I've tried several things on the first glyphs found, including rotating them 180°. Using the regular alphabet I just get out
:
NM OU WSQOCDIB SNM YO? GD TMQADIS <-- regular
WIHEMQY HC YKU MNW FNHGKMWSYKMN <-- 180°
Perhaps the morse and mud languages have to be Vigenèred? They're roughly the same lenght, if we exclude a couple of non existing glyphs from the mud. Maybe the answer is in the pigpen, but I can't seem to find them in the original video so far, I'll just recheck every frame again. I should probably use a frame difference mask though, but never attempted such a thing.