static opencv cannot find USB webcam on arm Linux busybox?

Question

I have a small busybox system for which I compiled the kernel and added support for USB cameras. When when I connect the camera to the device it gives me some output and I get a /dev/video0 device:

usb 1-1: new high-speed USB device number 3 using orion-ehci
uvcvideo: Found UVC 1.00 device Webcam C170 (046d:082b)
input: Webcam C170 as /devices/platform/orion-ehci.0/usb1/1-1/1-1:1.0/input/input1

/ # ls -l /dev/video0
crw-rw----    1 0        0          81,   0 Mar  8 08:08 /dev/video0
/ # 

I have statically compiled opencv2.4 for arm with all needed libs and get no error compiling the code:

Mat frame;
VideoCapture capture(0);
if(!capture.isOpened()){
    printf("Cannot open camera\r\n");
    printf("%s\r\n", cvErrorStr(cvGetErrStatus()));
}

which gives me as output:

Cannot open camera
No Error
/ # 

The camera works fine on my laptop and I have tried multiple camera's all with the same result. I have also tried many different ways of opening the camera trough opencv which also gave me the same results.

How can I get my busybox system and opencv to read from the camera?

Answer 1

You might be missing V4L. I would run the sample code for V4L and investigate that. Did you check with ldd that you have all the libraries you program is linked against?