title: How to get the current frame number in AviSynth?
body: <p>In AviSynth, is there a function that returns the current frame number? If not, how can I get the current frame number?</p>
  
  <p>That's my question, but for quality standards:<br />
  The goal is the use it in a conditional statement so it's clear what one is looking at when comparing an encode to its source. Something like the following.</p>
  
  <pre><code>a=import("source.avs")
  b=ffvideosource("encode.mkv")
  interleave(a,b)
  media = ((currentFrame % 2 &gt; 0) ? "Encode" : "Source")
  subtitle(media)
  </code></pre>