Hi everybody ,

I've got a little problem : My webcams work under raspbian with guvcview, but not in MRL . I've tried few camera index in opencv tab and i've also tried to choose "file" with the link /dev/video1 .

I'm using raspbian weezy on a raspberry banana pi .

someone use webcam with MRL under linux ?

thx for your help


8 years 8 months ago

Ciao beetle.. Probably the problem has to do with opencv dependencies... Send a noworky after you hit capture with index 0 or 1

try installing this libraries, maybe OpenCV is happy but can't show the video correctly : 

sudo apt-get -y install x264 v4l-utils ffmpeg


installing libopencd-dev, didn't solved the problem :-(

I'll test with an other webcam, i hope it's not that, i don't want to change the eyes au my robot lol !

Hi Beetlejuice !

Step 1 ->  get OpenCV working first .. before trying to use through MRL...
I don't remember but I think their might be a LKDemo executable in the opencv jar .. extract it .. try it ..

The nice thing about trying to get lkdemo to work first is when it does not work it usually tells you the problem..

Thx Grog, but when i clic on lkdemo, nothing happen ... Even after make the file executable .

But, that wor k !! 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 , it work but slowly .

The video hardware acceleration driver was missing . It is build and installed now .

I get a framerate around 24,5 fps with guvcviewer (color, 640*480) but still 5fps with openCV in MRL (pyramidDown and gray ) , 2 fps in color , and 0/1 fps in color 640*480 ...

I didn't success to run lkdemo take in opencv.jar . I must do someting wrong .