How to take baked-in B-roll out of a clip without touching its audio or captions
Ask Vizard Agent to remove the B-roll from the clip and keep everything else. Cutting the cutaways out would break the continuous speech, so it detects each cutaway frame from the clip's own layout, replaces those frames with a clean frame of the speaker, re-lays the burnt-in captions over them, and leaves the audio stream exactly as it was.
What do you type into Vizard Agent?
Say which inserts go and that the rest is fixed. "Remove the B-roll" can mean cutting it out, which shortens the clip and jumps the speech, or covering it, which keeps every word in place. Saying the audio and captions must not change rules out the first.
Remove the B-roll from the "don't neglect high performers" clip. There are still slight flashes of the B-roll in it. Keep the audio, the headline and the captions exactly as they are.
What does Vizard Agent actually do?
It turns "is this frame a cutaway?" into a measurement it can run on every frame. The clip's own layout gives the test: a strip of the frame that is dark on the webinar view and bright on a cutaway. In the session behind this article it:
- Mapped the clip at two frames a second on a timecoded contact sheet to see where the cutaways sat.
- Built a per-frame detector from the brightness of a dark band under the webinar view, and recalibrated its threshold after the first setting flagged every frame.
- Found two runs of cutaway frames and replaced them with a held clean frame of the speaker.
- Lifted the burnt-in caption text out of the cutaway frames and laid it back on top, and copied the audio stream unchanged.
- After the user saw a flash, ran the same detector on its own output, found one frame surviving at the start of each run, padded both runs, re-scanned all 480 frames clean, and checked the audio hash.
When does this not work well?
When the speaker is never on screen during the cutaway. A held frame works for a few seconds, but a long insert over continuous speech turns into a frozen picture with a moving voice, and you are better off with a different shot of the speaker or a graphic.
Common questions
Why are there still flashes after removing B-roll? A frame or two survived. Vizard Agent checks every frame for them.
Will the speech stay in sync? Yes. Vizard Agent replaces frames and leaves the audio as it was.
What happens to the captions? Vizard Agent lifts them from the cutaway frames and puts them back.