NovaTrakt: Extract GPS data from your Viofo A119 [Windows]

[RobTrehy]

Version 2.1.1 has been released today, thanks to another video submission.

This version fixed an error when a Coordinate didn't include a decimal point.

 

[NeilinAsia]

Thank you for your efforts! It works great! But I noticed that when I want to change the destination folder to save the .GPX files in the same folder as the video files, it automatically creates a GPS subfolder and put GPX files in it.
Not a big deal, but if can correct the problem it would be perfect!

 

[RobTrehy]

Thank you for making me aware of this bug.

If you change the location of the output folder from the automatically calculated one, it currently has no effect on where your GPX files output.

This has now been fixed and will be included in the next release.

 

[Pav99]

I have recently bought an A119 cam and tried your app to extract the embedded GPS Data in order to use registratorviewer. The app runs and says that the extraction completed successfully. Unfortunately the resulting GPX files seem to be empty.

I have uploaded an example output file (extension changed to txt to allow uploading). there was correct gps data printed on the original mp4 recorded from my a119.

My situation might be different from others because my camera is very new with a v2.1 firmware dated 12/2016. has the GPS data embedding changed from one firmware to the next.

 

[RobTrehy]

Hi,

If NovaTrakt doesn't create a track in your GPX file, it's because it has been unable to locate or read the GPS data correctly.

This would suggest there have been further changes in the v2.1 firmware as you suggest.

Please could you email me a file, straight from your camera (please don't edit it as this will usually remove the GPS data), so that I can investigate. robert@robtrehy.co.uk

Thanks
Rob

 

[Pav99]

Hi Rob
Thanks for your work on this - I sent you a megafile upload link to a 3min mp4 file recorded today. There is GPS data present in the file.

The file was too large for the mailserver hence the upload link. Any work you can do on this would be greatly appreciated

Thanks - Pav

 

[RobTrehy]

Hi Pav,

Thanks for the file, I've downloaded it and can see that the data definitely isn't stored the same way. Just need to find it!

Rob

 

[Mtz]

Suggestions for 2.1.1
- add a checkbox to check/uncheck all loaded files
- add an abort button when NovaTrakt is processing the files. Or pressing again on Start Processing to abort processing. Now it is giving some warning.
- when clicking the „Name” tab to order the files based on names (is the same thing as based on date)
- remember last working folder
- if there is already a GPX file with the same name as the video file which NT want to process it, to not process again that GPX file. User to manually delete it if he wants another GPX file. At Status to offer an message as „Skipped (exits)” or something like that.
- maybe offer an message about empty GPX files and delete them after creation if are empty. As status something as Empty/Deleted or to delete that empty files when closing the program.

Your goal is to make the processing very fast. Ideal can be to launch only one application, for example:
- launch NT
- select files (not so nice because there is no video player, user will select based on date)
- offer an option to launch RV after processing the needed files. Maybe for this you will tell people to put the RV. exe into the same folder as NT. exe
The advantage of RV is that if using the Card, the RV will automatically scan the Card and when user is playing the video, there is already the GPX file.

enjoy,
Mtz

 

[neilmcl]

I have recently bought an A119 cam and tried your app to extract the embedded GPS Data in order to use registratorviewer. The app runs and says that the extraction completed successfully. Unfortunately the resulting GPX files seem to be empty.

I have uploaded an example output file (extension changed to txt to allow uploading). there was correct gps data printed on the original mp4 recorded from my a119.

My situation might be different from others because my camera is very new with a v2.1 firmware dated 12/2016. has the GPS data embedding changed from one firmware to the next.

As you may have read on your other thread I was having issues getting any GPS points extracted in my first attempt. The first file I extracted from was from where the car was parked up and stationary, it's possible that GPS points aren't recorded unles you're moving. The second file I used did extract multiple points and therefore worked perfectly in Registrator Viewer.

A big thanks Rob, btw.

 

[BCHobbyist]

As you may have read on your other thread I was having issues getting any GPS points extracted in my first attempt. The first file I extracted from was from where the car was parked up and stationary, it's possible that GPS points aren't recorded unles you're moving. The second file I used did extract multiple points and therefore worked perfectly in Registrator Viewer.

A big thanks Rob, btw.

It's very possible the clip you attempted to extract GPS data from dropped the GPS lock either at beginning of clip or near the end causing Rob's tool to not detect the known start/end locations. All GPS supported dashcams will have trouble locking the satellites, especially if in a tunnel/parking or near tall buildings or cliffs or the placement of the GPS unit and interference from other in-car devices. A119 seems to have a weaker than normal lock, possibly due to a longer re-sync function in the firmware. When combining a dozen or more clips there is always a GPS dropout with A119 cams. My other non-VIOFO dashcam doesn't have this weakness.

 

[mrb_2002]

Hi Pav,

Thanks for the file, I've downloaded it and can see that the data definitely isn't stored the same way. Just need to find it!

Rob

Hi Rob,
I also have a newly purchased (January 2017) A119 with the later firmware version (2.01) and i'm also experiencing the same issue of empty GPX files even though I can see that the GPS data (speed and co-ordinates) is successfully being recorded on the videos.
Frustratingly, there is no mention of this later firmware release on the viofo website.
Have you managed to identify the issue? Please let me know if you need me to send an example video file to troubleshoot further.
Thanks for all your hard work supporting this Dash cam

 

[RobTrehy]

Hi,

I have a sample file from a v2.01 camera, but as yet, have been unable to correctly identify the GPS data.

I've been a bit ill the past week, so didn't get too much time to look at it. Hopefully soon!

Rob

 

[Curtis54]

it would be interesting to share this sample file, Sergei or me may find the solution, you can use these websites to share the file :

http://www.zippyshare.com/
https://www.dropbox.com/?landing=fd

 

[RobTrehy]

The sample file I have came from @Pav99. It's not right that I share it, if he wants to he can.

 

[Curtis54]

if you ( or Pav99 ) don't want to share this sample file then I can understand,

one tip : the solution is often to change the value of the offset when you explore the binary file, it was the solution when the problem occured with the firmware v2.0, see the post of Sergei :

https://dashcamtalk.com/forum/threads/script-to-extract-gps-data-from-novatek-mp4.20808/page-4

you can use also a hex editor in order to compare what are the changes between firmware v2.0 and v2.1, if there is a small shift in the header, or if it's a more complex change ( like an obfuscation, a total change in the way where the gps data are coded, if Viofo wants to defeat free software like your, maybe they don't like the concept of open data, technical specifications of their way of handling GPS data in the MP4 file are still not available, we have to do a painful reverse-engineering )

 

[Pav99]

I don't want to share video publicly as it does contain GPS and other identifying info. I was happy to send it to Rob as he is developing his useful app but I think further sharing carries a potential risk I am not happy to take. I am not implying any disrespect to Curtis54 in this.

I can tell you that flashing my cam down to v2.0 firmware allowed me to use Novatrakt to extract GPS Data successfully from my A119. I am not 100% happy with this approach but it does allow me to work round one of the limitations of this cam.

 

[RobTrehy]

one tip : the solution is often to change the value of the offset when you explore the binary file, it was the solution when the problem occured with the firmware v2.0, see the post of Sergei :

https://dashcamtalk.com/forum/threads/script-to-extract-gps-data-from-novatek-mp4.20808/page-4

I don't think it's the header, as I am still able to find the GPS data atom. The problem is the GPS data atom is now 90% 0's/empty...

 

[NeilinAsia]

I don't think it's the header, as I am still able to find the GPS data atom. The problem is the GPS data atom is now 90% 0's/empty...

Yes I had to downgrade from FW 2.01 to 2.00 to use your script and Dashcam Viewer as it seems (I guess is a FW bug) FW 2.01 doesn't write correctly GPS metadata in MP4 file.

 

[Curtis54]

I don't think it's the header, as I am still able to find the GPS data atom. The problem is the GPS data atom is now 90% 0's/empty...

check with a hex editor and compare with a v2.0 sample binary file, in order to locate these GPS data bits

 

[BCHobbyist]

Yes I had to downgrade from FW 2.01 to 2.00 to use your script and Dashcam Viewer as it seems (I guess is a FW bug) FW 2.01 doesn't write correctly GPS metadata in MP4 file.

before you downgraded did you notice the FW 2.01 clips had lower than usual audio volume?