Change the gain of an audio device.
Defined in <SDL3/SDL_audio.h>
bool SDL_SetAudioDeviceGain(SDL_AudioDeviceID devid, float gain);
SDL_AudioDeviceID | devid | the audio device on which to change gain. |
float | gain | the gain. 1.0f is no change, 0.0f is silence. |
(bool) Returns true on success or false on failure; call SDL_GetError() for more information.
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.
It is safe to call this function from any thread, as it holds a stream-specific mutex while running.
This function is available since SDL 3.0.0.