How to sync a separate audio recording to your camera footage
Upload every camera and the separate audio file. Vizard Agent cross-correlates the recorder against each camera's own scratch track to find the exact offset, then checks whether the clocks drifted apart across the recording, which is the failure that ruins long dual-system edits.
What do you type into Vizard Agent?
Say what the pieces are and what the finished thing should be. Vizard Agent works out the sync itself, so the useful instruction is about the edit: how tight, where it should end, and which camera to favour. Upload the camera audio too, even if you won't use it, because the sync is measured against it.
Prompt
What does Vizard Agent actually do?
Finding the offset is the easy part. Two devices started at the same moment still run at slightly different rates, so an edit that is synced at the top can be a frame or two out by the end. Vizard Agent measures the offset, then checks that it holds for the whole recording. In the session behind this article it:
- Checked the format and length of both cameras and the audio, extracted the camera audio, and cross-correlated it against the recorder to find the offset.
- Compared the two angles over time and checked for clock drift across the 35-minute interview.
- Transcribed the master audio, worked out who was on which camera and who was speaking, and found the exact word timings at every splice point.
- Measured the dialogue loudness and the noise floor in the pauses, then built the paper edit and the camera-switch plan and tested the punch-in framings.
- Delivered a 3240x2160, 23.976fps HEVC master running 2094 seconds, a 720p proxy because the master was over seven gigabytes, and a timecoded list of every cut. Three cuts were put back on request.
When does this not work well?
The failure modes are about the recordings rather than the edit. With no camera audio at all there's nothing to correlate against, and recordings that don't overlap can't be aligned. Severe drift on long takes needs resampling, and cameras that stop at different times leave you to decide the ending. Vizard Agent reports what it can't align rather than nudging it.
Common questions
Do I need a clapperboard? It helps but is not required. Vizard Agent syncs from the waveforms themselves.
What is clock drift? Two devices running at very slightly different rates. Vizard Agent checks for it rather than assuming.
What about the names on screen? Vizard Agent won't guess them. When public sources disagreed on the spellings, it left the lower thirds off and asked.