p>Default value is <code class="code">none</code>.
</p>
</dd>
<dt><samp class="option">filter_type</samp></dt>
<dd><p>For swr only, select resampling filter type. This only affects resampling
operations.
</p>
<p>It accepts the following values:
</p><dl class="table">
<dt>&lsquo;<samp class="samp">cubic</samp>&rsquo;</dt>
<dd><p>select cubic
</p></dd>
<dt>&lsquo;<samp class="samp">blackman_nuttall</samp>&rsquo;</dt>
<dd><p>select Blackman Nuttall windowed sinc
</p></dd>
<dt>&lsquo;<samp class="samp">kaiser</