OK, I think I figured it out with a little help...
Make sure you have a 1280x720 jpeg. Example: mypicture.jpg.
$ ffmpeg -i mypicture.jpg -r 25 -b 20000 -s hd720 mypicture.m1v
$ mv mypicture.m1v mypicture.mvi
FTP up to box on /media/hdd/bootlogos and fire up the logomanager...
That really works great , can setup a batch file.
thanks
BTW, the new openpli (or multiboot) puts in /boot a link to directory /usr/share/bootlogo.mvi