This tutorial explains how to manually set or fine-tune the synchronisation between a video file and your session data. Use it when:
- A video appears with the red text “Not synchronised” on the Videos screen (automatic synchronisation wasn’t possible), or
- A video is already linked, but the audio/video doesn’t quite line up with the graphs and you want to fine-tune it.
If you haven’t imported the video into your session yet, start with the video import tutorial first. If your video was recorded using the GoPro remote control feature, see the dedicated GoPro-remote tutorial instead — sync points make linking a one-tap operation in that case.
Step 1: Open the video in the Analysis screen
Tap the video thumbnail in the Videos screen to open the Analysis screen.
Step 2: Enter synchronisation mode
Tap the chain-link button to enter synchronisation mode.
Step 3: Find the rough sync point (unlocked)
If the video is not yet linked, synchronisation starts in the unlocked state — the video position and the graph position can be moved independently. If the video is already linked, tap the lock button to unlock the synchronisation if you need to change it by a large amount.
Step 4: Lock and fine-tune
Tap the lock button to lock the synchronisation. The video and graph positions now move in unison, and the video file is linked to the session.
Use the −50 ms and +50 ms buttons to nudge the video into perfect alignment. Pick a sharp, easily identifiable moment and step the offset until video and data line up.
Step 5: Exit synchronisation mode
Tap the Done button to save the synchronisation and leave synchronisation mode.
Tips
- Chapter files. For multi-file recordings, you only need to synchronise the first chapter. RaceChrono links GoPro chapters automatically; for other cameras, use Link after… on each subsequent chapter.
- Resumed sessions. If you resumed the session during recording, make sure the correct Session start or Session resume # entry is selected before syncing — the video belongs to one specific start.