Action cam suggestions for Mapillary (and OSC)?

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I would like to start contributing to Mapillary by uploading the routes I cycle and was thinking of treating myself to an action camera an the new year. free netflix tech news

What are peoples thoughts on using these cams instead of the mobile apps for data. Is it easy to convert the video to images outside of the app? I’d like if possible to do it via command line rather than a gui.

Any recommendations for a camera, I had been thinking of the new GoPro Hero Black 7 as I think the stabilization might be useful when it comes to reviewing the data

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My original setup was a USB webcam that I accessed with uvccapture, then inserted the GPS EXIF data from an attached receiver. I then used mapillary tools to add all the info required for upload. This all done with Linux command line tools.

The GoPro you mentioned appears to have GPS/gpx capabilities. If it doesn’t insert that as EXIF data then mapillary tools can use the gpx file. It all works quite well and has many options.

I currently use a BlackVue dashcam that records as mp4’s (movies) with encoded GPS data. I also use the mapillary tools for that. About the only concern I have with mp4 to jpg conversion is the quality loss. If the GoPro can create mjpeg’s I’d suggest you go with that.

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Mapillary have some Python scripts at GitHub - mapillary/mapillary_tools: Command line tools for processing and uploading Mapillary imagery for both geotagging,managing video and other processing. But they have a steep learning curve. There is also the desktop uploader at Mapillary Uploader for Desktop - I don’t know if it helps with processing or it is purely uploading.

Many action cameras will also take timelap pictures, e.g. a picture every 2 seconds. They are the easiest if they have GPS, then the images are ready to upload.

Personally I mainly use a Xiaomi MiSphere, a 360 degree camera, on a selfie stick put into my backpack. It captures everything and my body removes most shaking. It requires postprocessing in an Android app to get a good result, through.

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I am not happy with my Gopro Hero 7 Black. The remote is unreliable, the camera crashes. It even seldomly forgets to write GPS exif.

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Unless you want video for purposes beyond Mapillary, the easiest method with a GoPro is to take photos at 1-second intervals rather than videos.

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Better 1/2 second interval.

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mapillary tools uses ffmpeg to convert the video to images.eg

ffmpeg -i movie.mp4 -loglevel quiet -vf fps=1/0.5 -qscale 1 -nostdin frames_%06d.jpg

This doesnt handle the GPS data though.

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depending on your budget, you could go for:

  • a 360 action cam (expensive, only Fusion has decent gps capabilities of its own),
  • a normal action cam - gopro has mixed feedback on here, old garmins (virb elite) seem ok and have gps, virb x/xs are not very suitable for fast changing exposure from what I’ve seen, and ultra30 seems ok - but there is the garmin tax on all of them,
  • a cheap action cam from aliexpress/ebay - might not get gps so will have to run a separate gps tracker; will need to check if software supports timelapse (if you want to upload through the web uploader)
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