Gpx and image location difference

Imagery, data, and integrations
1

Hey,

I’m looking for an explanation of a strange issue:

I’ve made a contribution using GoPro Max. If I upload the sequence in the original .360 format, all good with locations and imagery. I wanted to put a nadir patch on the imagery, so I exported GPS data, converted the file to .mp4, added the nadir logo, and uploaded .mp4 with along with previously exported .gpx.

With this setup I see the correct locations on the map, but the photos show a slightly earlier moment than the should. It is negligible or zero in the beginning, but gets significant with the imagery captured close the end of sequence.

Showing the last photos of each sequence as an example below:

Correct (uploaded as .360): Mapillary

Incorrect (uploaded as .mp4 and .gpx): Mapillary

The locations are practically the same but the photos are different, and the last few dozen metres are not shown anywhere in the latter sequence.
image

Can anyone help me explaining this phenomenon?

Tool used for .gpx export: Telemetry Lite for GoPro
Tool used for .mp4 edit: Wondershare Filmora
I checked, starting and ending timestamps of video and .gpx match.

2

Hi @mibo - could you share the files you were using (.360, .mp4, and .gpx) for us to take a look?

In general for GPX export I would recommend exiftool, this is what mapillary uses under the hood as well. To extract .gpx from the .360 file you would run a command like:

exiftool -p /usr/local/bin/gpx.fmt -ee3 -api largefilesupport=1 "sample.360" > out.gpx

You can get the refenced gpx.fmt file at https://raw.githubusercontent.com/exiftool/exiftool/master/fmt_files/gpx.fmt

Also, the edited video file is visually lower quality (more compression artifacts making it harder to see detail), so I would encourage you to either upload and use the original .360, or choose higher quality compression settings in your video editor.