I hope someone can help me
First of all, my components are :
Asus Sabertooth P67
Intel i5 2500k
Ati Radeon RX580 Nitro+
SMBios : iMacPro1,1
Everything works perfectly on Monteray and BigSur, except h264 rendering ... VideoProc (everything is green and supported) , Davinci resolve, FCPX, Mediaencoder... every single program freeze and then restart the computerwhen try to render anything in h264. H265 working perfectly.
I tried to change smbios, tried iMacPro1,1 , MacPro6,1 and 7,1, same thing.
Tried several bootflags in bootloader, and nothingworks
Just to say, OPencore is on the latest version, as all the kexts.
I hope someone have some idea how to resolve this.