p:inline 004

The pipeline

<p:declare-step xmlns:c="http://www.w3.org/ns/xproc-step"
                xmlns:err="http://www.w3.org/ns/xproc-error" xmlns:p="http://www.w3.org/ns/xproc"
                xmlns:t="http://xproc.org/ns/testsuite/3.0" name="main" version="3.0">
   <p:output port="result" sequence="true"/>
   <p:identity name="inline">
      <p:with-input port="source">
         <p:inline encoding="unknown"
                   content-type="image/png">
iVBORw0KGgoAAAANSUhEUgAAAIAAAAAdCAYAAABixmRWAAAABGdBTUEAALGPC/xhBQAAACBjSFJN
      </p:inline>
      </p:with-input>
   </p:identity>
   <p:cast-content-type name="cast"
                        content-type="application/xml">
      <p:with-input port="source" pipe="@inline"/>
   </p:cast-content-type>
   <p:wrap-sequence wrapper="c:result"/>
</p:declare-step>