Virb Edit not reading TrackPointExtension speed

Hi,

I export GoPro GPS data to use it in Virb Edit. Virb does a great job in general, but speeds are between mostly wrong and completely wrong. Calculated speeds only seem decent if the

trkpt frequency is close to 1 second (it's still lower than the real speed), and "recorded" speeds are completely wrong, even though I'm following Garmin's TrackPointExtension schema: https://www8.garmin.com/xmlschemas/TrackPointExtensionv2.xsd

My trkpts look like this

<trkpt lat="43.25934222222222" lon="13.505879233333333">
    <ele>146.82833333333332</ele>
    <time>2020-03-01T14:36:40.515Z</time>
    <extensions>
        <gpxtpx:TrackPointExtension>
            <gpxtpx:speed>0.23555555555555557</gpxtpx:speed>
        </gpxtpx:TrackPointExtension>
    </extensions>
</trkpt>

And the extension is declared at the top:

<gpx xmlns="http://www.topografix.com/GPX/1/1" 
  xmlns:gpxtpx="http://www.garmin.com/xmlschemas/TrackPointExtension/v2" version="1.1" creator="https://github.com/juanirache/gopro-telemetry">

With high frequencies (18Hz) the calculated speeds are between 0.1 and 0.4 km/h instead of the real ~90 km/h. If I convert the file to 1 sample per second calculated speeds get closer to reality, about 75 km/h.

The "recorded speeds" are always absolutely wrong, and they do not change even if I delete the <extensions> section of each trkpt. So Virb Edit is not reading those data at all, just making up some values based on I don't know what.

On top is the "recorded" 3D speed, then calculated 3d and calculated 2d. As you can see, there is absolutely no relation between the "recorded" data and reality, but the fact is the speed recorded in the GPX file is correct.

Does anyone know what's going on?

Thank you

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0 Kajuna over 4 years ago

I find it fascinating that Garmin has staff available to moderate the posts, but no one to reply to them. Is there any other channel that I should submit this to?

0 seilogramp over 4 years ago in reply to Kajuna

Most of the moderators are volunteers, not Garmin staff. This particular forum does not get a lot of activity and I'm afraid I don't have the expertise to help you. You can try submitting a case via the Garmin Support Center https://support.garmin.com

0 Kajuna over 4 years ago in reply to seilogramp

Thanks. If they're volunteers, my respects for them. Will use the support center.

0 Kajuna over 4 years ago

Update:

- Someone helped me find out that Virb DOES read some of the GPX extensions. Particularly, acceleration seems to work fine (although you have to include every value twice, for some odd reason): www8.garmin.com/.../AccelerationExtensionv1.xsd

- I tried implementing the Activity Extensions and using the Speed value from there, but Virb keeps showing absurd values. Tried both v2 https://www8.garmin.com/xmlschemas/ActivityExtensionv2.xsd and v1 www8.garmin.com/.../ActivityExtensionv1.xsd

0 JACOBBAX over 4 years ago in reply to Kajuna

When I look at the gpx files my garmin GPSMap 78s creates, I see no speed extensions.

When I open it in Basecamp I see a speed that can be right, so I think Basecamp and Virb edit calculates it from the position and time extensions. Probably the gpx files from your gopro are different from what VirbEdit wil see.

This is what a 78s trackpoint looks like in Wordpad.

><trkpt lat="54.7116667964" lon="-0.5185030214">

<gpxtpx:atemp>22.5</gpxtpx:atemp>

</gpxtpx:TrackPointExtension>

</extensions>

</trkpt>

This is the tracklog point from a GPSMap 60CSx

Maybe you can try to remove the extensions parts out of the tracklog.

everything between </time> and </trkpt>

0 Kajuna over 4 years ago in reply to JACOBBAX

@JACOBBAX

Thanks for the suggestions.

I create the GPX files myself with the GoPro data. The problem is the speed calculated by Virb Edit from the standard GPX files is WRONG. That's why I'm trying to use extensions to store the correct speed value.

Could you paste two consecutive trkpt samples from your file? Virb Edit (at least the Windows version) calculates a different speed depending on the frequency of the data, so I'm wondering which frequency their own hardware uses.

0 JACOBBAX over 4 years ago in reply to Kajuna

</trkseg>

This is from the GPSMap 60CSx should be somewhere around 52km/h

0 JACOBBAX over 4 years ago in reply to JACOBBAX

</trkseg>

This one is from a GPSMap 78s should be 74 km/h

Hope you can do something with this.

0 Kajuna over 4 years ago in reply to JACOBBAX

Thanks. The frequency seems to be around 10Hz, which is much higher than what gives me good speed results in Virb Edit. I cannot test such short samples, but do they produce reasonable speeds in Virb Edit for you? Or do you just use them in Basecamp? I seem to remember basecamp did compute correct speeds when I checked. If you want to send the full samples privately, my email is [email protected]. However, these seem pretty standard files, so I don't expect different results form what I've tested in the past.