title: invalid frame size while using ffmpeg
body: <p>I am trying scale and convert a video:</p>
  
  <pre><code>ffmpeg -i input.mkv -s 1920×1080 output.mp4
  </code></pre>
  
  <p>But every time it shows error (Windows):</p>
  
  <pre><code>Invalid frame size: 1920├ù1080.
  </code></pre>
  
  <p>or on Linux:</p>
  
  <pre><code>Invalid frame size: 1920×1080.
  </code></pre>