add video enconding

[veso266]

Hi I tried your PALMod project and it works great (exept picture is a bit shaky and I don't know why I am using a bit modified grc flowgraph to transmitt it: http://downloads.dxing.si/pal/pal.grc) and I wonder if you could add .yuv video encoding to it (here is a ntsc one maybe it can be modified to work with pal: https://github.com/argilo/sdr-examples/blob/master/ntsc/ntsc-encode-yuv.py)

and for some reason if i use python3 on linux it generates difrent result then python2.7 on windows (I thought its a EOL problem but when I saw that your are opening files in binary mode (with open("uv.out", "wb") as f:) that should not metter so I don't know where the problem is
here a the files for comparison
linuc version: http://downloads.dxing.si/?dir=pal/linux
windows version: http://downloads.dxing.si/?dir=pal/windows

Thanks for Anwsering and Best Regards

PS: do you know any python test-card generator (would like to create something like this: https://www.youtube.com/watch?v=KUenRyt5u5Y )