title: Convert embedded SVG to PNG in-place
body: <p>I'm generating HTML from a Docbook source while using SVG for images (converted from MathML). This works fine for some browsers that can interpret SVG, but fails for others.</p>
  
  <p>What I would really like is to add a post-processing step that will convert SVG to PNG "in-place" (within the HTML).</p>
  
  <p>So something like this:</p>
  
  <pre><code>&lt;body&gt;
      &lt;svg xmlns="http://www.w3.org/2000/svg" version="1.1"&gt;
          &lt;circle cx="50" cy="50" r="30" /&gt;
      &lt;/svg&gt;
  &lt;/body&gt;
  </code></pre>
  
  <p>Would get seamlessly converted to this:</p>
  
  <pre><code>&lt;body&gt;
      &lt;img src="img0001.png" /&gt;
  &lt;/body&gt;
  </code></pre>
  
  <p>And I would get a converted PNG alongside.</p>
  
  <p>Is there something that will do this?</p>