rd</samp>&rsquo;</dt>
<dd><p>Set the standard. Must be the name of a supported standard. To get a
list of the supported standards, use the &lsquo;<samp>list_standards</samp>&rsquo;
option.
</p>
</dd>
<dt>&lsquo;<samp>channel</samp>&rsquo;</dt>
<dd><p>Set the input channel number. Default to -1, which means using the
previously selected channel.
</p>
</dd>
<dt>&lsquo;<samp>video_size</samp>&rsquo;</dt>
<dd><p>Set the video frame size. The argument must be a string in the form
<var>WIDTH</var>x<var>HEIGHT</va