>channels</samp>&rsquo;</dt>
<dd><p>Set the number of channels. Default is 2.
</p>
</dd>
</dl>

<a name="lavfi"></a>
<h2 class="section"><a href="ffmpeg-devices.html#toc-lavfi">3.13 lavfi</a></h2>

<p>Libavfilter input virtual device.
</p>
<p>This input device reads data from the open output pads of a libavfilter
filtergraph.
</p>
<p>For each filtergraph open output, the input device will create a
corresponding stream which is mapped to the generated output. Currently
only video data is supported. The filte