It was never actually used since it was introduced as part of the commit introducing support for instant rate Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7077>
It was never actually used since it was introduced as part of the commit introducing support for instant rate Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7077>