title: Variable audio data length for a .wmv file in DirectShow
body: <p>I have a question for the guru of WMV formats. I found one WMV file that is handled differently than other WMV files in DirectShow. The length of its data packets varies. This does not affect playback, but it does affect my application. So my question: is it ok for WMV video format or this file is corrupt?</p>
  <p>You can reproduce this situation using the following:</p>
  <ol>
  <li>GraphStudio - DirectShow utility.</li>
  <li>LAV filters - <a href="https://github.com/Nevcairiel/LAVFilters/releases" rel="nofollow noreferrer">link</a></li>
  <li>That WMV file - <a href="https://kvycambgr.com/files/Wildlife.zip" rel="nofollow noreferrer">link for downloading</a></li>
  <li>How to assemble a graph:
  <a href="https://i.stack.imgur.com/9ielR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9ielR.png" alt="enter image description here" /></a></li>
  </ol>
  <p>So far, I see a solution to this issue in an additional audio filter to equalize the length of the data. But I'm afraid that it will add an extra delay in the sync of the audio and video.</p>
  <p>Thank you.</p>