Inverse geotagging from NextBase 622GW dashcam video

[ekantons]

I am trying to extract the GPS data from a Nextbase 622GW dashcam MP4 video.  I have not had success following the example commands/switches for the Nextbase 512 camera.
The output for the first 1050 byte block of GPS data from:
exiftool -ee -v4 videofile.mp4
is below.
The date/time stamp can be seen (20200101000005) starting at the 6th byte of the block, but the remainder of the data appears to be binary.
Can you help decode it and let me know the exiftool command switches?

---- Extract Embedded ----
Track3 Type='text' Format='text', Sample 1 of 600 (1050 bytes)
   5b848: 04 18 00 00 00 00 32 30 32 30 30 31 30 31 30 30 [......2020010100]
   5b858: 30 30 30 35 00 00 2a 00 40 00 54 ff dc fe f5 06 [0005..*.@.T.....]
   5b868: 19 ff b5 fb 0a 00 8c ff a4 fe f1 06 1f ff b5 fb [................]
   5b878: 12 00 1a ff 96 fe 03 07 2b ff b0 fb 20 00 de fe [........+... ...]
   5b888: d8 fe e8 06 2a ff ad fb 2e 00 e8 fe e6 fe ea 06 [....*...........]
   5b898: 28 ff ad fb 2a 00 60 ff 0a ff ee 06 1e ff ad fb [(...*.`.........]
   5b8a8: 16 00 52 ff 10 ff f1 06 11 ff af fb 16 00 56 ff [..R...........V.]
   5b8b8: 14 ff f7 06 15 ff c9 fb 04 00 16 ff ea fe ee 06 [................]
   5b8c8: 1e ff ba fb 1e 00 44 ff 00 ff fb 06 21 ff bd fb [......D.....!...]
   5b8d8: 32 00 0e ff 2e ff f2 06 08 ff bb fb 16 00 28 ff [2.............(.]
   5b8e8: 1c ff e8 06 1e ff bb fb 36 00 16 ff 40 ff ed 06 [........6...@...]
   5b8f8: 1b ff c9 fb 3a 00 12 ff 3e ff fa 06 20 ff bb fb [....:...>... ...]
   5b908: 0e 00 40 ff 1c ff f1 06 1b ff c2 fb 28 00 32 ff [..@.........(.2.]
   5b918: 4e ff 04 07 22 ff bc fb 14 00 42 ff 32 ff e8 06 [N...".....B.2...]
   5b928: 10 ff c8 fb dc ff 36 ff ee fe f6 06 1c ff ca fb [......6.........]
   5b938: f8 ff d2 fe 1c ff fe 06 24 ff be fb 0e 00 b0 fe [........$.......]
   5b948: 52 ff eb 06 17 ff cb fb 06 00 f2 fe 38 ff 0d 07 [R...........8...]
   5b958: 1d ff cf fb fe ff 36 ff 2a ff e7 06 1f ff c9 fb [......6.*.......]
   5b968: 04 00 1c ff 0a ff e5 06 25 ff be fb 0a 00 b8 fe [........%.......]
   5b978: 1c ff f2 06 08 ff b3 fb 0a 00 74 fe 0a ff ef 06 [..........t.....]
   5b988: 1b ff bd fb 12 00 80 fe 22 ff 03 07 0d ff ae fb [........".......]
   5b998: 32 00 c4 fe 3c ff ee 06 0c ff b4 fb 1e 00 20 ff [2...<......... .]
   5b9a8: 2a ff e4 06 14 ff c5 fb 30 00 ea fe 50 ff 01 07 [*.......0...P...]
   5b9b8: 17 ff cb fb 12 00 b8 fe 36 ff e9 06 11 ff bf fb [........6.......]
   5b9c8: 32 00 8a fe 74 ff fb 06 07 ff a3 fb 48 00 9c fe [2...t.......H...]
   5b9d8: a6 ff e2 06 1a ff b6 fb 28 00 dc fe 9e ff e5 06 [........(.......]
   5b9e8: fb fe b7 fb 46 00 fa fe b0 ff f3 06 1d ff ba fb [....F...........]
   5b9f8: 16 00 2a ff 70 ff fe 06 04 ff ba fb 1c 00 ec fe [..*.p...........]
   5ba08: 4c ff e7 06 13 ff bc fb 18 00 d4 fe 3e ff e9 06 [L...........>...]
   5ba18: 05 ff b6 fb 0c 00 be fe 36 ff e5 06 01 ff b7 fb [........6.......]
   5ba28: 02 00 d0 fe 1c ff ea 06 04 ff ab fb e6 ff f2 fe [................]
   5ba38: 08 ff d5 06 0d ff b3 fb f6 ff f6 fe fa fe f5 06 [................]
   5ba48: ef fe b2 fb 20 00 ea fe 18 ff f2 06 f2 fe b9 fb [.... ...........]
   5ba58: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5ba68: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5ba78: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5ba88: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5ba98: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5baa8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bab8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bac8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bad8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bae8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5baf8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bb08: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bb18: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bb28: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bb38: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bb48: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bb58: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bb68: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bb78: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bb88: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bb98: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bba8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bbb8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bbc8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bbd8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]
   5bbe8: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [................]

[Phil Harvey]

ExifTool should extract the GPS with the -ee option if it can decode it.  However, the data you posted is 6-axis accelerometer data, not GPS.

If you believe the file contains GPS data, you can send it to me and I'll see about adding support for decoding it.  My email is philharvey66 at gmail.com

- Phil

[havkacik]

Hi Phil.

It seems that I am not getting whole a lot from GPS or Acceleration data either from my Nextbase 622GW dashcam MP4 video. I am using exiftool -ee video.mpt option and got things like:

Code Select Expand

GPS Altitude                    : 189.6 m
GPS Dilution Of Precision      : 0.96
GPS Date/Time                  : 2024:02:12 10:58:59.500Z
GPS Latitude                    : 40 deg 5' 35.58" N
GPS Longitude                  : 10 deg 26' 15.40" E
GPS Satellites                  : 13
GPS Speed                      : 25.8465
GPS Track                      : 119.49
Image Size                      : 3840x2160
Megapixels                      : 8.3
Avg Bitrate                    : 44.2 Mbps
Rotation                        : 0
GPS Position                    : 40 deg 5' 35" N, 10 deg 26' 15.63" E
I know there is more contained withing the file, like SPEED or ACCELOROMETER data, e.g.:

• Actual Speed
• Max Speed
• Avg speed
• Distance passed
• Acc data: X
• Acc data: Y
• Acc data: Z

Is it possible somehow to detect it with ExifTool? Example of a file is attached under this location:

https://mega.nz/folder/cItzkAZB#ua-uc1jiB8p02XtDWcVBzA

[Phil Harvey]

Yes, there is information in this file that hasn't yet been decoded.

Do you have any utility to decode this?  If so, could you tell me the values for the first few samples so I know what to look for?

- Phil

[havkacik]

Hi Phil,

sorry for late reply. There is an utility called MyNextBase Player, which can be downloaded from the OEM of the dashcam site: https://nextbase.com/mynextbase-suite-feature

That could give you some pretty good idea about  SPEED or ACCELOROMETER values stored in the file. Could you please check whether you can decipher it with ExifTool somehow?

- Martin

[havkacik]

Hi Phil,

it also seems that the newest version 12.82 incorrectly exports GPS data from this particular MP4 file while previous version 12.56 did the correct GPS data export. I've attached bot GPX outputs and screenshots from the visualization software under the link to mega cloud. can you please check what is happening?

Regards, Martin

[Phil Harvey]

Hi Martin,

I see the issue.  ExifTool 12.82 decodes more GPS information from this file.  The track is stored twice in the file, and the older ExifTool extracted only one of these.  I think the 2nd one may be written by the Nextbase software.

You can ignore the other track by changing the IF condition in your gpx.fmt file to look specifically for the Track3 GPS:

Code Select Expand

#[IF]  $track3:gpslatitude $gpslongitude
- Phil

PH Edit: ExifTool 12.83 will have a new feature to allow you to use the original gpx.fmt file and ignore the other track by adding -api ignoregroups=nextbase to the command.