO_FORMAT(1, 0, 0, 16), */ + SDL_AUDIO_S16BE = 0x9010u, /**< As above, but big-endian byte order */ + /* SDL_DEFINE_AUDIO_FORMAT(1, 1, 0, 16), */ + SDL_AUDIO_S32LE = 0x8020u, /**< 32-bit integer samples */ + /* SDL_DEFINE_AUDIO_FORMAT(1, 0, 0, 32), */ + SDL_AUDIO_S32BE = 0x9020u, /**< As above, but big-endian byte order */ + /* SDL_DEFINE_AUDIO_FORMAT(1, 1, 0, 32), */ + SDL_AUDIO_F32LE = 0x8120u, /**< 32-bit floating point samples */ + /* SDL_DEFINE_AUDIO_FORMAT(1, 0, 1, 32), */ + SDL_AUDIO_F32BE = 0x9120u, /**< As above, but big-endian byte order */ + /* SDL_DEFINE_AUDIO_FORMAT(1, 1, 1, 32), */ + + /* These represent the current system's byteorder. */ + #if SDL_BYTEORDER == SDL_LIL_ENDIAN + SDL_AUDIO_S16 = SDL_AUDIO_S16LE, + SDL_AUDIO_S32 = SDL_AUDIO_S32LE, + SDL_AUDIO_F32 = SDL_AUDIO_F32LE + #else + SDL_AUDIO_S16 = SDL_AUDIO_S16BE, + SDL_AUDIO_S32 = SDL_AUDIO_S32BE, + SDL_AUDIO_F32 = SDL_AUDIO_F32BE + #endif +} SDL_AudioFormat; + + +/** + * Retrieve the size, in bits, from an SDL_AudioFormat. + * + * For example, `SDL_AUDIO_BITSIZE(SDL_AUDIO_S16)` returns 16. + * + * \param x an SDL_AudioFormat value. + * \returns data size in bits. + * + * \threadsafety It is safe to call this macro from any thread. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_BITSIZE(x) ((x) & SDL_AUDIO_MASK_BITSIZE) + +/** + * Retrieve the size, in bytes, from an SDL_AudioFormat. + * + * For example, `SDL_AUDIO_BYTESIZE(SDL_AUDIO_S16)` returns 2. + * + * \param x an SDL_AudioFormat value. + * \returns data size in bytes. + * + * \threadsafety It is safe to call this macro from any thread. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_BYTESIZE(x) (SDL_AUDIO_BITSIZE(x) / 8) + +/** + * Determine if an SDL_AudioFormat represents floating point data. + * + * For example, `SDL_AUDIO_ISFLOAT(SDL_AUDIO_S16)` returns 0. + * + * \param x an SDL_AudioFormat value. + * \returns non-zero if format is floating point, zero otherwise. + * + * \threadsafety It is safe to call this macro from any thread. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_ISFLOAT(x) ((x) & SDL_AUDIO_MASK_FLOAT) + +/** + * Determine if an SDL_AudioFormat represents bigendian data. + * + * For example, `SDL_AUDIO_ISBIGENDIAN(SDL_AUDIO_S16LE)` returns 0. + * + * \param x an SDL_AudioFormat value. + * \returns non-zero if format is bigendian, zero otherwise. + * + * \threadsafety It is safe to call this macro from any thread. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_ISBIGENDIAN(x) ((x) & SDL_AUDIO_MASK_BIG_ENDIAN) + +/** + * Determine if an SDL_AudioFormat represents littleendian data. + * + * For example, `SDL_AUDIO_ISLITTLEENDIAN(SDL_AUDIO_S16BE)` returns 0. + * + * \param x an SDL_AudioFormat value. + * \returns non-zero if format is littleendian, zero otherwise. + * + * \threadsafety It is safe to call this macro from any thread. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_ISLITTLEENDIAN(x) (!SDL_AUDIO_ISBIGENDIAN(x)) + +/** + * Determine if an SDL_AudioFormat represents signed data. + * + * For example, `SDL_AUDIO_ISSIGNED(SDL_AUDIO_U8)` returns 0. + * + * \param x an SDL_AudioFormat value. + * \returns non-zero if format is signed, zero otherwise. + * + * \threadsafety It is safe to call this macro from any thread. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_ISSIGNED(x) ((x) & SDL_AUDIO_MASK_SIGNED) + +/** + * Determine if an SDL_AudioFormat represents integer data. + * + * For example, `SDL_AUDIO_ISINT(SDL_AUDIO_F32)` returns 0. + * + * \param x an SDL_AudioFormat value. + * \returns non-zero if format is integer, zero otherwise. + * + * \threadsafety It is safe to call this macro from any thread. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_ISINT(x) (!SDL_AUDIO_ISFLOAT(x)) + +/** + * Determine if an SDL_AudioFormat represents unsigned data. + * + * For example, `SDL_AUDIO_ISUNSIGNED(SDL_AUDIO_S16)` returns 0. + * + * \param x an SDL_AudioFormat value. + * \returns non-zero if format is unsigned, zero otherwise. + * + * \threadsafety It is safe to call this macro from any thread. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_ISUNSIGNED(x) (!SDL_AUDIO_ISSIGNED(x)) + + +/** + * SDL Audio Device instance IDs. + * + * Zero is used to signify an invalid/null device. + * + * \since This datatype is available since SDL 3.2.0. + */ +typedef Uint32 SDL_AudioDeviceID; + +/** + * A value used to request a default playback audio device. + * + * Several functions that require an SDL_AudioDeviceID will accept this value + * to signify the app just wants the system to choose a default device instead + * of the app providing a specific one. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK ((SDL_AudioDeviceID) 0xFFFFFFFFu) + +/** + * A value used to request a default recording audio device. + * + * Several functions that require an SDL_AudioDeviceID will accept this value + * to signify the app just wants the system to choose a default device instead + * of the app providing a specific one. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_DEVICE_DEFAULT_RECORDING ((SDL_AudioDeviceID) 0xFFFFFFFEu) + +/** + * Format specifier for audio data. + * + * \since This struct is available since SDL 3.2.0. + * + * \sa SDL_AudioFormat + */ +typedef struct SDL_AudioSpec +{ + SDL_AudioFormat format; /**< Audio data format */ + int channels; /**< Number of channels: 1 mono, 2 stereo, etc */ + int freq; /**< sample rate: sample frames per second */ +} SDL_AudioSpec; + +/** + * Calculate the size of each audio frame (in bytes) from an SDL_AudioSpec. + * + * This reports on the size of an audio sample frame: stereo Sint16 data (2 + * channels of 2 bytes each) would be 4 bytes per frame, for example. + * + * \param x an SDL_AudioSpec to query. + * \returns the number of bytes used per sample frame. + * + * \threadsafety It is safe to call this macro from any thread. + * + * \since This macro is available since SDL 3.2.0. + */ +#define SDL_AUDIO_FRAMESIZE(x) (SDL_AUDIO_BYTESIZE((x).format) * (x).channels) + +/** + * The opaque handle that represents an audio stream. + * + * SDL_AudioStream is an audio conversion interface. + * + * - It can handle resampling data in chunks without generating artifacts, + * when it doesn't have the complete buffer available. + * - It can handle incoming data in any variable size. + * - It can handle input/output format changes on the fly. + * - It can remap audio channels between inputs and outputs. + * - You push data as you have it, and pull it when you need it + * - It can also function as a basic audio data queue even if you just have + * sound that needs to pass from one place to another. + * - You can hook callbacks up to them when more data is added or requested, + * to manage data on-the-fly. + * + * Audio streams are the core of the SDL3 audio interface. You create one or + * more of them, bind them to an opened audio device, and feed data to them + * (or for recording, consume data from them). + * + * \since This struct is available since SDL 3.2.0. + * + * \sa SDL_CreateAudioStream + */ +typedef struct SDL_AudioStream SDL_AudioStream; + + +/* Function prototypes */ + +/** + * Use this function to get the number of built-in audio drivers. + * + * This function returns a hardcoded number. This never returns a negative + * value; if there are no drivers compiled into this build of SDL, this + * function returns zero. The presence of a driver in this list does not mean + * it will function, it just means SDL is capable of interacting with that + * interface. For example, a build of SDL might have esound support, but if + * there's no esound server available, SDL's esound driver would fail if used. + * + * By default, SDL tries all drivers, in its preferred order, until one is + * found to be usable. + * + * \returns the number of built-in audio drivers. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_GetAudioDriver + */ +extern SDL_DECLSPEC int SDLCALL SDL_GetNumAudioDrivers(void); + +/** + * Use this function to get the name of a built in audio driver. + * + * The list of audio drivers is given in the order that they are normally + * initialized by default; the drivers that seem more reasonable to choose + * first (as far as the SDL developers believe) are earlier in the list. + * + * The names of drivers are all simple, low-ASCII identifiers, like "alsa", + * "coreaudio" or "wasapi". These never have Unicode characters, and are not + * meant to be proper names. + * + * \param index the index of the audio driver; the value ranges from 0 to + * SDL_GetNumAudioDrivers() - 1. + * \returns the name of the audio driver at the requested index, or NULL if an + * invalid index was specified. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_GetNumAudioDrivers + */ +extern SDL_DECLSPEC const char * SDLCALL SDL_GetAudioDriver(int index); + +/** + * Get the name of the current audio driver. + * + * The names of drivers are all simple, low-ASCII identifiers, like "alsa", + * "coreaudio" or "wasapi". These never have Unicode characters, and are not + * meant to be proper names. + * + * \returns the name of the current audio driver or NULL if no driver has been + * initialized. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +extern SDL_DECLSPEC const char * SDLCALL SDL_GetCurrentAudioDriver(void); + +/** + * Get a list of currently-connected audio playback devices. + * + * This returns of list of available devices that play sound, perhaps to + * speakers or headphones ("playback" devices). If you want devices that + * record audio, like a microphone ("recording" devices), use + * SDL_GetAudioRecordingDevices() instead. + * + * This only returns a list of physical devices; it will not have any device + * IDs returned by SDL_OpenAudioDevice(). + * + * If this function returns NULL, to signify an error, `*count` will be set to + * zero. + * + * \param count a pointer filled in with the number of devices returned, may + * be NULL. + * \returns a 0 terminated array of device instance IDs or NULL on error; call + * SDL_GetError() for more information. This should be freed with + * SDL_free() when it is no longer needed. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_OpenAudioDevice + * \sa SDL_GetAudioRecordingDevices + */ +extern SDL_DECLSPEC SDL_AudioDeviceID * SDLCALL SDL_GetAudioPlaybackDevices(int *count); + +/** + * Get a list of currently-connected audio recording devices. + * + * This returns of list of available devices that record audio, like a + * microphone ("recording" devices). If you want devices that play sound, + * perhaps to speakers or headphones ("playback" devices), use + * SDL_GetAudioPlaybackDevices() instead. + * + * This only returns a list of physical devices; it will not have any device + * IDs returned by SDL_OpenAudioDevice(). + * + * If this function returns NULL, to signify an error, `*count` will be set to + * zero. + * + * \param count a pointer filled in with the number of devices returned, may + * be NULL. + * \returns a 0 terminated array of device instance IDs, or NULL on failure; + * call SDL_GetError() for more information. This should be freed + * with SDL_free() when it is no longer needed. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_OpenAudioDevice + * \sa SDL_GetAudioPlaybackDevices + */ +extern SDL_DECLSPEC SDL_AudioDeviceID * SDLCALL SDL_GetAudioRecordingDevices(int *count); + +/** + * Get the human-readable name of a specific audio device. + * + * \param devid the instance ID of the device to query. + * \returns the name of the audio device, or NULL on failure; call + * SDL_GetError() for more information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_GetAudioPlaybackDevices + * \sa SDL_GetAudioRecordingDevices + */ +extern SDL_DECLSPEC const char * SDLCALL SDL_GetAudioDeviceName(SDL_AudioDeviceID devid); + +/** + * Get the current audio format of a specific audio device. + * + * For an opened device, this will report the format the device is currently + * using. If the device isn't yet opened, this will report the device's + * preferred format (or a reasonable default if this can't be determined). + * + * You may also specify SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK or + * SDL_AUDIO_DEVICE_DEFAULT_RECORDING here, which is useful for getting a + * reasonable recommendation before opening the system-recommended default + * device. + * + * You can also use this to request the current device buffer size. This is + * specified in sample frames and represents the amount of data SDL will feed + * to the physical hardware in each chunk. This can be converted to + * milliseconds of audio with the following equation: + * + * `ms = (int) ((((Sint64) frames) * 1000) / spec.freq);` + * + * Buffer size is only important if you need low-level control over the audio + * playback timing. Most apps do not need this. + * + * \param devid the instance ID of the device to query. + * \param spec on return, will be filled with device details. + * \param sample_frames pointer to store device buffer size, in sample frames. + * Can be NULL. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +extern SDL_DECLSPEC bool SDLCALL SDL_GetAudioDeviceFormat(SDL_AudioDeviceID devid, SDL_AudioSpec *spec, int *sample_frames); + +/** + * Get the current channel map of an audio device. + * + * Channel maps are optional; most things do not need them, instead passing + * data in the [order that SDL expects](CategoryAudio#channel-layouts). + * + * Audio devices usually have no remapping applied. This is represented by + * returning NULL, and does not signify an error. + * + * \param devid the instance ID of the device to query. + * \param count On output, set to number of channels in the map. Can be NULL. + * \returns an array of the current channel mapping, with as many elements as + * the current output spec's channels, or NULL if default. This + * should be freed with SDL_free() when it is no longer needed. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_SetAudioStreamInputChannelMap + */ +extern SDL_DECLSPEC int * SDLCALL SDL_GetAudioDeviceChannelMap(SDL_AudioDeviceID devid, int *count); + +/** + * Open a specific audio device. + * + * You can open both playback and recording devices through this function. + * Playback devices will take data from bound audio streams, mix it, and send + * it to the hardware. Recording devices will feed any bound audio streams + * with a copy of any incoming data. + * + * An opened audio device starts out with no audio streams bound. To start + * audio playing, bind a stream and supply audio data to it. Unlike SDL2, + * there is no audio callback; you only bind audio streams and make sure they + * have data flowing into them (however, you can simulate SDL2's semantics + * fairly closely by using SDL_OpenAudioDeviceStream instead of this + * function). + * + * If you don't care about opening a specific device, pass a `devid` of either + * `SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK` or + * `SDL_AUDIO_DEVICE_DEFAULT_RECORDING`. In this case, SDL will try to pick + * the most reasonable default, and may also switch between physical devices + * seamlessly later, if the most reasonable default changes during the + * lifetime of this opened device (user changed the default in the OS's system + * preferences, the default got unplugged so the system jumped to a new + * default, the user plugged in headphones on a mobile device, etc). Unless + * you have a good reason to choose a specific device, this is probably what + * you want. + * + * You may request a specific format for the audio device, but there is no + * promise the device will honor that request for several reasons. As such, + * it's only meant to be a hint as to what data your app will provide. Audio + * streams will accept data in whatever format you specify and manage + * conversion for you as appropriate. SDL_GetAudioDeviceFormat can tell you + * the preferred format for the device before opening and the actual format + * the device is using after opening. + * + * It's legal to open the same device ID more than once; each successful open + * will generate a new logical SDL_AudioDeviceID that is managed separately + * from others on the same physical device. This allows libraries to open a + * device separately from the main app and bind its own streams without + * conflicting. + * + * It is also legal to open a device ID returned by a previous call to this + * function; doing so just creates another logical device on the same physical + * device. This may be useful for making logical groupings of audio streams. + * + * This function returns the opened device ID on success. This is a new, + * unique SDL_AudioDeviceID that represents a logical device. + * + * Some backends might offer arbitrary devices (for example, a networked audio + * protocol that can connect to an arbitrary server). For these, as a change + * from SDL2, you should open a default device ID and use an SDL hint to + * specify the target if you care, or otherwise let the backend figure out a + * reasonable default. Most backends don't offer anything like this, and often + * this would be an end user setting an environment variable for their custom + * need, and not something an application should specifically manage. + * + * When done with an audio device, possibly at the end of the app's life, one + * should call SDL_CloseAudioDevice() on the returned device id. + * + * \param devid the device instance id to open, or + * SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK or + * SDL_AUDIO_DEVICE_DEFAULT_RECORDING for the most reasonable + * default device. + * \param spec the requested device configuration. Can be NULL to use + * reasonable defaults. + * \returns the device ID on success or 0 on failure; call SDL_GetError() for + * more information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_CloseAudioDevice + * \sa SDL_GetAudioDeviceFormat + */ +extern SDL_DECLSPEC SDL_AudioDeviceID SDLCALL SDL_OpenAudioDevice(SDL_AudioDeviceID devid, const SDL_AudioSpec *spec); + +/** + * Determine if an audio device is physical (instead of logical). + * + * An SDL_AudioDeviceID that represents physical hardware is a physical + * device; there is one for each piece of hardware that SDL can see. Logical + * devices are created by calling SDL_OpenAudioDevice or + * SDL_OpenAudioDeviceStream, and while each is associated with a physical + * device, there can be any number of logical devices on one physical device. + * + * For the most part, logical and physical IDs are interchangeable--if you try + * to open a logical device, SDL understands to assign that effort to the + * underlying physical device, etc. However, it might be useful to know if an + * arbitrary device ID is physical or logical. This function reports which. + * + * This function may return either true or false for invalid device IDs. + * + * \param devid the device ID to query. + * \returns true if devid is a physical device, false if it is logical. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +extern SDL_DECLSPEC bool SDLCALL SDL_IsAudioDevicePhysical(SDL_AudioDeviceID devid); + +/** + * Determine if an audio device is a playback device (instead of recording). + * + * This function may return either true or false for invalid device IDs. + * + * \param devid the device ID to query. + * \returns true if devid is a playback device, false if it is recording. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +extern SDL_DECLSPEC bool SDLCALL SDL_IsAudioDevicePlayback(SDL_AudioDeviceID devid); + +/** + * Use this function to pause audio playback on a specified device. + * + * This function pauses audio processing for a given device. Any bound audio + * streams will not progress, and no audio will be generated. Pausing one + * device does not prevent other unpaused devices from running. + * + * Unlike in SDL2, audio devices start in an _unpaused_ state, since an app + * has to bind a stream before any audio will flow. Pausing a paused device is + * a legal no-op. + * + * Pausing a device can be useful to halt all audio without unbinding all the + * audio streams. This might be useful while a game is paused, or a level is + * loading, etc. + * + * Physical devices can not be paused or unpaused, only logical devices + * created through SDL_OpenAudioDevice() can be. + * + * \param devid a device opened by SDL_OpenAudioDevice(). + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_ResumeAudioDevice + * \sa SDL_AudioDevicePaused + */ +extern SDL_DECLSPEC bool SDLCALL SDL_PauseAudioDevice(SDL_AudioDeviceID devid); + +/** + * Use this function to unpause audio playback on a specified device. + * + * This function unpauses audio processing for a given device that has + * previously been paused with SDL_PauseAudioDevice(). Once unpaused, any + * bound audio streams will begin to progress again, and audio can be + * generated. + * + * Unlike in SDL2, audio devices start in an _unpaused_ state, since an app + * has to bind a stream before any audio will flow. Unpausing an unpaused + * device is a legal no-op. + * + * Physical devices can not be paused or unpaused, only logical devices + * created through SDL_OpenAudioDevice() can be. + * + * \param devid a device opened by SDL_OpenAudioDevice(). + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_AudioDevicePaused + * \sa SDL_PauseAudioDevice + */ +extern SDL_DECLSPEC bool SDLCALL SDL_ResumeAudioDevice(SDL_AudioDeviceID devid); + +/** + * Use this function to query if an audio device is paused. + * + * Unlike in SDL2, audio devices start in an _unpaused_ state, since an app + * has to bind a stream before any audio will flow. + * + * Physical devices can not be paused or unpaused, only logical devices + * created through SDL_OpenAudioDevice() can be. Physical and invalid device + * IDs will report themselves as unpaused here. + * + * \param devid a device opened by SDL_OpenAudioDevice(). + * \returns true if device is valid and paused, false otherwise. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_PauseAudioDevice + * \sa SDL_ResumeAudioDevice + */ +extern SDL_DECLSPEC bool SDLCALL SDL_AudioDevicePaused(SDL_AudioDeviceID devid); + +/** + * Get the gain of an audio device. + * + * The gain of a device is its volume; a larger gain means a louder output, + * with a gain of zero being silence. + * + * Audio devices default to a gain of 1.0f (no change in output). + * + * Physical devices may not have their gain changed, only logical devices, and + * this function will always return -1.0f when used on physical devices. + * + * \param devid the audio device to query. + * \returns the gain of the device or -1.0f on failure; call SDL_GetError() + * for more information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_SetAudioDeviceGain + */ +extern SDL_DECLSPEC float SDLCALL SDL_GetAudioDeviceGain(SDL_AudioDeviceID devid); + +/** + * Change the gain of an audio device. + * + * The gain of a device is its volume; a larger gain means a louder output, + * with a gain of zero being silence. + * + * Audio devices default to a gain of 1.0f (no change in output). + * + * Physical devices may not have their gain changed, only logical devices, and + * this function will always return false when used on physical devices. While + * it might seem attractive to adjust several logical devices at once in this + * way, it would allow an app or library to interfere with another portion of + * the program's otherwise-isolated devices. + * + * This is applied, along with any per-audiostream gain, during playback to + * the hardware, and can be continuously changed to create various effects. On + * recording devices, this will adjust the gain before passing the data into + * an audiostream; that recording audiostream can then adjust its gain further + * when outputting the data elsewhere, if it likes, but that second gain is + * not applied until the data leaves the audiostream again. + * + * \param devid the audio device on which to change gain. + * \param gain the gain. 1.0f is no change, 0.0f is silence. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread, as it holds + * a stream-specific mutex while running. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_GetAudioDeviceGain + */ +extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioDeviceGain(SDL_AudioDeviceID devid, float gain); + +/** + * Close a previously-opened audio device. + * + * The application should close open audio devices once they are no longer + * needed. + * + * This function may block briefly while pending audio data is played by the + * hardware, so that applications don't drop the last buffer of data they + * supplied if terminating immediately afterwards. + * + * \param devid an audio device id previously returned by + * SDL_OpenAudioDevice(). + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_OpenAudioDevice + */ +extern SDL_DECLSPEC void SDLCALL SDL_CloseAudioDevice(SDL_AudioDeviceID devid); + +/** + * Bind a list of audio streams to an audio device. + * + * Audio data will flow through any bound streams. For a playback device, data + * for all bound streams will be mixed together and fed to the device. For a + * recording device, a copy of recorded data will be provided to each bound + * stream. + * + * Audio streams can only be bound to an open device. This operation is + * atomic--all streams bound in the same call will start processing at the + * same time, so they can stay in sync. Also: either all streams will be bound + * or none of them will be. + * + * It is an error to bind an already-bound stream; it must be explicitly + * unbound first. + * + * Binding a stream to a device will set its output format for playback + * devices, and its input format for recording devices, so they match the + * device's settings. The caller is welcome to change the other end of the + * stream's format at any time with SDL_SetAudioStreamFormat(). If the other + * end of the stream's format has never been set (the audio stream was created + * with a NULL audio spec), this function will set it to match the device + * end's format. + * + * \param devid an audio device to bind a stream to. + * \param streams an array of audio streams to bind. + * \param num_streams number streams listed in the `streams` array. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_BindAudioStreams + * \sa SDL_UnbindAudioStream + * \sa SDL_GetAudioStreamDevice + */ +extern SDL_DECLSPEC bool SDLCALL SDL_BindAudioStreams(SDL_AudioDeviceID devid, SDL_AudioStream * const *streams, int num_streams); + +/** + * Bind a single audio stream to an audio device. + * + * This is a convenience function, equivalent to calling + * `SDL_BindAudioStreams(devid, &stream, 1)`. + * + * \param devid an audio device to bind a stream to. + * \param stream an audio stream to bind to a device. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_BindAudioStreams + * \sa SDL_UnbindAudioStream + * \sa SDL_GetAudioStreamDevice + */ +extern SDL_DECLSPEC bool SDLCALL SDL_BindAudioStream(SDL_AudioDeviceID devid, SDL_AudioStream *stream); + +/** + * Unbind a list of audio streams from their audio devices. + * + * The streams being unbound do not all have to be on the same device. All + * streams on the same device will be unbound atomically (data will stop + * flowing through all unbound streams on the same device at the same time). + * + * Unbinding a stream that isn't bound to a device is a legal no-op. + * + * \param streams an array of audio streams to unbind. Can be NULL or contain + * NULL. + * \param num_streams number streams listed in the `streams` array. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_BindAudioStreams + */ +extern SDL_DECLSPEC void SDLCALL SDL_UnbindAudioStreams(SDL_AudioStream * const *streams, int num_streams); + +/** + * Unbind a single audio stream from its audio device. + * + * This is a convenience function, equivalent to calling + * `SDL_UnbindAudioStreams(&stream, 1)`. + * + * \param stream an audio stream to unbind from a device. Can be NULL. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_BindAudioStream + */ +extern SDL_DECLSPEC void SDLCALL SDL_UnbindAudioStream(SDL_AudioStream *stream); + +/** + * Query an audio stream for its currently-bound device. + * + * This reports the logical audio device that an audio stream is currently bound to. + * + * If not bound, or invalid, this returns zero, which is not a valid device + * ID. + * + * \param stream the audio stream to query. + * \returns the bound audio device, or 0 if not bound or invalid. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_BindAudioStream + * \sa SDL_BindAudioStreams + */ +extern SDL_DECLSPEC SDL_AudioDeviceID SDLCALL SDL_GetAudioStreamDevice(SDL_AudioStream *stream); + +/** + * Create a new audio stream. + * + * \param src_spec the format details of the input audio. + * \param dst_spec the format details of the output audio. + * \returns a new audio stream on success or NULL on failure; call + * SDL_GetError() for more information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_PutAudioStreamData + * \sa SDL_GetAudioStreamData + * \sa SDL_GetAudioStreamAvailable + * \sa SDL_FlushAudioStream + * \sa SDL_ClearAudioStream + * \sa SDL_SetAudioStreamFormat + * \sa SDL_DestroyAudioStream + */ +extern SDL_DECLSPEC SDL_AudioStream * SDLCALL SDL_CreateAudioStream(const SDL_AudioSpec *src_spec, const SDL_AudioSpec *dst_spec); + +/** + * Get the properties associated with an audio stream. + * + * \param stream the SDL_AudioStream to query. + * \returns a valid property ID on success or 0 on failure; call + * SDL_GetError() for more information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +extern SDL_DECLSPEC SDL_PropertiesID SDLCALL SDL_GetAudioStreamProperties(SDL_AudioStream *stream); + +/** + * Query the current format of an audio stream. + * + * \param stream the SDL_AudioStream to query. + * \param src_spec where to store the input audio format; ignored if NULL. + * \param dst_spec where to store the output audio format; ignored if NULL. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread, as it holds + * a stream-specific mutex while running. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_SetAudioStreamFormat + */ +extern SDL_DECLSPEC bool SDLCALL SDL_GetAudioStreamFormat(SDL_AudioStream *stream, SDL_AudioSpec *src_spec, SDL_AudioSpec *dst_spec); + +/** + * Change the input and output formats of an audio stream. + * + * Future calls to and SDL_GetAudioStreamAvailable and SDL_GetAudioStreamData + * will reflect the new format, and future calls to SDL_PutAudioStreamData + * must provide data in the new input formats. + * + * Data that was previously queued in the stream will still be operated on in + * the format that was current when it was added, which is to say you can put + * the end of a sound file in one format to a stream, change formats for the + * next sound file, and start putting that new data while the previous sound + * file is still queued, and everything will still play back correctly. + * + * If a stream is bound to a device, then the format of the side of the stream + * bound to a device cannot be changed (src_spec for recording devices, + * dst_spec for playback devices). Attempts to make a change to this side will + * be ignored, but this will not report an error. The other side's format can + * be changed. + * + * \param stream the stream the format is being changed. + * \param src_spec the new format of the audio input; if NULL, it is not + * changed. + * \param dst_spec the new format of the audio output; if NULL, it is not + * changed. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread, as it holds + * a stream-specific mutex while running. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_GetAudioStreamFormat + * \sa SDL_SetAudioStreamFrequencyRatio + */ +extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamFormat(SDL_AudioStream *stream, const SDL_AudioSpec *src_spec, const SDL_AudioSpec *dst_spec); + +/** + * Get the frequency ratio of an audio stream. + * + * \param stream the SDL_AudioStream to query. + * \returns the frequency ratio of the stream or 0.0 on failure; call + * SDL_GetError() for more information. + * + * \threadsafety It is safe to call this function from any thread, as it holds + * a stream-specific mutex while running. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_SetAudioStreamFrequencyRatio + */ +extern SDL_DECLSPEC float SDLCALL SDL_GetAudioStreamFrequencyRatio(SDL_AudioStream *stream); + +/** + * Change the frequency ratio of an audio stream. + * + * The frequency ratio is used to adjust the rate at which input data is + * consumed. Changing this effectively modifies the speed and pitch of the + * audio. A value greater than 1.0 will play the audio faster, and at a higher + * pitch. A value less than 1.0 will play the audio slower, and at a lower + * pitch. + * + * This is applied during SDL_GetAudioStreamData, and can be continuously + * changed to create various effects. + * + * \param stream the stream the frequency ratio is being changed. + * \param ratio the frequency ratio. 1.0 is normal speed. Must be between 0.01 + * and 100. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread, as it holds + * a stream-specific mutex while running. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_GetAudioStreamFrequencyRatio + * \sa SDL_SetAudioStreamFormat + */ +extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamFrequencyRatio(SDL_AudioStream *stream, float ratio); + +/** + * Get the gain of an audio stream. + * + * The gain of a stream is its volume; a larger gain means a louder output, + * with a gain of zero being silence. + * + * Audio streams default to a gain of 1.0f (no change in output). + * + * \param stream the SDL_AudioStream to query. + * \returns the gain of the stream or -1.0f on failure; call SDL_GetError() + * for more information. + * + * \threadsafety It is safe to call this function from any thread, as it holds + * a stream-specific mutex while running. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_SetAudioStreamGain + */ +extern SDL_DECLSPEC float SDLCALL SDL_GetAudioStreamGain(SDL_AudioStream *stream); + +/** + * Change the gain of an audio stream. + * + * The gain of a stream is its volume; a larger gain means a louder output, + * with a gain of zero being silence. + * + * Audio streams default to a gain of 1.0f (no change in output). + * + * This is applied during SDL_GetAudioStreamData, and can be continuously + * changed to create various effects. + * + * \param stream the stream on which the gain is being changed. + * \param gain the gain. 1.0f is no change, 0.0f is silence. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread, as it holds + * a stream-specific mutex while running. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_GetAudioStreamGain + */ +extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamGain(SDL_AudioStream *stream, float gain); + +/** + * Get the current input channel map of an audio stream. + * + * Channel maps are optional; most things do not need them, instead passing + * data in the [order that SDL expects](CategoryAudio#channel-layouts). + * + * Audio streams default to no remapping applied. This is represented by + * returning NULL, and does not signify an error. + * + * \param stream the SDL_AudioStream to query. + * \param count On output, set to number of channels in the map. Can be NULL. + * \returns an array of the current channel mapping, with as many elements as + * the current output spec's channels, or NULL if default. This + * should be freed with SDL_free() when it is no longer needed. + * + * \threadsafety It is safe to call this function from any thread, as it holds + * a stream-specific mutex while running. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_SetAudioStreamInputChannelMap + */ +extern SDL_DECLSPEC int * SDLCALL SDL_GetAudioStreamInputChannelMap(SDL_AudioStream *stream, int *count); + +/** + * Get the current output channel map of an audio stream. + * + * Channel maps are optional; most things do not need them, instead passing + * data in the [order that SDL expects](CategoryAudio#channel-layouts). + * + * Audio streams default to no remapping applied. This is represented by + * returning NULL, and does not signify an error. + * + * \param stream the SDL_AudioStream to query. + * \param count On output, set to number of channels in the map. Can be NULL. + * \returns an array of the current channel mapping, with as many elements as + * the current output spec's channels, or NULL if default. This + * should be freed with SDL_free() when it is no longer needed. + * + * \threadsafety It is safe to call this function from any thread, as it holds + * a stream-specific mutex while running. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_SetAudioStreamInputChannelMap + */ +extern SDL_DECLSPEC int * SDLCALL SDL_GetAudioStreamOutputChannelMap(SDL_AudioStream *stream, int *count); + +/** + * Set the current input channel map of an audio stream. + * + * Channel maps are optional; most things do not need them, instead passing + * data in the [order that SDL expects](CategoryAudio#channel-layouts). + * + * The input channel map reorders data that is added to a stream via + * SDL_PutAudioStreamData. Future calls to SDL_PutAudioStreamData must provide + * data in the new channel order. + * + * Each item in the array represents an input channel, and its value is the + * channel that it should be remapped to. To reverse a stereo signal's left + * and right values, you'd have an array of `{ 1, 0 }`. It is legal to remap + * multiple channels to the same thing, so `{ 1, 1 }` would duplicate the + * right channel to both channels of a stereo signal. An element in the + * channel map set to -1 instead of a valid channel will mute that channel, + * setting it to a silence value. + * + * You cannot change the number of channels through a channel map, just + * reorder/mute them. + * + * Data that was previously queued in the stream will still be operated on in + * the order that was current when it was added, which is to say you can put + * the end of a sound file in one order to a stream, change orders for the + * next sound file, and start putting that new data while the previous sound + * file is still queued, and everything will still play back correctly. + * + * Audio streams default to no remapping applied. Passing a NULL channel map + * is legal, and turns off remapping. + * + * SDL will copy the channel map; the caller does not have to save this array + * after this call. + * + * If `count` is not equal to the current number of channels in the audio + * stream's format, this will fail. This is a safety measure to make sure a + * race condition hasn't changed the format while this call is setting the + * channel map. + * + * Unlike attempting to change the stream's format, the input channel map on a + * stream bound to a recording device is permitted to change at any time; any + * data added to the stream from the device after this call will have the new + * mapping, but previously-added data will still have the prior mapping. + * + * \param stream the SDL_AudioStream to change. + * \param chmap the new channel map, NULL to reset to default. + * \param count The number of channels in the map. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread, as it holds + * a stream-specific mutex while running. Don't change the + * stream's format to have a different number of channels from a + * a different thread at the same time, though! + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_SetAudioStreamInputChannelMap + */ +extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamInputChannelMap(SDL_AudioStream *stream, const int *chmap, int count); + +/** + * Set the current output channel map of an audio stream. + * + * Channel maps are optional; most things do not need them, instead passing + * data in the [order that SDL expects](CategoryAudio#channel-layouts). + * + * The output channel map reorders data that leaving a stream via + * SDL_GetAudioStreamData. + * + * Each item in the array represents an input channel, and its value is the + * channel that it should be remapped to. To reverse a stereo signal's left + * and right values, you'd have an array of `{ 1, 0 }`. It is legal to remap + * multiple channels to the same thing, so `{ 1, 1 }` would duplicate the + * right channel to both channels of a stereo signal. An element in the + * channel map set to -1 instead of a valid channel will mute that channel, + * setting it to a silence value. + * + * You cannot change the number of channels through a channel map, just + * reorder/mute them. + * + * The output channel map can be changed at any time, as output remapping is + * applied during SDL_GetAudioStreamData. + * + * Audio streams default to no remapping applied. Passing a NULL channel map + * is legal, and turns off remapping. + * + * SDL will copy the channel map; the caller does not have to save this array + * after this call. + * + * If `count` is not equal to the current number of channels in the audio + * stream's format, this will fail. This is a safety measure to make sure a + * race condition hasn't changed the format while this call is setting the + * channel map. + * + * Unlike attempting to change the stream's format, the output channel map on + * a stream bound to a recording device is permitted to change at any time; + * any data added to the stream after this call will have the new mapping, but + * previously-added data will still have the prior mapping. When the channel + * map doesn't match the hardware's channel layout, SDL will convert the data + * before feeding it to the device for playback. + * + * \param stream the SDL_AudioStream to change. + * \param chmap the new channel map, NULL to reset to default. + * \param count The number of channels in the map. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread, as it holds + * a stream-specific mutex while running. Don't change the + * stream's format to have a different number of channels from a + * a different thread at the same time, though! + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_SetAudioStreamInputChannelMap + */ +extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamOutputChannelMap(SDL_AudioStream *stream, const int *chmap, int count); + +/** + * Add data to the stream. + * + * This data must match the format/channels/samplerate specified in the latest + * call to SDL_SetAudioStreamFormat, or the format specified when creating the + * stream if it hasn't been changed. + * + * Note that this call simply copies the unconverted data for later. This is + * different than SDL2, where data was converted during the Put call and the + * Get call would just dequeue the previously-converted data. + * + * \param stream the stream the audio data is being added to. + * \param buf a pointer to the audio data to add. + * \param len the number of bytes to write to the stream. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread, but if the + * stream has a callback set, the caller might need to manage + * extra locking. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_ClearAudioStream + * \sa SDL_FlushAudioStream + * \sa SDL_GetAudioStreamData + * \sa SDL_GetAudioStreamQueued + */ +extern SDL_DECLSPEC bool SDLCALL SDL_PutAudioStreamData(SDL_AudioStream *stream, const void *buf, int len); + +/** + * Get converted/resampled data from the stream. + * + * The input/output data format/channels/samplerate is specified when creating + * the stream, and can be changed after creation by calling + * SDL_SetAudioStreamFormat. + * + * Note that any conversion and resampling necessary is done during this call, + * and SDL_PutAudioStreamData simply queues unconverted data for later. This + * is different than SDL2, where that work was done while inputting new data + * to the stream and requesting the output just copied the converted data. + * + * \param stream the stream the audio is being requested from. + * \param buf a buffer to fill with audio data. + * \param len the maximum number of bytes to fill. + * \returns the number of bytes read from the stream or -1 on failure; call + * SDL_GetError() for more information. + * + * \threadsafety It is safe to call this function from any thread, but if the + * stream has a callback set, the caller might need to manage + * extra locking. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_ClearAudioStream + * \sa SDL_GetAudioStreamAvailable + * \sa SDL_PutAudioStreamData + */ +extern SDL_DECLSPEC int SDLCALL SDL_GetAudioStreamData(SDL_AudioStream *stream, void *buf, int len); + +/** + * Get the number of converted/resampled bytes available. + * + * The stream may be buffering data behind the scenes until it has enough to + * resample correctly, so this number might be lower than what you expect, or + * even be zero. Add more data or flush the stream if you need the data now. + * + * If the stream has so much data that it would overflow an int, the return + * value is clamped to a maximum value, but no queued data is lost; if there + * are gigabytes of data queued, the app might need to read some of it with + * SDL_GetAudioStreamData before this function's return value is no longer + * clamped. + * + * \param stream the audio stream to query. + * \returns the number of converted/resampled bytes available or -1 on + * failure; call SDL_GetError() for more information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_GetAudioStreamData + * \sa SDL_PutAudioStreamData + */ +extern SDL_DECLSPEC int SDLCALL SDL_GetAudioStreamAvailable(SDL_AudioStream *stream); + + +/** + * Get the number of bytes currently queued. + * + * This is the number of bytes put into a stream as input, not the number that + * can be retrieved as output. Because of several details, it's not possible + * to calculate one number directly from the other. If you need to know how + * much usable data can be retrieved right now, you should use + * SDL_GetAudioStreamAvailable() and not this function. + * + * Note that audio streams can change their input format at any time, even if + * there is still data queued in a different format, so the returned byte + * count will not necessarily match the number of _sample frames_ available. + * Users of this API should be aware of format changes they make when feeding + * a stream and plan accordingly. + * + * Queued data is not converted until it is consumed by + * SDL_GetAudioStreamData, so this value should be representative of the exact + * data that was put into the stream. + * + * If the stream has so much data that it would overflow an int, the return + * value is clamped to a maximum value, but no queued data is lost; if there + * are gigabytes of data queued, the app might need to read some of it with + * SDL_GetAudioStreamData before this function's return value is no longer + * clamped. + * + * \param stream the audio stream to query. + * \returns the number of bytes queued or -1 on failure; call SDL_GetError() + * for more information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_PutAudioStreamData + * \sa SDL_ClearAudioStream + */ +extern SDL_DECLSPEC int SDLCALL SDL_GetAudioStreamQueued(SDL_AudioStream *stream); + + +/** + * Tell the stream that you're done sending data, and anything being buffered + * should be converted/resampled and made available immediately. + * + * It is legal to add more data to a stream after flushing, but there may be + * audio gaps in the output. Generally this is intended to signal the end of + * input, so the complete output becomes available. + * + * \param stream the audio stream to flush. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_PutAudioStreamData + */ +extern SDL_DECLSPEC bool SDLCALL SDL_FlushAudioStream(SDL_AudioStream *stream); + +/** + * Clear any pending data in the stream. + * + * This drops any queued data, so there will be nothing to read from the + * stream until more is added. + * + * \param stream the audio stream to clear. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_GetAudioStreamAvailable + * \sa SDL_GetAudioStreamData + * \sa SDL_GetAudioStreamQueued + * \sa SDL_PutAudioStreamData + */ +extern SDL_DECLSPEC bool SDLCALL SDL_ClearAudioStream(SDL_AudioStream *stream); + +/** + * Use this function to pause audio playback on the audio device associated + * with an audio stream. + * + * This function pauses audio processing for a given device. Any bound audio + * streams will not progress, and no audio will be generated. Pausing one + * device does not prevent other unpaused devices from running. + * + * Pausing a device can be useful to halt all audio without unbinding all the + * audio streams. This might be useful while a game is paused, or a level is + * loading, etc. + * + * \param stream the audio stream associated with the audio device to pause. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_ResumeAudioStreamDevice + */ +extern SDL_DECLSPEC bool SDLCALL SDL_PauseAudioStreamDevice(SDL_AudioStream *stream); + +/** + * Use this function to unpause audio playback on the audio device associated + * with an audio stream. + * + * This function unpauses audio processing for a given device that has + * previously been paused. Once unpaused, any bound audio streams will begin + * to progress again, and audio can be generated. + * + * Remember, SDL_OpenAudioDeviceStream opens device in a paused state, so this + * function call is required for audio playback to begin on such device. + * + * \param stream the audio stream associated with the audio device to resume. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_PauseAudioStreamDevice + */ +extern SDL_DECLSPEC bool SDLCALL SDL_ResumeAudioStreamDevice(SDL_AudioStream *stream); + +/** + * Use this function to query if an audio device associated with a stream is + * paused. + * + * Unlike in SDL2, audio devices start in an _unpaused_ state, since an app + * has to bind a stream before any audio will flow. + * + * \param stream the audio stream associated with the audio device to query. + * \returns true if device is valid and paused, false otherwise. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_PauseAudioStreamDevice + * \sa SDL_ResumeAudioStreamDevice + */ +extern SDL_DECLSPEC bool SDLCALL SDL_AudioStreamDevicePaused(SDL_AudioStream *stream); + + +/** + * Lock an audio stream for serialized access. + * + * Each SDL_AudioStream has an internal mutex it uses to protect its data + * structures from threading conflicts. This function allows an app to lock + * that mutex, which could be useful if registering callbacks on this stream. + * + * One does not need to lock a stream to use in it most cases, as the stream + * manages this lock internally. However, this lock is held during callbacks, + * which may run from arbitrary threads at any time, so if an app needs to + * protect shared data during those callbacks, locking the stream guarantees + * that the callback is not running while the lock is held. + * + * As this is just a wrapper over SDL_LockMutex for an internal lock; it has + * all the same attributes (recursive locks are allowed, etc). + * + * \param stream the audio stream to lock. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_UnlockAudioStream + */ +extern SDL_DECLSPEC bool SDLCALL SDL_LockAudioStream(SDL_AudioStream *stream); + + +/** + * Unlock an audio stream for serialized access. + * + * This unlocks an audio stream after a call to SDL_LockAudioStream. + * + * \param stream the audio stream to unlock. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety You should only call this from the same thread that + * previously called SDL_LockAudioStream. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_LockAudioStream + */ +extern SDL_DECLSPEC bool SDLCALL SDL_UnlockAudioStream(SDL_AudioStream *stream); + +/** + * A callback that fires when data passes through an SDL_AudioStream. + * + * Apps can (optionally) register a callback with an audio stream that is + * called when data is added with SDL_PutAudioStreamData, or requested with + * SDL_GetAudioStreamData. + * + * Two values are offered here: one is the amount of additional data needed to + * satisfy the immediate request (which might be zero if the stream already + * has enough data queued) and the other is the total amount being requested. + * In a Get call triggering a Put callback, these values can be different. In + * a Put call triggering a Get callback, these values are always the same. + * + * Byte counts might be slightly overestimated due to buffering or resampling, + * and may change from call to call. + * + * This callback is not required to do anything. Generally this is useful for + * adding/reading data on demand, and the app will often put/get data as + * appropriate, but the system goes on with the data currently available to it + * if this callback does nothing. + * + * \param stream the SDL audio stream associated with this callback. + * \param additional_amount the amount of data, in bytes, that is needed right + * now. + * \param total_amount the total amount of data requested, in bytes, that is + * requested or available. + * \param userdata an opaque pointer provided by the app for their personal + * use. + * + * \threadsafety This callbacks may run from any thread, so if you need to + * protect shared data, you should use SDL_LockAudioStream to + * serialize access; this lock will be held before your callback + * is called, so your callback does not need to manage the lock + * explicitly. + * + * \since This datatype is available since SDL 3.2.0. + * + * \sa SDL_SetAudioStreamGetCallback + * \sa SDL_SetAudioStreamPutCallback + */ +typedef void (SDLCALL *SDL_AudioStreamCallback)(void *userdata, SDL_AudioStream *stream, int additional_amount, int total_amount); + +/** + * Set a callback that runs when data is requested from an audio stream. + * + * This callback is called _before_ data is obtained from the stream, giving + * the callback the chance to add more on-demand. + * + * The callback can (optionally) call SDL_PutAudioStreamData() to add more + * audio to the stream during this call; if needed, the request that triggered + * this callback will obtain the new data immediately. + * + * The callback's `additional_amount` argument is roughly how many bytes of + * _unconverted_ data (in the stream's input format) is needed by the caller, + * although this may overestimate a little for safety. This takes into account + * how much is already in the stream and only asks for any extra necessary to + * resolve the request, which means the callback may be asked for zero bytes, + * and a different amount on each call. + * + * The callback is not required to supply exact amounts; it is allowed to + * supply too much or too little or none at all. The caller will get what's + * available, up to the amount they requested, regardless of this callback's + * outcome. + * + * Clearing or flushing an audio stream does not call this callback. + * + * This function obtains the stream's lock, which means any existing callback + * (get or put) in progress will finish running before setting the new + * callback. + * + * Setting a NULL function turns off the callback. + * + * \param stream the audio stream to set the new callback on. + * \param callback the new callback function to call when data is requested + * from the stream. + * \param userdata an opaque pointer provided to the callback for its own + * personal use. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. This only fails if `stream` is NULL. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_SetAudioStreamPutCallback + */ +extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamGetCallback(SDL_AudioStream *stream, SDL_AudioStreamCallback callback, void *userdata); + +/** + * Set a callback that runs when data is added to an audio stream. + * + * This callback is called _after_ the data is added to the stream, giving the + * callback the chance to obtain it immediately. + * + * The callback can (optionally) call SDL_GetAudioStreamData() to obtain audio + * from the stream during this call. + * + * The callback's `additional_amount` argument is how many bytes of + * _converted_ data (in the stream's output format) was provided by the + * caller, although this may underestimate a little for safety. This value + * might be less than what is currently available in the stream, if data was + * already there, and might be less than the caller provided if the stream + * needs to keep a buffer to aid in resampling. Which means the callback may + * be provided with zero bytes, and a different amount on each call. + * + * The callback may call SDL_GetAudioStreamAvailable to see the total amount + * currently available to read from the stream, instead of the total provided + * by the current call. + * + * The callback is not required to obtain all data. It is allowed to read less + * or none at all. Anything not read now simply remains in the stream for + * later access. + * + * Clearing or flushing an audio stream does not call this callback. + * + * This function obtains the stream's lock, which means any existing callback + * (get or put) in progress will finish running before setting the new + * callback. + * + * Setting a NULL function turns off the callback. + * + * \param stream the audio stream to set the new callback on. + * \param callback the new callback function to call when data is added to the + * stream. + * \param userdata an opaque pointer provided to the callback for its own + * personal use. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. This only fails if `stream` is NULL. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_SetAudioStreamGetCallback + */ +extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioStreamPutCallback(SDL_AudioStream *stream, SDL_AudioStreamCallback callback, void *userdata); + + +/** + * Free an audio stream. + * + * This will release all allocated data, including any audio that is still + * queued. You do not need to manually clear the stream first. + * + * If this stream was bound to an audio device, it is unbound during this + * call. If this stream was created with SDL_OpenAudioDeviceStream, the audio + * device that was opened alongside this stream's creation will be closed, + * too. + * + * \param stream the audio stream to destroy. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_CreateAudioStream + */ +extern SDL_DECLSPEC void SDLCALL SDL_DestroyAudioStream(SDL_AudioStream *stream); + + +/** + * Convenience function for straightforward audio init for the common case. + * + * If all your app intends to do is provide a single source of PCM audio, this + * function allows you to do all your audio setup in a single call. + * + * This is also intended to be a clean means to migrate apps from SDL2. + * + * This function will open an audio device, create a stream and bind it. + * Unlike other methods of setup, the audio device will be closed when this + * stream is destroyed, so the app can treat the returned SDL_AudioStream as + * the only object needed to manage audio playback. + * + * Also unlike other functions, the audio device begins paused. This is to map + * more closely to SDL2-style behavior, since there is no extra step here to + * bind a stream to begin audio flowing. The audio device should be resumed + * with `SDL_ResumeAudioStreamDevice(stream);` + * + * This function works with both playback and recording devices. + * + * The `spec` parameter represents the app's side of the audio stream. That + * is, for recording audio, this will be the output format, and for playing + * audio, this will be the input format. If spec is NULL, the system will + * choose the format, and the app can use SDL_GetAudioStreamFormat() to obtain + * this information later. + * + * If you don't care about opening a specific audio device, you can (and + * probably _should_), use SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK for playback and + * SDL_AUDIO_DEVICE_DEFAULT_RECORDING for recording. + * + * One can optionally provide a callback function; if NULL, the app is + * expected to queue audio data for playback (or unqueue audio data if + * capturing). Otherwise, the callback will begin to fire once the device is + * unpaused. + * + * Destroying the returned stream with SDL_DestroyAudioStream will also close + * the audio device associated with this stream. + * + * \param devid an audio device to open, or SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK + * or SDL_AUDIO_DEVICE_DEFAULT_RECORDING. + * \param spec the audio stream's data format. Can be NULL. + * \param callback a callback where the app will provide new data for + * playback, or receive new data for recording. Can be NULL, + * in which case the app will need to call + * SDL_PutAudioStreamData or SDL_GetAudioStreamData as + * necessary. + * \param userdata app-controlled pointer passed to callback. Can be NULL. + * Ignored if callback is NULL. + * \returns an audio stream on success, ready to use, or NULL on failure; call + * SDL_GetError() for more information. When done with this stream, + * call SDL_DestroyAudioStream to free resources and close the + * device. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_GetAudioStreamDevice + * \sa SDL_ResumeAudioStreamDevice + */ +extern SDL_DECLSPEC SDL_AudioStream * SDLCALL SDL_OpenAudioDeviceStream(SDL_AudioDeviceID devid, const SDL_AudioSpec *spec, SDL_AudioStreamCallback callback, void *userdata); + +/** + * A callback that fires when data is about to be fed to an audio device. + * + * This is useful for accessing the final mix, perhaps for writing a + * visualizer or applying a final effect to the audio data before playback. + * + * This callback should run as quickly as possible and not block for any + * significant time, as this callback delays submission of data to the audio + * device, which can cause audio playback problems. + * + * The postmix callback _must_ be able to handle any audio data format + * specified in `spec`, which can change between callbacks if the audio device + * changed. However, this only covers frequency and channel count; data is + * always provided here in SDL_AUDIO_F32 format. + * + * The postmix callback runs _after_ logical device gain and audiostream gain + * have been applied, which is to say you can make the output data louder at + * this point than the gain settings would suggest. + * + * \param userdata a pointer provided by the app through + * SDL_SetAudioPostmixCallback, for its own use. + * \param spec the current format of audio that is to be submitted to the + * audio device. + * \param buffer the buffer of audio samples to be submitted. The callback can + * inspect and/or modify this data. + * \param buflen the size of `buffer` in bytes. + * + * \threadsafety This will run from a background thread owned by SDL. The + * application is responsible for locking resources the callback + * touches that need to be protected. + * + * \since This datatype is available since SDL 3.2.0. + * + * \sa SDL_SetAudioPostmixCallback + */ +typedef void (SDLCALL *SDL_AudioPostmixCallback)(void *userdata, const SDL_AudioSpec *spec, float *buffer, int buflen); + +/** + * Set a callback that fires when data is about to be fed to an audio device. + * + * This is useful for accessing the final mix, perhaps for writing a + * visualizer or applying a final effect to the audio data before playback. + * + * The buffer is the final mix of all bound audio streams on an opened device; + * this callback will fire regularly for any device that is both opened and + * unpaused. If there is no new data to mix, either because no streams are + * bound to the device or all the streams are empty, this callback will still + * fire with the entire buffer set to silence. + * + * This callback is allowed to make changes to the data; the contents of the + * buffer after this call is what is ultimately passed along to the hardware. + * + * The callback is always provided the data in float format (values from -1.0f + * to 1.0f), but the number of channels or sample rate may be different than + * the format the app requested when opening the device; SDL might have had to + * manage a conversion behind the scenes, or the playback might have jumped to + * new physical hardware when a system default changed, etc. These details may + * change between calls. Accordingly, the size of the buffer might change + * between calls as well. + * + * This callback can run at any time, and from any thread; if you need to + * serialize access to your app's data, you should provide and use a mutex or + * other synchronization device. + * + * All of this to say: there are specific needs this callback can fulfill, but + * it is not the simplest interface. Apps should generally provide audio in + * their preferred format through an SDL_AudioStream and let SDL handle the + * difference. + * + * This function is extremely time-sensitive; the callback should do the least + * amount of work possible and return as quickly as it can. The longer the + * callback runs, the higher the risk of audio dropouts or other problems. + * + * This function will block until the audio device is in between iterations, + * so any existing callback that might be running will finish before this + * function sets the new callback and returns. + * + * Setting a NULL callback function disables any previously-set callback. + * + * \param devid the ID of an opened audio device. + * \param callback a callback function to be called. Can be NULL. + * \param userdata app-controlled pointer passed to callback. Can be NULL. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioPostmixCallback(SDL_AudioDeviceID devid, SDL_AudioPostmixCallback callback, void *userdata); + + +/** + * Load the audio data of a WAVE file into memory. + * + * Loading a WAVE file requires `src`, `spec`, `audio_buf` and `audio_len` to + * be valid pointers. The entire data portion of the file is then loaded into + * memory and decoded if necessary. + * + * Supported formats are RIFF WAVE files with the formats PCM (8, 16, 24, and + * 32 bits), IEEE Float (32 bits), Microsoft ADPCM and IMA ADPCM (4 bits), and + * A-law and mu-law (8 bits). Other formats are currently unsupported and + * cause an error. + * + * If this function succeeds, the return value is zero and the pointer to the + * audio data allocated by the function is written to `audio_buf` and its + * length in bytes to `audio_len`. The SDL_AudioSpec members `freq`, + * `channels`, and `format` are set to the values of the audio data in the + * buffer. + * + * It's necessary to use SDL_free() to free the audio data returned in + * `audio_buf` when it is no longer used. + * + * Because of the underspecification of the .WAV format, there are many + * problematic files in the wild that cause issues with strict decoders. To + * provide compatibility with these files, this decoder is lenient in regards + * to the truncation of the file, the fact chunk, and the size of the RIFF + * chunk. The hints `SDL_HINT_WAVE_RIFF_CHUNK_SIZE`, + * `SDL_HINT_WAVE_TRUNCATION`, and `SDL_HINT_WAVE_FACT_CHUNK` can be used to + * tune the behavior of the loading process. + * + * Any file that is invalid (due to truncation, corruption, or wrong values in + * the headers), too big, or unsupported causes an error. Additionally, any + * critical I/O error from the data source will terminate the loading process + * with an error. The function returns NULL on error and in all cases (with + * the exception of `src` being NULL), an appropriate error message will be + * set. + * + * It is required that the data source supports seeking. + * + * Example: + * + * ```c + * SDL_LoadWAV_IO(SDL_IOFromFile("sample.wav", "rb"), true, &spec, &buf, &len); + * ``` + * + * Note that the SDL_LoadWAV function does this same thing for you, but in a + * less messy way: + * + * ```c + * SDL_LoadWAV("sample.wav", &spec, &buf, &len); + * ``` + * + * \param src the data source for the WAVE data. + * \param closeio if true, calls SDL_CloseIO() on `src` before returning, even + * in the case of an error. + * \param spec a pointer to an SDL_AudioSpec that will be set to the WAVE + * data's format details on successful return. + * \param audio_buf a pointer filled with the audio data, allocated by the + * function. + * \param audio_len a pointer filled with the length of the audio data buffer + * in bytes. + * \returns true on success. `audio_buf` will be filled with a pointer to an + * allocated buffer containing the audio data, and `audio_len` is + * filled with the length of that audio buffer in bytes. + * + * This function returns false if the .WAV file cannot be opened, + * uses an unknown data format, or is corrupt; call SDL_GetError() + * for more information. + * + * When the application is done with the data returned in + * `audio_buf`, it should call SDL_free() to dispose of it. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_free + * \sa SDL_LoadWAV + */ +extern SDL_DECLSPEC bool SDLCALL SDL_LoadWAV_IO(SDL_IOStream *src, bool closeio, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len); + +/** + * Loads a WAV from a file path. + * + * This is a convenience function that is effectively the same as: + * + * ```c + * SDL_LoadWAV_IO(SDL_IOFromFile(path, "rb"), true, spec, audio_buf, audio_len); + * ``` + * + * \param path the file path of the WAV file to open. + * \param spec a pointer to an SDL_AudioSpec that will be set to the WAVE + * data's format details on successful return. + * \param audio_buf a pointer filled with the audio data, allocated by the + * function. + * \param audio_len a pointer filled with the length of the audio data buffer + * in bytes. + * \returns true on success. `audio_buf` will be filled with a pointer to an + * allocated buffer containing the audio data, and `audio_len` is + * filled with the length of that audio buffer in bytes. + * + * This function returns false if the .WAV file cannot be opened, + * uses an unknown data format, or is corrupt; call SDL_GetError() + * for more information. + * + * When the application is done with the data returned in + * `audio_buf`, it should call SDL_free() to dispose of it. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + * + * \sa SDL_free + * \sa SDL_LoadWAV_IO + */ +extern SDL_DECLSPEC bool SDLCALL SDL_LoadWAV(const char *path, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len); + +/** + * Mix audio data in a specified format. + * + * This takes an audio buffer `src` of `len` bytes of `format` data and mixes + * it into `dst`, performing addition, volume adjustment, and overflow + * clipping. The buffer pointed to by `dst` must also be `len` bytes of + * `format` data. + * + * This is provided for convenience -- you can mix your own audio data. + * + * Do not use this function for mixing together more than two streams of + * sample data. The output from repeated application of this function may be + * distorted by clipping, because there is no accumulator with greater range + * than the input (not to mention this being an inefficient way of doing it). + * + * It is a common misconception that this function is required to write audio + * data to an output stream in an audio callback. While you can do that, + * SDL_MixAudio() is really only needed when you're mixing a single audio + * stream with a volume adjustment. + * + * \param dst the destination for the mixed audio. + * \param src the source audio buffer to be mixed. + * \param format the SDL_AudioFormat structure representing the desired audio + * format. + * \param len the length of the audio buffer in bytes. + * \param volume ranges from 0.0 - 1.0, and should be set to 1.0 for full + * audio volume. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +extern SDL_DECLSPEC bool SDLCALL SDL_MixAudio(Uint8 *dst, const Uint8 *src, SDL_AudioFormat format, Uint32 len, float volume); + +/** + * Convert some audio data of one format to another format. + * + * Please note that this function is for convenience, but should not be used + * to resample audio in blocks, as it will introduce audio artifacts on the + * boundaries. You should only use this function if you are converting audio + * data in its entirety in one call. If you want to convert audio in smaller + * chunks, use an SDL_AudioStream, which is designed for this situation. + * + * Internally, this function creates and destroys an SDL_AudioStream on each + * use, so it's also less efficient than using one directly, if you need to + * convert multiple times. + * + * \param src_spec the format details of the input audio. + * \param src_data the audio data to be converted. + * \param src_len the len of src_data. + * \param dst_spec the format details of the output audio. + * \param dst_data will be filled with a pointer to converted audio data, + * which should be freed with SDL_free(). On error, it will be + * NULL. + * \param dst_len will be filled with the len of dst_data. + * \returns true on success or false on failure; call SDL_GetError() for more + * information. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +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); + +/** + * Get the human readable name of an audio format. + * + * \param format the audio format to query. + * \returns the human readable name of the specified audio format or + * "SDL_AUDIO_UNKNOWN" if the format isn't recognized. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +extern SDL_DECLSPEC const char * SDLCALL SDL_GetAudioFormatName(SDL_AudioFormat format); + +/** + * Get the appropriate memset value for silencing an audio format. + * + * The value returned by this function can be used as the second argument to + * memset (or SDL_memset) to set an audio buffer in a specific format to + * silence. + * + * \param format the audio data format to query. + * \returns a byte value that can be passed to memset. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +extern SDL_DECLSPEC int SDLCALL SDL_GetSilenceValueForFormat(SDL_AudioFormat format); + + +/* Ends C function definitions when using C++ */ +#ifdef __cplusplus +} +#endif +#include + +#endif /* SDL_audio_h_ */ -- cgit v1.2.3