Data synchronization techniques

[Spaghetti]

I'm having the hardest time synchronizing Harry's Lap Timer data with video. The documentation suggest to locate the point when the g-force gauge starts moving as a reference point and match the vehicle first move in the video, but the problem is that HLT doesn't log until a certain speed is reached to avoid recording pointless pit data.

Are there other ways to synchronize data with video? Any youtube tutorial?

[Weston@HPTuners]

With any data system that provides GPS data, I usually start with the vehicle's indicated position on the track map plot... You should be able to get the video and data sync close based on that, especially if your data system used a precisely-defined start/finish point and that line on the track is visible in your video.

To further fine-tune the synchronization from there, or if you just had a system where no GPS data was available to begin with, it's usually best to look for moments where you can see or hear an event in the video that would correspond with a big change in the data.

A few ideas:

- Heavy braking is often evident in the video by seeing the front suspension compress, and the data would show it in the g-force, vehicle speed, and engine RPM (if available)

- Initial turn-in for a corner would be evident in the video, and the data would show a corresponding change in lateral g-force. S-curves, slaloms, or tire scrubbing movements are especially helpful because you can match the back-and-forth motion.

- Gear shifts should be evident by listening to the audio, so you could stop the preview at that moment, and then sync the data until you see the corresponding change in engine RPM or indicated gear position (depending on what your data provides).

- If your vehicle comes to a stop at any point that is covered by the data and video (ie standing start, pit stop, red flag, or after the race is over), you could sync the video of you coming to a stop with the speed data going to zero. The same approach can also be used if you ever start moving from being at a stop.

[Spaghetti]

Thanks for the help. To add to my problem the start was from the pit, so it wasn't clear where the matching GPS data was by looking at the pointer on the track map. I looked at the first acceleration after entering the track and tried to match video/speed indicator. It's a bit off, around a second I would say: https://youtu.be/8doCX42-Lsc

[k24556]

Thanks for the help. To add to my problem the start was from the pit, so it wasn't clear where the matching GPS data was by looking at the pointer on the track map. I looked at the first acceleration after entering the track and tried to match video/speed indicator. It's a bit off, around a second I would say: https://youtu.be/8doCX42-Lsc

What I do is set my phone to a stopwatch mode and start timing from the time the video starts until I see 10mph show up on the speedo graphic. the when it hits 10 mph, you know data has turned on. That usually gets me within a second. Then I write that number down and fine tune from there. I have the hardest time adding and subtracting small increments to finally dial it in, because it seems I subtract time when I should add.