You can add black filler on either the A-side or the B-side of a transition while maintaining the overall duration of the track and the sync relationships. The system adds a black segment to fill the duration of the trimmed frames.
The system adds a black segment without changing the duration of the
sequence.
After you add black filler to a video track, you can replace the filler with footage by performing a replace edit. For more information, see
Performing a Replace Edit.