title: How to make ffmpeg insert timestamp in filename
body: <p>I'm trying to make a bash script that grabs a still shot from an IP camera and than emails it.</p>
  <p>Using</p>
  <pre><code>ffmpeg -i http://admin:Stupidpassword1@10.12.10.40/Streaming/channels/1/picture \
    -f image2 -updatefirst 1 doorbell.jpg 
  </code></pre>
  <p>From what I have read this should work but the output file name is still <code>doorbell.jpg</code> How can I make the filename <code>TIMESTAMPdoorbell.jpg</code>?</p>