Questions regarding openALPR and missing nvidia-related commands

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

So I’m trying to get openALPR Watchman Agent to run using the GPU of an Nvidia Jetson Nano.

  1. As I understood it there’s no need to install any drivers if you’ve installed the Nvidia Jetpack image and that with that I’m supposed to get things like
~/.tegrastats

to see GPU usage. This doesn’t work.

  1. Running openALPR Watchman Agent with hardware acceleration enabled yields a black picture and nothing happens. If I’m not supposed to install any drivers I’m kinda lost as to what I need to do to get the GPU to be usable by openALPR.

  2. Since CUDA came pre-installed I expected to be able to run nvcc right off the bat, but I first had to add cuda bins to the path. Maybe this should come pre-configured in the image and maybe it’s something related to this that’s causing my other problems?

Thanks

  • Joel

Edit:

bash <(curl https://deb.openalpr.com/install)

but doing so yields the following output:

The following packages have unmet dependencies:
openalprgpu: Depends: libalprocrgpu3 but it is not installable
             Depends: libalpredgegpu2 but it is not installable
             Depends: libalprneuralgpu2 but it is not installable
             Depends: libalprgpusupportcuda2 but it is not installable
2

Hi,

Jetson Nano is an ARM system.
It looks like there is no ARM package shared in this page:
[url]Rekor Documentation

May I know how do you setup the openALPR application?

Thanks.

3

This is most commonly caused by a missing Nvidia dependency when flashing (usually OpenCV). Make sure you select OpenCV when you flash the image.

If you want to track down the specific package, (assuming JetPack 4.2.x):

curl -L https://deb.openalpr.com/openalpr.gpg.key | sudo apt-key add -
echo ‘deb https://deb.openalpr.com/jetson40/ jetson40 main’ | sudo tee /etc/apt/sources.list.d/openalpr.list
sudo apt-get update
sudo apt-get install libalprneuralgpu2

You should see another output that lists which packages are not “installable” and “will not be installed”

The ones that will not be installed (e.g., Nvidia’s OpenCV package) means that the package is not available from any online repository. So you would need to get those by reflashing the device.

4

Hey Matt, thanks for the response.

I am just running a fresh installation on the Jetson.

Running the commmands you mentioned, seems like a bunch of things were installed (incl. libalprneuralgpu2).

Trying to run OpenALPR on GPU acceleration without success. I guess I should try to reflash. But I am not sure what to do different this time…

EDIT: Seems like after adding the openalpr repository I can now install all the packages which were not found. After adding the OpenALPR repo and manually installing the above packages - everything works! Recognition is blazing fast!

5

That is strange – I wonder if the install script did not detector your JetPack version. It checks your JetPack release version and sets up the appropriate APT repo.

Can you send the contents of this file:
/etc/nv_tegra_release

6

Hey,

Same trouble here…

Can’t find libalprocrgpu3 libalpredgegpu2 and libalprgpusupportcuda2 aren’t installable.

Can you explain how you add the openalpr repository?

[EDIT: Seems like after adding the openalpr repository I can now install all the packages which were not found. After adding the OpenALPR repo and manually installing the above packages - everything works! Recognition is blazing fast!
[/quote]

Do you mean the GitHub repository?

Thanks!