How to sync multiple cameras and an audio recorder by sound, without timecode

What you need

1. Record with sound on every camera

Waveform sync needs every camera to hear the room, so leave each camera's microphone on, even a scratch mic. A clap or saying “action” at the start gives every microphone the same sharp sound to match.

2. Copy each card into its own folder

One folder per camera or recorder, for example Sony A, Sony B, Zoom. Copy the whole card; how it's organised inside doesn't matter. Two cameras need two folders.

3. Add the folders to ActionCheese Sync

Open ActionCheese Sync and use Add folder… for each one. You can also add a Premiere timeline exported with File › Export › Final Cut Pro XML, one camera or recorder per track, or mix both.

4. Choose where to save, and press Sync

Pick a file under Output XML and press Sync. It decodes the audio, matches every clip against the others, refines each match to well under a frame, and solves the whole shoot at once. Long recorder takes are checked for clock drift and corrected with a tiny speed change to the audio only.

5. Check the result

The Timeline tab shows your footage as imported and as synced. Clips that couldn't be matched sit on their own track in red, placed by their recording time where possible. The Log lists what moved, by how much, and any drift in ppm.

6. Import into your editor

In Premiere Pro, File › Import and pick the XML. In DaVinci Resolve, File › Import › Timeline. The synced sequence is named after your input with _synced added, so it sits beside your original.

Questions

Do I need timecode to sync multiple cameras?

No. Sync by sound works from the audio every camera recorded, so cameras and recorders with unrelated clocks still line up.

How do I fix audio that slowly goes out of sync on a long recording?

That's clock drift between the recorder and the camera. ActionCheese Sync measures it across the clip and writes a small speed correction to the recorder's audio; the picture is never resampled.

What if a camera's clip has no usable sound?

Once any clip from that camera has matched, Sync knows that camera's clock and places its other clips by their recording time. Clips it can't place go on their own track, marked in red.

Can I run it from Terminal?

Yes. The app contains the same engine as a command-line tool, for batch jobs and scripts. See the command-line help.