e> options or using the <samp class="file">libavutil/opt.h</samp> API for
programmatic use.
</p>
<dl class="table">
<dt><samp class="option">uchl, used_chlayout</samp></dt>
<dd><p>Set used input channel layout. Default is unset. This option is
only used for special remapping.
</p>
</dd>
<dt><samp class="option">isr, in_sample_rate</samp></dt>
<dd><p>Set the input sample rate. Default value is 0.
</p>
</dd>
<dt><samp class="option">osr, out_sample_rate</samp></dt>
<dd><p>Set the output sample rate. Default v