title: Display libavcodec log
body: <p>I'm currently playing with libavcodec as a static library, and I would like to get the debug message (printed by the following)                </p>
  
  <pre><code>av_log(h-&gt;avctx, AV_LOG_DEBUG,
                     "NAL_IDR Detected\n");
  </code></pre>
  
  <p>Only the message printed with </p>
  
  <pre><code>av_log(h-&gt;avctx, AV_LOG_ERROR,
                     "NAL_IDR Detected\n");
  </code></pre>
  
  <p>are currently displayed. Does anyone know how to activate this ? I see a DEBUGLEVEL option in the configure script, but no further description is given.</p>
  
  <p>Regards,</p>
  
  <p>Nicolas</p>