How to cover a re-recorded line with b-roll so the lips do not give it away
Ask Vizard Agent to cut away over the replaced lines rather than lip-syncing them. It places b-roll across exactly the seconds where the new audio runs, then pulls frames from the render to confirm the cover starts before the first replaced word and ends after the last. Wherever your mouth is still visible saying something else, it widens the cutaway.
What do you type into Vizard Agent?
Ask Vizard Agent for cover rather than for correction. The instruction that actually matters is that the picture must leave your face for the whole of those seconds, and that Vizard Agent should go back and confirm it did rather than assuming the placement worked.
Prompt
What does Vizard Agent actually do?
A cutaway placed from the timings usually looks right and is often a few frames short at one end, which is exactly where a viewer's eye lands as the picture changes. Vizard Agent treats placement as unproven until frames from the render confirm it, and matches the level of the cloned lines so the ear doesn't give them away either. In the session behind this article it:
- Transcribed the original talking-head edit with word-level timings and assembled the corrected speech track from the clone of the user's own voice.
- Level-matched the new lines to the user's natural speech and checked the joins so no level jump gave them away.
- Sourced b-roll to suit what each replaced line was about and laid the cutaways across those passages.
- Rendered, pulled review frames and verified that the b-roll fully covered each re-voiced line.
- Widened the cutaways where the cover fell short, then re-rendered and tightened the transitions at the joins, so the cutaways were adjusted twice after going on.
When does this not work well?
Cutting away is not always available. If the shot is the point, or the replaced passage runs for a long stretch, covering it turns into hiding the speaker for a chunk of the video, which viewers read as an edit even without knowing why. Back-to-back corrections merge into one long escape, and very short clips leave no room for a cutaway.
Common questions
Why not just lip-sync it? You can, and Vizard Agent will. Cutaways are cheaper and safer.
What if I have no b-roll? Vizard Agent can find or generate it. Say which you prefer.
Why does it fail at the end and not the start? Because a cutaway is usually cued to the first word, not the last.