title: FFmpeg command for crossfading between 5 videos .How to manage setpts=PTS-STARTPTS?
body: <p>Here, New in FFmpeg . I am using and testing in console in FFmpeg .</p>
  
  <blockquote>
    <p><strong>I already done with 2 video join with cross fading with this question  :
     I am doing for 5 videos merging with cross fade  I just done 90%  in  merging 
    i just need to manage setpts=PTS-STARTPTS Just look into this pls.</strong></p>
  </blockquote>
  
  <pre><code>ffmpeg -i big_buck.mp4 -i big_buck.mp4 -i big_buck.mp4 -i big_buck.mp4 -i 
  big_buck.mp4 -filter_complex "[0:v]trim=0:4,setpts=PTS-
  STARTPTS,fade=out:st=4:d=1:alpha=1[1]; [1:v]trim=1:4,setpts=PTS-
  STARTPTS,format=yuva420p,fade=in:st=0:d=1:alpha=1,fade=out:st=4:d=1:alpha=1[2]; 
  [2:v]trim=1:4,setpts=PTS-
  STARTPTS,format=yuva420p,fade=in:st=0:d=1:alpha=1,fade=out:st=4:d=1:alpha=1[3]; 
  [3:v]trim=1:4,setpts=PTS-
  STARTPTS,format=yuva420p,fade=in:st=0:d=1:alpha=1,fade=out:st=4:d=1:alpha=1[4]; 
  [4:v]trim=1:4,setpts=PTS-STARTPTS,format=yuva420p,fade=in:st=0:d=1:alpha=1[5]; 
  [1][2]overlay,format=yuv420p[12]; [12][3]overlay,format=yuv420p[123]; [4]
  [5]overlay,format=yuv420p[45]; [123][45]concat=n=2 [v]" -map [v]  result.mp4
  </code></pre>
  
  <p>****Note that every input video big_buck.mp4 length is 5 sec ****. now see <strong>setpts=PTS-STARTPTS</strong>  in code   How to Manage that in every video Input????  </p>
  
  <p>I also see in variuos forums about that but i didnt find!!!
  Thank you </p>