title: Does OpenCV support v4l2?
body: <p>I'm writing a Python program using OpenCV, but I cannot capture images from v4l2 cameras.</p>
  
  <p>I tried with both a PS2 EyeToy and Droidcam (Android virtual webcam), which are both using v4l2, and none of them work: cv.CaptureFromCAM(0) only returns None.</p>
  
  <p>I can use both webcams in other programs (tried VLC and Kamerka).</p>
  
  <p>I guess that OpenCV supports v4l only, not v4l2.</p>
  
  <p>How can I solve this problem? Does a v4l2->v4l converter exist?</p>
  
  <p>EDIT: I read that cv.CaptureFromFile uses ffmpeg to decode video files. Is it possible to manually specify a format, so I can use ffmpeg's <code>video4linux2</code> demuxer?</p>