title: Using ffmpeg library with Qt framework results in error
body: <p>When I include:</p>
  
  <pre><code>extern "C" {
  #include &lt;libavcodec/avcodec.h&gt;
  }
  </code></pre>
  
  <p>I am getting the error:  </p>
  
  <blockquote>
    <p>undefined reference to QVideoSurfaceFormat::QVideoSurfaceFormat(QSize
    const&amp;, QVideoFrame::AVPixelFormat, QAbstractVideoBuffer::HandleType)</p>
  </blockquote>
  
  <p>without the include - build success.</p>
  
  <p>My guess that include brings some defines that breaks QVideoSurfaceFormat defenition.<br>
  Have someone faced with the similar issue?</p>