Function gst_fd_allocator_alloc_full 

pub unsafe extern "C" fn gst_fd_allocator_alloc_full(
    allocator: *mut GstAllocator,
    fd: c_int,
    maxsize: size_t,
    offset: size_t,
    size: size_t,
    flags: GstFdMemoryFlags,
) -> *mut GstMemory

Available on crate feature v1_28 only.