====== Desktop output to SDI blackmagic ======


https://stackoverflow.com/questions/25396784/how-to-record-a-specific-window-using-ffmpeg

https://forum.blackmagicdesign.com/viewtopic.php?f=3&t=11840

playout on decklink:
ian morrishs code adapted:
ffmpeg -i v:/blackmagic/atem/in/test.avi -f decklink -pix_fmt uyvy422 "DeckLink SDI 4K"