Video to show it in action

There were a few challenges to overcome. You can’t launch ffplay directly from PowerShell, it must be launched from a cmd window (I gave up trying but it might still be possible). You can’t run ffplay with its -fs (full screen) switch because PowerShell keeps jumping on top of the player. I tried all sorts of tricks to try an minimize and resize windows. In the end I had to go with some code to switch the ffplay window to maximize.


  • MS Surface (I’m just using an i5)
  • USB 3 capture device (Elgato Cam Link in this demo, I also have use Ultrastudio)
  • HDMI Multiview output from ATEM
  • Ffplay (comes with ffmpeg)
  • .cmd file to launch ffplay
  • PowerShell.exe script (link below)
  • Switcherlib.dll to interface between PowerShell and the ATEM!ApGpqMMpRLhikJVpf1M_JytL0tI7vQ


Place .ps1 script, switcherlib.dll and ffplay in same directory (right click on each file and check properties for un-block option)

Create shortcut on desktop to PowerShell with the following command and set the “Start In” location to match where you have saved the files.
C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -command “& c:\tools\scripts\atem_multiview.ps1”



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