Python has gzip libraries so I rewrote the script to make less work for the end user. No need to unzip the source LapTimer file. Now all you have to do is point it at the file, specify the correction factor, and it does all the work and returns a corrected and gzipped LapTimer file. Here's the code ...

Oh yeah, in case anyone wants the code for some reason, here it is. Replace the file name with the file in the same directory as the script, and "0.96" with your correction factor. After this is done, rename the "corrected_speed.xml" file to the original hlptrz file name, and the...

I was able to apply correction retroactively to the OBD speed by unzipping the hlptrz file, and writing a python script that went through and multiplied every OBD speed by .96 and then saved it as a new XML file. Thanks for using standard file formats, Harry! Here's the updated vid. I still think so...

Thanks again.

Thanks. It looks like the correction factor isn't retroactive. I just changed it to .96 and overlaid the video again, but the OBD displayed MPH were still too high. Is there anyway to retroactively fix the lap file to have the OBD values reduced by 4%? I don't see any kind of global correction varia...

I have an XGPS150, but the speeds it's reporting seem to be off at some times, and out of sync at others. I've uploaded two videos to youtube, one with GPS speed, and the other without (I guess it got the speed from OBD?). Neither of them are as accurate as they should be. The speed of the car is vi...

You are correct Harry. I was able to get everything synced up properly when I stopped worrying about the sync point in the newly overlaid video. Thanks.

I have a clip that was recorded outside of HLT I'm trying to overlay data onto. I've done this before without too much hassle. Set the end time of the lap, overlay it, if there's any timing issues, tweak the end time of the lap and overlay again. Repeat until everything lines up perfectly. The probl...

This redesign looks EXCELLENT.

To be able to quickly learn which lines are the fastest, it would be awesome if you could take all of the videos and track data from a weekend, and stitch together the fastest sectors. You'd then be able to watch the fastest way around the track. You'd also be able to see what your theoretical faste...