XGODY 12" 4K Dashcam - extracting GPS, vibration data from MP$

[Engineer_GLTECH]

The Dashcam I recently acquired from eBay generates MP$ files. I need to extract GPS coordinates and vibration sensor data that it saves. I currently use GXPlayer to review files. But I would like to extract them and save as CVS file of something similar. The link to file is as follows.

https://www.dropbox.com/scl/fi/46uko1osvglnlp9kfvrxb/Share_DashVid.mp4?rlkey=mjij0f7a55gkhlaj2e7ubfqb6&st=hgjft0k0&dl=0

Thanks in advance.

[Phil Harvey]

I can see the GPS in this video.  Unless I post back here with problems, expect this to be extracted by ExifTool 12.90 when it is released.

- Phil

[Phil Harvey]

A couple of questions:

1. The GPS data says you are going about 52 "km/h" during this video, but it looks more like 52 mph to me.  Which is it?

2. There is an "H" reading in the data that decreases from 361.3 at the start of the video to 245.0 at the end.  Perhaps this is supposed to be elevation (height)?  But it looks like your elevation should be about 200m for the entire video.

Another sample from a different location where you go around some corners and change speed a bit would help figure these out.  A straight line course at constant speed doesn't give me much to work with.

- Phil

[Engineer_GLTECH]

Phil, That is great. I look forward to Ver-12.9.
The speeds should be in MPH. I know the speed shown by car odometer and the one shown on the top left corner in the video matches. 
I have more video files. Let me verify and send you

[Engineer_GLTECH]

OK. Here is another video file.
https://www.dropbox.com/scl/fi/4qyrsod0ah6o9qgby2h2f/20240520_220727F.mp4?rlkey=tytde6svab4cp9035ve56jn7x&st=xtw5ck9c&dl=0

I am also interested in fetching the Accelerometer data.
Currently I use GXPlayer from following link.

https://sourceforge.net/projects/gxplayer-v4-2-8/

It can load up to three video files (Front, Rear and Incar camera) and play it simultaneously/ synchronously while showing a map and car's current position during that 3 or 5 minute clip that it's playing. It also plots accelerometer data as car is moving.

[Engineer_GLTECH]

I am in Industrial automation field with relative decent software experience.
I intend to create a software utility that will scan through the stash of dashcam video files that i have accumulated over the week and identify the files where

1) the car was moving
2) Accelerometer showed bump or hit
3) total miles travelled that week
4) etc. etc. (TBD)

I do leave the dashcam on when I am parked at work or parked at home but on the side street. If there is a hit and run situation I would like to identify the culprit.

Ffmpeg and Exiftool will be a big part of that windows software.  I hope there will be people out there who would help me test such a software.

[Phil Harvey]

Thanks.  I can extract the Accelerometer and GPSTrack, but there is still an unknown value I can't figure out.  For this track the value starts at 237.1 and goes up to 350.1

- Phil

[Engineer_GLTECH]

Phil,

No idea Sir.
According to Google average Elevation of the neighborhood I am travelling through is ~ 180 feet. I wonder if those numbers are reflecting that as the car is moving.
If I can think of something else I will report.
I am open to sending more video files if that would help you.

Thanks again for looking into it.

[Phil Harvey]

Do you have any files where the elevation changes significantly, or taken in a location with a very different altitude?  GPS elevation is notoriously inaccurate, so I'm still thinking there is a chance this could be it.

- Phil

[Engineer_GLTECH]

Phil,

I sent you a link for a Dash cam video file when the car was parked and GPS didn't have lock so all values were zeros.
Unfortunately i don't have access to my HD at this moment but I really doubt if I have any file that has significant elevation changes.
The link was sent to your Gmail address. I hope you are ok with that.
Thanks

[Phil Harvey]

Links to my email are fine.  Usually that is how I request samples in case people don't want to make them public.

The way I've done things, ExifTool won't extract any timed metadata from this latest sample.

Regarding the unknown values, for now I'll extract them as "Unknown_H" if the Unknown (-u) option is used.

I think that's about as much as I can do for now.  This update will appear in version 12.90 when it is released, but if you tell me what system you are using I can make a pre-release available.

- Phil

[Engineer_GLTECH]

Phil,
Thanks for looking into it.
I am using Windows 10 .
Pre release would be nice. I can test drive the tool with files I have and report how it's doing for me.

[Phil Harvey]

Try this:  exiftool-12.90p_64.zip

- Phil

[Engineer_GLTECH]

Phil,
It's working great on few of the files I tried. I will run more files later tonight and provide an update.
I am just using -ee option to extract all the tags and then parsing them to get what is required. I am assuming the speed is in km/h.
Any idea why it's showing Z at the end of 'GPS Date/Time'

Thanks a lot

[StarGeek]

Any idea why it's showing Z at the end of 'GPS Date/Time'

It stands for Zulu Time, i.e. another format for UTC time.

The time zone using UTC is sometimes denoted UTC±00:00 or by the letter Z—a reference to the equivalent nautical time zone (GMT), which has been denoted by a Z since about 1950.

[Engineer_GLTECH]

Thanks StarGeek.

[Phil Harvey]

Correct.  Speed is in km/h.  I was assuming the stored time stored was UTC (zulu), but let me know if it is otherwise.

- Phil

[Phil Harvey]

I've just looked at your screen captures.  You might consider using this command to extract the data in CSV format:

Code Select Expand

exiftool -ee -n -p "$GPSDateTime,$GPSLatitude,$GPSLongitude,$GPSSpeed,$GPSTrack,$Accelerometer" FILE
- Phil