Получить картинку через OpenCV, cvCaptureFromCAM (Logitech QuickCam Express)

$ lsusb
Bus 005 Device 002: ID 046d:0928 Logitech, Inc. QuickCam Express

$ lsmod | grep gspca
gspca_spca561           8512  0 
gspca_main             18727  1 gspca_spca561
videodev               29993  1 gspca_main
usbcore               122034  8 usb_storage,gspca_spca561,gspca_main,usbhid,ohci_hcd,xhci,ehci_hcd

capture.cpp :
#include <stdlib.h>
#include <stdio.h>
#include <opencv/cv.h>
#include <opencv/highgui.h>

int main (int argc, char **argv) {
  if (argc < 2) return -1;
  char *filename_o = argv[1];
  CvCapture *capture = cvCaptureFromCAM(CV_CAP_ANY);
  if(!capture) perror((char*)"No Capture");
  IplImage *img=cvQueryFrame(capture);
  cvSaveImage(filename_o, img);
}