Has anyone on here installed MRL on a raspberry pi 2 running Raspbian?  I've got it mostly installed but opencv won't start my camera.  When I click capture I get an bunch of errors like these

 ERROR>> Caused by: java.lang.UnsatisfiedLinkError: /tmp/javacpp55587950902807/libjniopencv_highgui.so: libunicap.so.2: cannot open shared object file: No such file or directory

39579 [StreamGobbler_ERROR] INFO  class org.myrobotlab.framework.StreamGobbler  - ERROR>> at java.lang.ClassLoader$NativeLibrary.load(Native Method)

 If anyone knows what I'm doing wrong or has a good tutorial on getting up and running it would be greatly appreciated.


P.S. I'm running MRL 1.0.107


7 years 12 months ago

Hello KevinM and Welcome !

OpenCV can sometimes be a pain...  So its important a simple set of steps be followed.  

First we are going to see if OpenCV native library works on your system.

Step 1 - find this file in your installation directory - ./libraries/jar/opencv-
Step 2 - unzip its contents into another directory - a jar file is just a zipped archive - the contents should look like the group of files below

when you exta

when you extract them all we want to make them executable
you can make files executable with the following command

chmod +x *

this usually turns the file green

Step 3 - this package was re-packaged with a neat little example program to attempt to start it type


This is the very basic low level native files of OpenCV - this example should start a window and attempt to connect to the first video device.  If it doesn't it "should" tell you a much more intelligent error why it can't run.

Good luck - let us know how it goes !

Okay I'm pretty sure I followed your directions correctly and I get this error

pi@raspberrypi ~/test/com/googlecode/javacv/cpp/linux-arm $ ./cpp-example-lkdemo
./cpp-example-lkdemo: error while loading shared libraries: libopencv_nonfree.so.2.4: cannot open shared object file: No such file or directory
I do see the libopencv_nonfree.so.2.4 file in the folder though 



I've installed MRL on a raspberry bananapi with raspbian, and before that work i had a similar problem, look here : http://myrobotlab.org/content/webcam-under-linux

To make it work i had to install lot of things and i don't know exactly what solved the problem .

In your error message, i see "libunicap2" so maybe, this part can solve your problem ...

sudo apt-get -y install libunicap2 libunicap2-dev

This is my post on the other webpage :

But, that work !! I don't know exactly what was missing, i've just installed a lot of thing after read this web page : https://ariandy1.wordpress.com/2013/02/13/raspberry-pi-rasbian-opencv/

I've done this part :

sudo apt-get -y install libpng12-0 libpng12-dev libpng++-dev libpng3
sudo apt-get -y install libpnglite-dev libpngwriter0-dev libpngwriter0c2
sudo apt-get -y install zlib1g-dbg zlib1g zlib1g-dev
sudo apt-get -y install libjasper-dev libjasper-runtime libjasper1
sudo apt-get -y install pngtools libtiff4-dev libtiff4 libtiffxx0c2 libtiff-tools
sudo apt-get -y install libjpeg8 libjpeg8-dev libjpeg8-dbg libjpeg-prog
sudo apt-get -y install libavcodec53 libavcodec-dev libavformat53 libavformat-dev libavutil51 libavutil-dev libswscale2 libswscale-dev
sudo apt-get -y install libgstreamer0.10-0-dbg libgstreamer0.10-0 libgstreamer0.10-dev
sudo apt-get -y install libxine1-ffmpeg libxine-dev libxine1-bin
sudo apt-get -y install libunicap2 libunicap2-dev
sudo apt-get -y install libdc1394-22-dev libdc1394-22 libdc1394-utils
sudo apt-get -y install swig

Hi, Iv got it work but I ended up doing a build/make on the raspberry Pi 2 took about 4hours but I can't find the post I used, I'll keep looking, 


7 years 12 months ago

Hey kevin, you mentioned you got opencv to work in myrobotlab on latest version of osx... Can you please explain which steps you followed ?? thanks a lot

Hey Alessandro sadly I don't remember the steps I took to install it and get it working seeing it's been awhile ago and the fact I don't really know what I'm doing lol.  As far as I remember I'm pretty sure I used Homebrew to install it (http://brew.sh) I don't remember what site I used for directions though


7 years 12 months ago

Yay! I got it up and running after doing a complete build.  It's a little slow but at least I have a video feed.  Thank you to everyone for your help.  Anyone know what this error might be?

- ERROR>> HIGHGUI ERROR: V4L: Property <unknown property string>(16) not supported by device
That's the only error that's popping up now