Adjust the antenna/LNB thoroughly. Use good quality cable, etc...
If there is no lock again, increase the antenna diameter.
Videos; chroma sampling 4;2;2 !
You use Lav filters codec or FFDShow codec
If key true
install K-Lite Codec Pack-the latest version and LAV Filters, while the screen is black, I'll see what happens during the match
unnecessary to install codec pack on PC. Because the codecs overlap each other.
Remove all codecs.
Clean with "Codec Tweak Tool" fix it.
Then, install only one codec.