Blackvue DR900S-1CH dashcam

With such a dashcam gone is the time when we could not catch or read something.
Even the lateral milestones on the highway are visible.
I guess we have a picture every 5 meters, even at high speed.
I surely need a polarizing filter for it. But even without that I find the pictures a bit too dark. This might be caused by the black spots on my car window above the rear mirror.

My first dashcam upload test had not appeared yet on the map after several days, so for my sunday expedition I used my Gopro Hero Black 7 as a backup. It had some problems with the SD-card, so I was happy to have the dashcam as a backup.

There are several gaps in the sequences. I did not investigate them all.

This gap is OK, The dashcam suddenly changed its location by several meters.

But this one is not. Mapillary has lost several meters which were on the dashcam.

But here my dashcam makes a translation of several tens of meters. I can say many bad things about my Hero7, but that has not happened with my action cam yet.

So should I continue wasting disk space with a backup action cam ?

I have also the Blackvue now. The first uploads took like 5 days to apear in my account. Have not maped that moutch yet. Some difficulty to sellect what to upload or not.

Today 20 of 157 files were refused because they contained no gpx data. I did not do any tunnel.

Starting the unit from cold needs GPS sync up time. I have found in some cases that a wait of 2-3 minutes is needed and if the vehicle is moving during the sync process it can take far longer. I have lost 10-15 minutes in the past when my initial route was in deep forest. Use the solid blue LED indicator to check lock status.

Starting the unit warm (eg warm day only being off for 30 minutes) takes far less time.

This BTW is why I don’t use video upload. I just leave the unit running all day then select only geo-referenced images after process only.

To check GPS is locked by viewing a video, the speed showing a number instead of —.

Yes, the problem was in the forest, even though the leafs are dry. That is really a shame for a supposed state of the art dashcam. It does not even show the correct side of the road.
I’ll make electrical contact as soon as I get in the car.

I won’t make a habit of it, but I uploaded a nightly video.
It shows the Scheldelaan in Antwerp, the chemical street.
The lights are nice to see, and it also gives night only information.
I am happy with the result.

I also was the first to mapillarize the Liefkenshoektunnel from North to South, the entrance and exit at least.

And I don’t know why, I don’t know how but I captured the Kennedytunnel.

Hi @filipc,
i was looking your pictures with dr900s and i’m jealous :smiley:

You don’t have time lapse between gps and picture.

i bought https://help.mapillary.com/hc/en-us/articles/360029012811-BlackVue-Mapillary-Dashcam-

i use “mapillary tools” (https://github.com/mapillary/mapillary_tools#command-specifications BlackVue, Direct Upload (Recommended) without specials issues but i have time lapse between picture and gps.

For example, on the picture it’s a crossroad (https://www.mapillary.com/app/?lat=44.858302301111166&lng=-0.6804426537908057&z=17&tab=uploads&pKey=moyWOGqXmBVGdGJBxZcQzW&focus=photo) but on map ther’s a 10 pictures différence.

Mapillary told me be email it’s a known bug but you didn’t have it ? Do you have a special way to do your video upload on mapillary server ?

Thanks

The


can only upload videos from that Blackvue dashcam.

So you are lucky, use the desktop uploader.

i can’t, i’m on linux and mapillary uploader for desktop isn’t working.

you think with mapillary uploader for desktop I will not have bug ?

How did you upload your videos ?

Maybe the instructions are not clear, but you should definitely copy the files to the disk of the computer first.

? i use this command line
mapillary_tools send_videos_for_processing --advanced --video_import_path “/media/vincent/BLACKVUE/BlackVue/Record/” --user_name “numetlib”

you say that i must copy to the disk of my computer before ?

I know nothing about the command tools. But in general, that would be a good idea.

if i well understand, you upload your video with “mapillary uploader for desktop” and don’t have time lapse betsween picture and gps.

Do you know if on your dashcam it’s mapillary firmware ou blackvue firmware ?

I got it from Mapillary, so it has the mapillary firmware.
But if I remember well, that means only that the settings are correct.

There are plenty of discussions here about the commandline upload.
But it remains a big problem.

ok, but i’m not sure to understand

when you use “mapillary uploader for desktop” you upload video or you make processing on your computer then upload picture ?

because with commandline upload, i upload video and mapillary’ server make processings. The lag between pictures and gps is due to processing i suppose, because gps is very good but associated picture is a wrong one !!!

good gps in a roundabout (https://www.mapillary.com/app/?lat=44.85851506582901&lng=-0.6774089016670359&z=17&tab=uploads&pKey=npC084uR09MqEglDruApYy&focus=map) and the good picture is 9 pictures before (https://www.mapillary.com/app/?lat=44.85849252747116&lng=-0.6770907415730337&z=17&tab=uploads&pKey=0qhSOeVPKL78kMydjpMN3S&focus=map)

thanks for yours answers

I just copy the files. I don’t remember where the GPS data is stored. A lot happens before the actual upload, but I don’t know what.
Bob, help Bob (3 times).

The GPS NMEA data stream is actually embedded in the mp4 file. Judging by my occasional looks at code and processing, mapillary_tools parses the mp4 to create GPS gpx files. This then becomes the source for geoencoding.

It would seem that the NMEA data is thus synced to specific frames but I think the tools simply use the frame timestamp against the interpolated gpx data.

The camera also creates x.gps files per mp4 that seem to be a proprietary modification of the NMEA data. I assume for their own phone/viewing interface. These can be downloaded via the WiFi. I run a rough script to convert these for my own purpose;

cat *.gps | uniq | cut -c 16- |grep GP| gpsbabel -i nmea -f - -o gpx,gpxver=1.0 -F 20200228BV.gpx

Hope this helps

ok, thanks a lot for your answer even i can’t understand :slight_smile:

I don’t know what to think about dashcam recommendations : " Direct Upload (Recommended)
“* Upload videos located in path/to/videos directly to Mapillary. Videos are moved to path/to/videos/uploaded folder after upload. Videos that do not contain valid imagery are not uploaded to minimize bandwidth usage. Sampling is performed in the cloud so no extra disk space is required. This command supports the front camera video from the Blackvue DR900s (1-channel and 2-channel) models.”

So if i make this, i obtain lag due to process on mapillary serveur :frowning: