(This is the legacy documentation for SDL2, the previous stable version; SDL3 is the current stable version.)

SDL_GetNumAudioDevices

Get the number of built-in audio devices.

Header File

Syntax

int SDL_GetNumAudioDevices(int iscapture);

Function Parameters

int

iscapture

zero to request playback devices, non-zero to request recording devices.

Return Value

(int) Returns the number of available devices exposed by the current driver or -1 if an explicit list of devices can't be determined. A return value of -1 does not necessarily mean an error condition.

Remarks

This function is only valid after successfully initializing the audio subsystem.

Note that audio capture support is not implemented as of SDL 2.0.4, so the iscapture parameter is for future expansion and should always be zero for now.

This function will return -1 if an explicit list of devices can't be determined. Returning -1 is not an error. For example, if SDL is set up to talk to a remote audio server, it can't list every one available on the Internet, but it will still allow a specific host to be specified in SDL_OpenAudioDevice().

In many common cases, when this function returns a value <= 0, it can still successfully open the default device (NULL for first argument of SDL_OpenAudioDevice()).

This function may trigger a complete redetect of available hardware. It should not be called for each iteration of a loop, but rather once at the start of a loop:

// Don't do this:
for (int i = 0; i < SDL_GetNumAudioDevices(0); i++)

// do this instead:
const int count = SDL_GetNumAudioDevices(0);
for (int i = 0; i < count; ++i) { do_something_here(); }

Version

This function is available since SDL 2.0.0.