A little question about a dashboard camcorder

belladaisy2018 · 2018-04-03T15:48:04.000Z

Is anyone using a dashboard camcorder to collecting information that can be used to edit Openstreetmap? If you are what camcorder are you using and how well does it work?

n76 · 2018-04-03T18:22:06.000Z

I installed a Viofo A119s V2 dash cam with GPS mount in my car for other reasons and have found it a useful addition to my mapping.

Upsides:
It is always on so even if I am not planning on mapping on a trip I can still go back and review the videos if I notice something during that trip that ought to be mapped.

While it does not pick up everything, it picks up items that I haven’t bothered to map in the past (bus stops, etc.). Driving through a small town I am more likely to notice and map gas stations and other businesses. Using tools like OsmTracker that was not feasible to do while driving.

Downsides:

Getting the GPX tracks from it requires a bit of futzing (I am on a Mac and the best apps for using that data are Windows based).

Field of view is a bit narrow, so I can’t get all the store signs I’d like.

Street signs, etc. can be a bit too low resolution to easily read.

Support for editing maps using video is not as well developed as I’d like. I end up fast forwarding through my video clips looking for things that could be mapped. Then I use the lat/lon display I have enabled on the video to get to that location in JOSM to add the feature. This is slower and more tedious than I’d like. If the road alignment looks reasonably correct based on satellite imagery and previously uploaded tracks I don’t bother extracting the GPX from the video as that is a bit of a hassle for me.

It would be really nice if JOSM could directly import the GPX from the video files and show you image from any location in the track. Apparently there was once a plug-in that attempted that but it seems to be old and unsupported. No doubt a real effort to bring that up to date as a it seems that there is no real standard or documentation for how dash cams record GPS data.

muralito · 2018-04-03T19:32:26.000Z

See https://www.openstreetcam.org/

n76 · 2018-04-03T19:55:55.000Z

muralito:

See https://www.openstreetcam.org/

That is a project sponsored by Telenav with the goal of producing a body of images and tracks with licensing compatible with OSM, basically a more open version of Mapillary. A laudable goal.

But I couldn’t get it to work correctly on my phone. Possibly because my phone was old and slow but it seemed that even if my raw tracks were shown on the correct road most of the time when I uploaded them to OpenStreetCam their processing moved them to a parallel road.

But OpenStreetCam, at least last I looked, needed you to run their app on your phone. That is a bit different than having a dedicated dash cam mounted on your windshield that runs whenever you start your car. Maybe I am misinterpreting when the original question was, but I thought the question was about dash cams, not cell phone apps.

and1969 · 2018-04-28T19:31:02.000Z

Hi,

I have two Nextbase 402G dashcams, which record GPS encoded MOV files, and use the Russian software Datakam Player (also known as Registrator Viewer) to export GPX files from the videos. The software provided by Nextbase crashed on my PC and I am not sure whether that has a GPX export option. The Datakam Download Website (in Russian) is here: https://datakam.ru/download/. The downloads are in the first section of links (“DATAKAM PLAYER для Windows/Mac”). As I have Windows 10 I downloaded version 6. They also do a Mac version.

The GPX files generated by this software contain coordinates at one second intervals and they seem quite accurate. Also they upload to OSM without any problem.

I am unsure how actively maintained the software is. It displays the GPS trace on various maps including OSM, Google and Yandex, but the licence keys for some of these have expired. Despite which, it still seems to work. It might be expedient to keep a copy of the zip install file, if the software is useful, in case you replace your computer.

n76 · 2018-04-28T20:09:57.000Z

On the topic of getting GPX files out of a dashcam video, like and1969 I have found a way for extracting GPX data from my Viofo A119s dash cam videos. It is a Python script called nvtk_mp42gpx.py written by a Sergei Franco who apparently is in New Zealand based on his email address domain.

I haven’t actually uploaded any of the extracted GPX files to OSM but I have used them as a layer in JOSM and they also load fine in some other mapping software I have.

It does not, however, break the movie into a sequence of geo-tagged photos. OsmTracker, for example, creates a GPX file that has some sort of photo waypoints that show up in JOSM. Makes it associate the photo with the location as the icon for the photo is at the location. Just click on the icon and the photo comes up. Since this script does not do that, it makes editing using the dashcam video less useful than it might otherwise be.

Hmmm. Looking at the GPX file that gets created from my by dashcam by nvtk_mp42gpx.py I see time tags for each position. All at 1 second intervals. If I recall correctly, I can get a JPG image for any given time from a video file using ffmpeg. I think I just added a little item to my “to do” list: Write a script that takes the mp4 file from my Viofo A119s and build a directory containing a OsmTracker style GPX file with associated geo-referenced photos that will open in JOSM. Thanks for the idea! Now I just have to make the time to do some scripting.

n76 · 2018-05-19T17:58:56.000Z

As a follow up, I did write a script to create a set of geo referenced frames/images from the MP4 files created by my Viofo A119S v2 dash cam.

It does help in using the dash cam while editing in JOSM. I wrote about it on my blog at http://retiredtechie.fitchfamily.org/2018/05/13/dashcam-openstreetmap-mapping/ if you are interested.

And I’ve now come across some information that OpenStreetCam has upload scripts that you can use to submit geo referenced images without having to run their app on your phone. I guess the next thing to look into will be submitting stuff from my dash cam to that project.