ExifTool Forum

ExifTool => Newbies => Topic started by: giuli on January 08, 2020, 12:53:52 PM

Title: Accelerometer data of vantrue n2 dashcam
Post by: giuli on January 08, 2020, 12:53:52 PM
Hello!
I would like to extract the accelerometer data from a vantrue n2 dashcam video. Have someone done it? I've tried some of the methods found here in the forum for other cameras but they do not work.
Thank you very much!
Giulia
Title: Re: Accelerometer data of vantrue n2 dashcam
Post by: StarGeek on January 08, 2020, 01:00:37 PM
Can you post a small sample from a moving video with the approximate GPS coordinates?
Title: Re: Accelerometer data of vantrue n2 dashcam
Post by: giuli on January 09, 2020, 05:15:36 AM
Calling exiftool like this

exiftool -ee -echo "Lat,Lon,Speed,DateTime" -n -p "$gpslatitude,$gpslongitude,$gpsspeed,$gpsdatetime" test.mov > out.csv

I have an output of this type:


Lat Lon Speed DateTime
46.09000833 11.1266 0.57412 2019:12:04 14:09:50Z
46.08999833 11.12659 0.51856 2019:12:04 14:09:51Z
46.09000833 11.12664 0.87044 2019:12:04 14:09:52Z
46.09001833 11.12666 0.90748 2019:12:04 14:09:53Z
46.09002333 11.126605 0.85192 2019:12:04 14:09:54Z
46.09001 11.12660667 0.81488 2019:12:04 14:09:55Z
46.09000667 11.12660167 0.77784 2019:12:04 14:09:56Z
46.089995 11.126625 0.2778 2019:12:04 14:09:57Z
46.09 11.126625 0.20372 2019:12:04 14:09:58Z
46.09000667 11.12659833 0.94452 2019:12:04 14:09:59Z
46.09002667 11.12660833 2.75948 2019:12:04 14:10:00Z
46.09002833 11.12663833 5.3708 2019:12:04 14:10:01Z
46.09001333 11.12659333 2.51872 2019:12:04 14:10:02Z


This is only a part of the output because the video is of 5 minutes. If the video is needed I can send it by mail or message, maybe?
Title: Re: Accelerometer data of vantrue n2 dashcam
Post by: Phil Harvey on January 09, 2020, 07:40:39 AM
If the accelerometer data isn't already in the output of this command, then upload a video and I'll try to decode it.

exiftool -ee -G3 FILE

- Phil
Title: Re: Accelerometer data of vantrue n2 dashcam
Post by: giuli on January 09, 2020, 08:44:49 AM
No there isn't in the output of that command. The video that I have is too big to upload it here, can I send to you by mail?
Thank you very much
Title: Re: Accelerometer data of vantrue n2 dashcam
Post by: Phil Harvey on January 09, 2020, 08:52:42 AM
You can try emailing it.  My email is philharvey66 at gmail.com

- Phil
Title: Re: Accelerometer data of vantrue n2 dashcam
Post by: giuli on January 09, 2020, 02:38:19 PM
I sent the email!
Thank you!
Title: Re: Accelerometer data of vantrue n2 dashcam
Post by: Phil Harvey on January 09, 2020, 02:58:18 PM
I got the file, and I'll take a look at it in detail tomorrow, but it isn't going to be trivial to extract this.

Is there any software that displays the accelerometer readings from this?  It would help if I knew what they should be.

- Phil
Title: Re: Accelerometer data of vantrue n2 dashcam
Post by: giuli on January 10, 2020, 06:37:51 AM
Here https://www.vantrue.net/Support/detail/id/23.html you will find the software of the camera.

Giulia
Title: Re: Accelerometer data of vantrue n2 dashcam
Post by: Phil Harvey on January 10, 2020, 09:53:49 AM
Thanks.  This helped a lot.

I've just released ExifTool 11.84 (https://exiftool.org/) with the ability to extract Accelerometer using the -ee option from the video you provided.

Note that that software you referenced subtracts 1 from the X component of the Accelerometer, but in the video you posted this should actually be subtracted from the Y component.  This will be different depending on the camera orientation.  ExifTool doesn't do this subtraction.

- Phil
Title: Re: Accelerometer data of vantrue n2 dashcam
Post by: giuli on January 13, 2020, 03:55:13 AM
Thank you very much for your help Phil!

Giulia