title: subprocess.call on long standing process
body: <p>I'm using subprocess.call to run an external ffmpeg process that usually takes 1hr approx. What I see is that apparently after some time (for example 20min) my program is closed without returning from subprocess.call.</p>
  
  <p>Example:</p>
  
  <pre><code>import subprocess
  try:
    ret = subprocess.call(['ffmpeg', 'param1', 'param2', 'paramN'])
    print(ret)
  except:
    print("An exception has occured!") 
  </code></pre>
  
  <p>The <code>print</code> line is never reached.</p>