title: Zbarcam-Raspberry Pi
body: <p>I am trying to get my webcam (connected to a Pi) to read qr codes. I was using zbar-tools for this but am currently getting the following error:</p>
  
  <pre><code>ERROR: zbar processor in zbar_processor_init():
  system error : spawning input thread : invalid argument (22)
  </code></pre>
  
  <p>Any ideas on what might be causing this error and how I can fix it?</p>