VMGM post won't allow jump vmgm menu;
It seems that it is impossible to have the VMGM menu loop without resorting to ugly hacks: inside the <pgc> for the <vmgm>'s <menus>, I put <post>jump vmgm menu;</post> but dvdauthor just spits out
ERR: Cannot find PGC with entry
ERR: in VMGM pgc 0, <post>
It's not a big deal, because I've worked around it by jumping to the titleset menu, which then jumps again to the VMGM by default.
Hi. Sorry for the delay in responding to this.
Looking at the allowed instructions, it appears that “JumpSS VMGM Menu” is not allowed within the VMGM. So your workaround—“JumpSS VTSM” followed by “JumpSS VMGM Menu”—looks reasonable.
Another option might be “JumpSS VMGM PGC”, which is allowed in the VMGM.
I must admit it’s been a long while since I looked at all the details of what is and isn’t allowed.