title: Too many inputs specified for the "split" filter
body: <p>I just tried to stitch 2 files and tried to get multiple outputs parallely:</p>
  
  <pre><code>ffmpeg -i 1.mp4 -i 2.mp4 -filter_complex "[0:v:0] [0:a:0] [1:v:0] [1:a:0] concat=n=2:v=1:a=1, split=2[out1][out2]" -map '[out1]' -preset ultrafast -vn -b:a 128k -c:a aac  tes45.mp4 -map '[out2]' -preset ultrafast -vn -b:a 128k -c:a aac  tes46.mp4
  </code></pre>
  
  <p>But it didn't work:</p>
  
  <pre><code>Too many inputs specified for the "split" filter.
  Error initializing complex filters.
  Invalid argument
  </code></pre>