Function ffav_sys::av_buffer_create

pub unsafe extern "C" fn av_buffer_create(
    data: *mut u8, 
    size: c_int, 
    free: Option<unsafe extern "C" fn(opaque: *mut c_void, data: *mut u8)>, 
    opaque: *mut c_void, 
    flags: c_int
) -> *mut AVBufferRef