70mai A810 Dashcam Video GPS

[borism]

Hi there,

I have a sample of video from the 70mai A810 Dashcam and I'm not able to get exiftool to extract GPS data from it. I know other 70mai cameras work, so hoping this one can be enabled as well? Here is the sample (.rar file containing 2 .mp4s):
https://workupload.com/file/NmuG7FRncwL

Thank you so much!

[StarGeek]

Just to verify, these files have not been processed/edited by any software and are directly from the dashcam? Because any editing at all will remove all GPS tracks (and EXIF data).

Neither of these files have any time stamps, which would be very unusual. And they are HEVC, whereas most dashcams save in H.264 as it requires much less processing power.

Code Select Expand

C:\>exiftool -time:all --system:all -G1 -a -s Y:\!temp\x\y\70mai_Cam
======== Y:/!temp/x/y/70mai_Cam/NO20240926-161522-000300F.MP4
[QuickTime]     CreateDate                      : 0000:00:00 00:00:00
[QuickTime]     ModifyDate                      : 0000:00:00 00:00:00
[Track1]        TrackCreateDate                 : 0000:00:00 00:00:00
[Track1]        TrackModifyDate                 : 0000:00:00 00:00:00
[Track1]        MediaCreateDate                 : 0000:00:00 00:00:00
[Track1]        MediaModifyDate                 : 0000:00:00 00:00:00
[Track2]        TrackCreateDate                 : 0000:00:00 00:00:00
[Track2]        TrackModifyDate                 : 0000:00:00 00:00:00
[Track2]        MediaCreateDate                 : 0000:00:00 00:00:00
[Track2]        MediaModifyDate                 : 0000:00:00 00:00:00
======== Y:/!temp/x/y/70mai_Cam/NO20240926-161822-000301F.MP4
[QuickTime]     CreateDate                      : 0000:00:00 00:00:00
[QuickTime]     ModifyDate                      : 0000:00:00 00:00:00
[Track1]        TrackCreateDate                 : 0000:00:00 00:00:00
[Track1]        TrackModifyDate                 : 0000:00:00 00:00:00
[Track1]        MediaCreateDate                 : 0000:00:00 00:00:00
[Track1]        MediaModifyDate                 : 0000:00:00 00:00:00
[Track2]        TrackCreateDate                 : 0000:00:00 00:00:00
[Track2]        TrackModifyDate                 : 0000:00:00 00:00:00
[Track2]        MediaCreateDate                 : 0000:00:00 00:00:00
[Track2]        MediaModifyDate                 : 0000:00:00 00:00:00
    1 directories scanned
    2 image files read

[Phil Harvey]

The good news is that I can decode the GPS and speed from these videos.  The bad news is there are no timestamps in the GPS information, so you can extract your track, but won't be able to use it for geotagging.

- Phil

Edit: Maybe try setting the clock on the dashcam and recording a new video to see if the timestamps are set.

[borism]

Interesting, thanks Phil - do you have an example .gpx that you were able to extract from those videos?

[Phil Harvey]

Here you go.  This is the output from one of the videos.

- Phil

[borism]

Hi Phil,

It turns out there is a hidden .txt file that the camera creates together with the .mp4 video and there is a post in the mapillary community forum about how to parse that .txt file into a .gpx. Is doing that sort of conversion within the scope of what you might do in exiftool?

[Phil Harvey]

Perhaps.  Could you send me one of these files?  My email is philharvey66 at gmail.com

Make sure "exiftool" is somewhere in the email so it doesn't go to my junk box.

- Phil

[borism]

Thanks so much Phil! Here is a sample a user provided from a 70mai Dash Cam 4K A800S DVR which seems to use the same format as the A810:

• .txt file
• .mp4 file

Thank you again!

[Phil Harvey]

I got the files.  I can add support for geotagging images from the .txt file using the -geotag option if this helps.

- Phil

[borism]

Super, how will that work? Ideally I'm looking for something that transforms the .txt to a .gpx representing the same geotagged location information so it can be used together with the .mp4 video to plot the track.

[Phil Harvey]

Unfortunately, the -geotag feature won't give the gpx output file that you want.  I was hoping that you just wanted to gpx file to be able to geotag captures from along the track.  But this wouldn't allow you to plot the whole track.  The gpsbabel utility is designed specifically for this, but I don't know if it supports this particular format.  (It also has a github page.)

- Phil