SlackBuildsOrg/multimedia/xjadeo

Xjadeo is a software video player that displays a video-clip in sync
with an external time source (MTC, LTC, JACK-transport).

Xjadeo is useful in soundtrack composition, video monitoring or any
task that requires to synchronizing movie frames with audio events.

Xjadeo supports a multitude of video file formats, display libraries
and sync sources. It includes an optional GUI called qjadeo that
provides setup options, file history, video import/transcoding and
control of Xjadeo's run-time parameters.

Optional dependencies are portmidi, lash, jack, and imlib2.