pan class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">copy</span><span class="p">()</span>
   <span class="k">del</span> <span class="n">fout</span><span class="o">.</span><span class="n">props</span><span class="p">[</span><span class="s1">&#39;FrameNumber&#39;</span><span class="p">]</span>
   <span class="k">return</span> <span class="n">fout</span>
<span class="o">...</span>
<span class="n">ModifyFrame</span><span class="p">(</span><span class="n">clip</span><span class=