This should be the last function you call in SDL_mixer, after freeing all other resources and closing all audio devices. This will unload any shared libraries it is using for various codecs.
After this call, a call to Mix_Init(0) will return 0 (no codecs loaded).
You can safely call Mix_Init() to reload various codec support after this call.
Unlike other SDL satellite libraries, calls to Mix_Init do not stack; a single call to Mix_Quit() will deinitialize everything and does not have to be paired with a matching Mix_Init call. For that reason, it's considered best practices to have a single Mix_Init and Mix_Quit call in your program. While this isn't required, be aware of the risks of deviating from that behavior.
This function is available since SDL_mixer 2.0.0.