Function sdl2_sys::SDL_MixAudio

pub unsafe extern "C" fn SDL_MixAudio(
    dst: *mut Uint8, 
    src: *const Uint8, 
    len: Uint32, 
    volume: c_int
)

This takes two audio buffers of the playing audio format and mixes them, performing addition, volume adjustment, and overflow clipping. The volume ranges from 0 - 128, and should be set to ::SDL_MIX_MAXVOLUME for full audio volume. Note this does not change hardware volume. This is provided for convenience -- you can mix your own audio data.