pub unsafe extern "C" fn gst_clock_add_observation_unapplied(
clock: *mut GstClock,
slave: GstClockTime,
master: GstClockTime,
r_squared: *mut c_double,
internal: *mut GstClockTime,
external: *mut GstClockTime,
rate_num: *mut GstClockTime,
rate_denom: *mut GstClockTime,
) -> gboolean