DashCam Footage - How to Check for GPS Data

MaFt

Hi all,

I'm currently reviewing GPS-enabled dashcam but no software is showing any GPS data on the files...

I know how to view EXIF data on photos but is there an equivalent way to view GPS data from a dashcam video?

It's saving the coordinates to the video so I know the GPS is working, I just can't seem to get the info from the video files themselves...

MaFt

Kremmen · Posted: Mon Sep 24, 2018 2:07 pm Post subject:

Not that I know of.

Even DashCam Viewer can't get at it so they get their own from the Google Maps sidebar.
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DashCam:
Viofo A119 V3

MaFt · Posted: Mon Sep 24, 2018 2:14 pm Post subject:

In which case I'm gonna take a guess that the DashCam is either faulty or they don't actually save the GPS to the file other than printing the location onto the video. Just a bit annoying that the software shows the map and accelerometer etc but then as soon as you hit play that all disappears. Seems a bit rubbish to be honest!

MaFt · Posted: Mon Sep 24, 2018 2:17 pm Post subject:

Kremmen · Posted: Mon Sep 24, 2018 2:32 pm Post subject:

Your first statement - the G force and map disappearing. That was a bug in early versions of Replay3.

The latest few versions should have fixed this.

Latest is 3.10.0

Failing that, scratch Replay, and try DashcamViewer which has the bonus of displaying the Lat/Long in Decimal Degrees instead of H:M:S

https://dashcamviewer.com/

Here is a recent screenshot of my Nextbase 380 using DCV:

Ignore the Dashboard size it's smaller than posted:

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DashCam:
Viofo A119 V3

M8TJT · Posted: Mon Sep 24, 2018 2:50 pm Post subject:

It obviously is possible to extract the GPS data from the files as Dashcam Viewer does it to display it as ddd.ddd rather than dd:mm:ss as per Replay.
But I haven't a clue how.

Kremmen · Posted: Mon Sep 24, 2018 3:05 pm Post subject:

My guess is that DCV are extracting the location data from their Google Map display as opposed to from the dashcam footage - but I could be wrong (again).

This is how I've got DCV configured (I don't want the G force data:

... and here is my Replay3 version:

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DashCam:
Viofo A119 V3

MaFt · Posted: Mon Sep 24, 2018 3:39 pm Post subject:

The CD came with Replay 3.4.1 on it. That's not showing any speed/location data.

Clicking 'help' and 'check for updates' did nothing. However, I went to the Nextbase site and downloaded the software from there which was 3.10.0 and that's all working now.

I guess 3.4.1 not only doesn't work correctly with the maps but also doesn't check for updated software correctly...!

MaFt · Posted: Mon Sep 24, 2018 3:40 pm Post subject:

Weirdly, DashCam Viewer doesn't show the location stuff but the updated version of Replay does now...

MaFt

Kremmen · Posted: Mon Sep 24, 2018 4:28 pm Post subject:

Might be worth checking the DashCam firmware version. If the CD was 3.4.1 then the firmware could be old as well.

I think 3.4.1 was the last version that didn't auto update. You may be able to update the dashcam firmware from Replay 3.10.0 as well.
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DashCam:
Viofo A119 V3

M8TJT · Posted: Mon Sep 24, 2018 7:00 pm Post subject:

pcaouolte · Posted: Mon Sep 24, 2018 7:01 pm Post subject:

GPS data from a dashcam is normally stored in the mp4 file but there is no universal standard like the exif data for jpg images.

The ones that I have looked at store the data within a "moov" atom inside the mp4 file. The structure of the data within the "moov" atom varies amongst dashcam makers and even differs amongst models from the same maker.

You either need a player specifically designed to handle data from that version of the dashcam or wait until the universal players like Dashcam viewer include support for your model.
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Paul

M8TJT · Posted: Mon Sep 24, 2018 7:15 pm Post subject:

Great info. Thanks.

Kremmen · Posted: Tue Sep 25, 2018 5:41 am Post subject:

Good point M8. Seems like a difficult task to extract it.

What I have found by running the Nextbase footage in DCV is that in both cases the positional data is updated visually about every second, but, not the same second.

So the actual position displayed in both DCV decimal and Nextbase H:M:S is never identical.

M8 calculated that at 60mph the position will change by about 200 feet each second. When we looked at the DCV v Replay position it was approx 100 feet different due to the update 'second' not being identical.

From that, it must be assumed that the saved GPS data isn't every second but a constant stream ?

This isn't Nextbase, but, here is an example of another DashCam data. It is held frame by frame apparently:

pcaouolte · Posted: Tue Sep 25, 2018 8:43 am Post subject:

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