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Generic AHD streaming dash camera with GPS(Jomise T860S-GM ) - need support for

Started by johnichan, November 03, 2022, 03:28:34 AM

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johnichan

Hi All,

I am starting a new topic as the "Extracting GPS Information from .MP4?" where Phil Harvey helped me to decode metadata of 70mai & post lot of dash camera images in Mappillary in India.

Now I am in Seattle and got a new dash camera where I need someone's help to start decoding and contributing my images to people.

The current dash camera files uploaded here.

https://drive.google.com/drive/folders/1BKF6qqYFQe4K1HHc7Roo5b-yRz20viQT?usp=share_link


My previous mapillary upload by using Phil's guidance is posted here

https://www.mapillary.com/app/user/johnichan


Phil Harvey

This is a new one for me.

I can see the GPS in this file and should be able to add support for this in ExifTool 12.50.

Note that you will need to use the -ee3 option to extract the GPS from these files.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

Phil Harvey

Oh no.  The dashcam is somehow obfuscating the coordinates in what would otherwise be a standard NMEA GPRMC sentence.  :(  (I have no idea why dashcam manufacturers do this, but it seems to be a common theme. I think it is stupid because anyone who wants to know them can use the manufacturer's software, so it doesn't do anything to help privacy, but it does prevent the camera owner from doing something useful with the metadata.  If I were you I would complain bitterly to the camera manufacturer.)

The format should be

$GPRMC,hhmmss.ss,A,ddmm.mmmmm,N,dddmm.mmmmm,W,spd(kts),dir(deg),DDMMYY,,*cs
But this is what the file contains:

$GPRMC,172255.00,A,:985.95194,N,17170.14674,W,029.678,170.68,240822,,,D*7B
$GPRMC,172255.00,A,:985.95194,N,17170.14674,W,029.678,170.68,240822,,,D*7B
$GPRMC,172256.00,A,:985.93359,N,17170.14349,W,029.340,170.97,240822,,,D*7D
$GPRMC,172257.00,A,:985.91542,N,17170.14076,W,028.338,171.24,240822,,,D*7B
$GPRMC,172257.00,A,:985.91542,N,17170.14076,W,028.338,171.24,240822,,,D*7B
$GPRMC,172258.00,A,:985.89817,N,17170.13818,W,028.283,171.26,240822,,,D*73
$GPRMC,172258.00,A,:985.89817,N,17170.13818,W,028.283,171.26,240822,,,D*73
$GPRMC,172259.00,A,:985.88037,N,17170.13568,W,028.096,171.37,240822,,,D*79
$GPRMC,172259.00,A,:985.88037,N,17170.13568,W,028.096,171.37,240822,,,D*79
$GPRMC,172300.00,A,:985.86266,N,17170.13331,W,027.911,171.65,240822,,,D*7E
$GPRMC,172300.00,A,:985.86266,N,17170.13331,W,027.911,171.65,240822,,,D*7E
$GPRMC,172301.00,A,:985.84538,N,17170.13101,W,027.589,171.66,240822,,,D*72
$GPRMC,172301.00,A,:985.84538,N,17170.13101,W,027.589,171.66,240822,,,D*72
$GPRMC,172302.00,A,:985.82841,N,17170.12886,W,027.525,172.03,240822,,,D*76
$GPRMC,172302.00,A,:985.82841,N,17170.12886,W,027.525,172.03,240822,,,D*76
$GPRMC,172303.00,A,:985.81098,N,17170.12706,W,027.842,171.85,240822,,,D*79
$GPRMC,172303.00,A,:985.81098,N,17170.12706,W,027.842,171.85,240822,,,D*79
$GPRMC,172304.00,A,:985.79352,N,17170.12501,W,028.381,172.40,240822,,,D*77
$GPRMC,172304.00,A,:985.79352,N,17170.12501,W,028.381,172.40,240822,,,D*77
$GPRMC,172305.00,A,:985.77523,N,17170.12299,W,028.907,172.84,240822,,,D*71
$GPRMC,172305.00,A,:985.77523,N,17170.12299,W,028.907,172.84,240822,,,D*71
$GPRMC,172306.00,A,:985.75651,N,17170.12084,W,029.296,173.01,240822,,,D*7E
$GPRMC,172306.00,A,:985.75651,N,17170.12084,W,029.296,173.01,240822,,,D*7E
$GPRMC,172307.00,A,:985.73820,N,17170.11869,W,029.778,172.36,240822,,,D*7D
$GPRMC,172307.00,A,:985.73820,N,17170.11869,W,029.778,172.36,240822,,,D*7D
$GPRMC,172308.00,A,:985.71962,N,17170.11624,W,029.924,172.10,240822,,,D*7A
$GPRMC,172308.00,A,:985.71962,N,17170.11624,W,029.924,172.10,240822,,,D*7A
$GPRMC,172309.00,A,:985.70025,N,17170.11410,W,029.947,172.07,240822,,,D*72
$GPRMC,172309.00,A,:985.70025,N,17170.11410,W,029.947,172.07,240822,,,D*72
$GPRMC,172310.00,A,:985.68110,N,17170.11208,W,029.592,172.50,240822,,,D*7D
$GPRMC,172310.00,A,:985.68110,N,17170.11208,W,029.592,172.50,240822,,,D*7D
$GPRMC,172311.00,A,:985.66260,N,17170.11031,W,029.884,173.08,240822,,,D*7A
$GPRMC,172311.00,A,:985.66260,N,17170.11031,W,029.884,173.08,240822,,,D*7A
$GPRMC,172312.00,A,:985.64423,N,17170.10880,W,029.803,172.65,240822,,,D*71
$GPRMC,172312.00,A,:985.64423,N,17170.10880,W,029.803,172.65,240822,,,D*71
$GPRMC,172313.00,A,:985.62583,N,17170.10657,W,029.608,171.91,240822,,,D*7D
$GPRMC,172313.00,A,:985.62583,N,17170.10657,W,029.608,171.91,240822,,,D*7D
$GPRMC,172314.00,A,:985.60671,N,17170.10419,W,029.712,171.97,240822,,,D*7F
$GPRMC,172314.00,A,:985.60671,N,17170.10419,W,029.712,171.97,240822,,,D*7F
$GPRMC,172315.00,A,:985.58673,N,17170.10175,W,030.055,172.23,240822,,,D*71
$GPRMC,172315.00,A,:985.58673,N,17170.10175,W,030.055,172.23,240822,,,D*71
$GPRMC,172316.00,A,:985.56727,N,17170.09932,W,030.617,172.33,240822,,,D*71
$GPRMC,172316.00,A,:985.56727,N,17170.09932,W,030.617,172.33,240822,,,D*71
$GPRMC,172317.00,A,:985.54710,N,17170.09688,W,031.155,172.20,240822,,,D*77
$GPRMC,172317.00,A,:985.54710,N,17170.09688,W,031.155,172.20,240822,,,D*77
$GPRMC,172318.00,A,:985.52688,N,17170.09445,W,031.546,171.100,240822,,,D*48
$GPRMC,172318.00,A,:985.52688,N,17170.09445,W,031.546,171.100,240822,,,D*48
$GPRMC,172319.00,A,:985.50634,N,17170.09201,W,031.882,172.29,240822,,,D*7C
$GPRMC,172319.00,A,:985.50634,N,17170.09201,W,031.882,172.29,240822,,,D*7C
$GPRMC,172320.00,A,:985.48608,N,17170.08978,W,032.276,172.50,240822,,,D*7C
$GPRMC,172320.00,A,:985.48608,N,17170.08978,W,032.276,172.50,240822,,,D*7C
$GPRMC,172321.00,A,:985.46570,N,17170.08735,W,032.455,172.55,240822,,,D*7F
$GPRMC,172321.00,A,:985.46570,N,17170.08735,W,032.455,172.55,240822,,,D*7F
$GPRMC,172322.00,A,:985.44567,N,17170.08491,W,032.072,172.65,240822,,,D*79
$GPRMC,172322.00,A,:985.44567,N,17170.08491,W,032.072,172.65,240822,,,D*79
$GPRMC,172323.00,A,:985.42531,N,17170.08241,W,032.113,172.49,240822,,,D*74
$GPRMC,172323.00,A,:985.42531,N,17170.08241,W,032.113,172.49,240822,,,D*74
$GPRMC,172324.00,A,:985.40503,N,17170.07996,W,032.320,172.55,240822,,,D*73
$GPRMC,172324.00,A,:985.40503,N,17170.07996,W,032.320,172.55,240822,,,D*73
$GPRMC,172325.00,A,:985.38522,N,17170.07738,W,032.326,172.51,240822,,,D*7D
$GPRMC,172325.00,A,:985.38522,N,17170.07738,W,032.326,172.51,240822,,,D*7D
$GPRMC,172326.00,A,:985.36489,N,17170.07493,W,032.784,172.55,240822,,,D*75
$GPRMC,172326.00,A,:985.36489,N,17170.07493,W,032.784,172.55,240822,,,D*75
$GPRMC,172327.00,A,:985.34500,N,17170.07279,W,032.467,172.72,240822,,,D*73
$GPRMC,172327.00,A,:985.34500,N,17170.07279,W,032.467,172.72,240822,,,D*73
$GPRMC,172328.00,A,:985.32453,N,17170.07077,W,032.239,172.84,240822,,,D*7F
$GPRMC,172328.00,A,:985.32453,N,17170.07077,W,032.239,172.84,240822,,,D*7F
$GPRMC,172329.00,A,:985.30431,N,17170.06841,W,032.177,172.73,240822,,,D*70
$GPRMC,172329.00,A,:985.30431,N,17170.06841,W,032.177,172.73,240822,,,D*70
$GPRMC,172330.00,A,:985.28407,N,17170.06590,W,032.421,172.40,240822,,,D*77
$GPRMC,172330.00,A,:985.28407,N,17170.06590,W,032.421,172.40,240822,,,D*77
$GPRMC,172331.00,A,:985.26330,N,17170.06346,W,033.069,172.38,240822,,,D*7E
$GPRMC,172331.00,A,:985.26330,N,17170.06346,W,033.069,172.38,240822,,,D*7E
$GPRMC,172332.00,A,:985.24244,N,17170.06115,W,033.937,172.61,240822,,,D*73
$GPRMC,172332.00,A,:985.24244,N,17170.06115,W,033.937,172.61,240822,,,D*73
$GPRMC,172333.00,A,:985.22126,N,17170.05858,W,034.406,172.47,240822,,,D*78
$GPRMC,172333.00,A,:985.22126,N,17170.05858,W,034.406,172.47,240822,,,D*78
$GPRMC,172334.00,A,:985.19927,N,17170.05585,W,034.467,172.43,240822,,,D*7B
$GPRMC,172334.00,A,:985.19927,N,17170.05585,W,034.467,172.43,240822,,,D*7B
$GPRMC,172335.00,A,:985.17772,N,17170.05315,W,033.977,172.36,240822,,,D*7E
$GPRMC,172335.00,A,:985.17772,N,17170.05315,W,033.977,172.36,240822,,,D*7E
$GPRMC,172336.00,A,:985.15617,N,17170.05043,W,033.858,172.41,240822,,,D*76
$GPRMC,172336.00,A,:985.15617,N,17170.05043,W,033.858,172.41,240822,,,D*76
$GPRMC,172337.00,A,:985.13535,N,17170.04797,W,033.389,172.46,240822,,,D*7B
$GPRMC,172337.00,A,:985.13535,N,17170.04797,W,033.389,172.46,240822,,,D*7B
$GPRMC,172338.00,A,:985.11456,N,17170.04568,W,032.963,172.65,240822,,,D*75
$GPRMC,172338.00,A,:985.11456,N,17170.04568,W,032.963,172.65,240822,,,D*75
$GPRMC,172339.00,A,:985.09397,N,17170.04325,W,032.351,172.51,240822,,,D*71
$GPRMC,172339.00,A,:985.09397,N,17170.04325,W,032.351,172.51,240822,,,D*71
$GPRMC,172340.00,A,:985.07295,N,17170.04038,W,032.265,172.08,240822,,,D*76
$GPRMC,172340.00,A,:985.07295,N,17170.04038,W,032.265,172.08,240822,,,D*76
$GPRMC,172341.00,A,:985.05274,N,17170.03756,W,031.731,172.20,240822,,,D*7B
$GPRMC,172341.00,A,:985.05274,N,17170.03756,W,031.731,172.20,240822,,,D*7B
$GPRMC,172342.00,A,:985.03256,N,17170.03535,W,031.840,172.54,240822,,,D*76
$GPRMC,172342.00,A,:985.03256,N,17170.03535,W,031.840,172.54,240822,,,D*76
$GPRMC,172343.00,A,:985.01262,N,17170.03313,W,032.013,172.69,240822,,,D*7D
$GPRMC,172343.00,A,:985.01262,N,17170.03313,W,032.013,172.69,240822,,,D*7D
$GPRMC,172344.00,A,:984.99259,N,17170.03084,W,032.362,172.42,240822,,,D*7A
$GPRMC,172344.00,A,:984.99259,N,17170.03084,W,032.362,172.42,240822,,,D*7A
$GPRMC,172345.00,A,:984.97265,N,17170.02848,W,032.230,172.48,240822,,,D*7D
$GPRMC,172345.00,A,:984.97265,N,17170.02848,W,032.230,172.48,240822,,,D*7D
$GPRMC,172346.00,A,:984.95227,N,17170.02618,W,032.437,172.44,240822,,,D*73
$GPRMC,172346.00,A,:984.95227,N,17170.02618,W,032.437,172.44,240822,,,D*73
$GPRMC,172347.00,A,:984.93180,N,17170.02373,W,032.180,172.07,240822,,,D*7E
$GPRMC,172347.00,A,:984.93180,N,17170.02373,W,032.180,172.07,240822,,,D*7E
$GPRMC,172348.00,A,:984.91135,N,17170.02159,W,032.096,171.93,240822,,,D*7E
$GPRMC,172348.00,A,:984.91135,N,17170.02159,W,032.096,171.93,240822,,,D*7E
$GPRMC,172349.00,A,:984.89061,N,17170.01878,W,032.174,171.98,240822,,,D*73
$GPRMC,172349.00,A,:984.89061,N,17170.01878,W,032.174,171.98,240822,,,D*73
$GPRMC,172350.00,A,:984.87053,N,17170.01635,W,032.010,171.80,240822,,,D*79
$GPRMC,172350.00,A,:984.87053,N,17170.01635,W,032.010,171.80,240822,,,D*79
$GPRMC,172351.00,A,:984.85031,N,17170.01371,W,032.387,171.67,240822,,,D*78
$GPRMC,172351.00,A,:984.85031,N,17170.01371,W,032.387,171.67,240822,,,D*78
$GPRMC,172352.00,A,:984.82936,N,17170.01112,W,032.577,171.76,240822,,,D*70
$GPRMC,172352.00,A,:984.82936,N,17170.01112,W,032.577,171.76,240822,,,D*70
$GPRMC,172353.00,A,:984.80910,N,17170.00896,W,032.349,171.96,240822,,,D*7F
$GPRMC,172353.00,A,:984.80910,N,17170.00896,W,032.349,171.96,240822,,,D*7F
$GPRMC,172354.00,A,:984.78824,N,17170.00689,W,032.282,171.96,240822,,,D*74
$GPRMC,172354.00,A,:984.78824,N,17170.00689,W,032.282,171.96,240822,,,D*74
$GPRMC,172355.00,A,:984.76779,N,17170.00473,W,032.219,172.04,240822,,,D*7B
$GPRMC,172355.00,A,:984.76779,N,17170.00473,W,032.219,172.04,240822,,,D*7B

The coordinates don't make sense (eg. the latitude degrees are ":9" but should be "47").  Life is never easy.  :(

If I can figure this out I'll need another moving video shot at another location to verify that the decoding is working.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

Phil Harvey

I've spent some time working on this.  It isn't going to be easy, and will require a longer video at a different location to be able to decrypt this.  Preferably one travelling in a straight line at a constant speed.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

johnichan

Hi,

Sorry for the long delay in response. The camera vendor says he will replace the camera for this defect, but no firmware update to fix it. Interestingly DVplayer(also decode wrong as seen in the screenshot) is costing 10$ which is linked with the key behind the recorder. The key behind my dash camera was used by someone, and I got another key when I complained in customer care. There are already 2 videos added to the folder after resetting the settings as instructed by customer care,but its in the same location.

I will send interstate videos today, which are around 60MPH, but 1-minute videos. To get 1 degree change I need to travel more than 120km(90MILES) for a different location to make 47 to 46 or 48. This is challenging in the Winter. I will try it later and update.

Pasting the old link again.
https://drive.google.com/drive/folders/1BKF6qqYFQe4K1HHc7Roo5b-yRz20viQT?usp=share_link


johnichan

Hi,

I added a few more random files for cross-checking if it helps.
Pasting the old link again.
https://drive.google.com/drive/folders/1BKF6qqYFQe4K1HHc7Roo5b-yRz20viQT?usp=share_link


I got another chinese rebranded dash camera which i returned due to issues in recording. this is Lamtto brand 4k dvr.

the files I got from it is listed here https://drive.google.com/drive/folders/1CSLWgs3gnFqgT6XVxn12CqcfNhtZfh2-?usp=share_link




Phil Harvey

ExifTool 12.50 does a better job of extracting the GPS coordinates from these "random" TS samples, but as expected it isn't very accurate.  I can't generate an accurate calibration from samples which are so close together.

The MP4 samples contain encrypted coordinates like a number of other Chinese dashcams, and I haven't yet been able to decrypt these.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

johnichan

i will update with new files once I start travelling during x mass time.

Phil Harvey

Thanks.  I don't need really long files, just files which are shot in widely separated locations.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

johnichan

Hey, I have an update. The Jomise had offered me a new gps module and I traveled to Houston on flight with it and tested in houston. I found it works without issues in houston, but on coming back same issue in Seattle location. So its some issue related to co-ordinate encoding.

https://drive.google.com/drive/folders/1BKF6qqYFQe4K1HHc7Roo5b-yRz20viQT?usp=sharing

check new_gps folder.

Phil Harvey

...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).


Phil Harvey

Sorry, I'm a little behind in my to-do list at the moment.  :(  No progress yet, but I haven't forgotten.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

Phil Harvey

As I suspected, my de-obfuscation for Seattle doesn't work for the video shot in Houston.  I don't understand why you say it works without issues in Houston, because the stored metadata is:

$GPRMC,002816.00,A,6820.67273,N,13424.26599,W,000.045,000.00,261122,,,A*79
$GPRMC,002816.00,A,6820.67273,N,13424.26599,W,000.045,000.00,261122,,,A*79
$GPRMC,002817.00,A,6820.67273,N,13424.26599,W,000.006,000.00,261122,,,A*7F
$GPRMC,002817.00,A,6820.67273,N,13424.26599,W,000.006,000.00,261122,,,A*7F
$GPRMC,002818.00,A,6820.67273,N,13424.26599,W,000.050,000.00,261122,,,A*73
$GPRMC,002818.00,A,6820.67273,N,13424.26599,W,000.050,000.00,261122,,,A*73
$GPRMC,002819.00,A,6820.67273,N,13424.26599,W,000.017,000.00,261122,,,A*71
$GPRMC,002819.00,A,6820.67273,N,13424.26599,W,000.017,000.00,261122,,,A*71
$GPRMC,002820.00,A,6820.67273,N,13424.26602,W,000.088,000.00,261122,,,A*7F
$GPRMC,002820.00,A,6820.67273,N,13424.26602,W,000.088,000.00,261122,,,A*7F

Which is around 68N 134W, but Houston is around 29N 95W.

If I use the same algorithm as I developed for Seattle to de-obfuscate the Houston coordinates, it gives 86N 166W which is clearly wrong.  So a more general algorithm is required.

You should complain bitterly to the cam manufacturer about obfuscating the coordinates like this because I at this point I don't think I'll be able to compensate for this.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).