Export GPX from Gopro video not always efficient VS telemetry extractor

[Moshe81]

Hi,
I am finding that for some videos the GPX file that is being extract is not formed in a good manner.
So I thought its something about the Video file itself so I checked it with the alternative way to generate GPX file from MP4 video.
I used this free online tool : https://goprotelemetryextractor.com/free/#
and I found that for the same video the exiftool generate a GPX with lots of jumps which are noise while the online tool generate a good GPX file.
 
I am using this command in order to export all my Motorcycle video to GPX files.

exiftool.exe -p gpx.fmt -ee3 1280_GX011738.MP4 > 1738.gpx

I took the fmt file from the github page : https://github.com/exiftool/exiftool/blob/master/fmt_files/gpx.fmt  the version from Sept-22 2021
I am using the latest exiftool 12.32
Video was capture using Gopro 9 - but for some videos the exiftool is doing well and for some it doesn't.

I am attaching the 2 GPX files one from the exiftool and the other from the online tool.
I hope to get an advice how I can make the extraction to be valid like the online tool.
I can not attached the video as it too big, but if it will be require I can upload it to google drive or something
Thanks
Moshe

[Phil Harvey]

The problem is that the GoPro doesn't store a timestamp for each GPS fix, so the -p option doesn't extract all of the fixes.  Read here for more details.

- Phil

[Moshe81]

Thanks Phil.
Yes I saw this post while I tried to search for solution.
Actually it is not that bad as most of the videos its working ok, I believe its just the first video in the sequence where the camera still didn't get all the data from the satellite is where the issues are.
So for these videos I will still use the online telemetry tool.
I am running the exief tool on my HDD where it extract the GPX from all my videos (using powershell script) - it makes it very easy to find a location from the GPX and then to check how it looks from video.

Thanks
Moshe