Can’t insert Set STN commands

[VRYK]

I wish to change a video’s default audio language. After First Play navigation moves to two PGCs (# 4 and 2) within the Video Manager domain (the only pre-commands being the respective Jump commands) before calling VMGM1 where the Main Menu is located. When I try to Paste before the command [51 00 00 81 80 00 00 00] in PGC4 or 2, PgcEdit indicates that this is not allowed. If this is so, am I obliged to introduce indirect SetSTN commands (there are none at present) ?

[r0lZ]

It's not the direct or indirect mode of the SetSTN command that is prohibited. You cannot use SetSTN in the VMG (First-Play PGC and VMGM). It's a (stupid) limitation of the DVD-Video standard. You must put the command in a VTST or VTSM PGC.

[VRYK]

Many thanks for the explanation.

I have created a new dummy PGC (# 4) in the Menu domain to add the relevant commands. However, all the JumpSS commands that I have checked out go from the VM domain to a specific Menu type (similarly all JumpTT commands navigate to numbered Title PGCs). Is there a further limitation here?

[r0lZ]

Yes. Again, it's a stupid limitation. You can jump to a menu PGC in the VTSM domains only if it is an "entry menu" (ie e menu that is also callable with the remote, such as RootM, AngleM...).

There are two possible workarounds:

1. Define your menu as an entry menu (right-click the PGC and select "Set Menu Type"), but take in mind that that menu will be also callable with the remote, so you may have to set a Prohibited User Operation in all title and menu non-dummy PGCs of the same VTS, to prohibit jumping to the PGC with the remote. (For example, if you have created a new AngleM entry menu, you should set the "Menu Call - Angle" PUO in all VTSM and VTST PGCs with playable content, in the same VTS. You don't need to set the PUO in the other VTSses, as there is no way to jump to a VTSM entry menu from another VTS.)
   
2. You can also set a free GPRM to 1, then jump to an existing entry menu PGC, and in that entry menu, check if the GPRM value is equal to 1. If it's the case, reset the free GPRM to 0 (so that the next time the menu is called your new commands will not be executed) and jump from the entry menu to your new dummy PGC. Otherwise, execute the original pre-commands of the entry menu PGC.
   For example, if GPRM 15 is free (you can check the free GPRMs with Info -> GPRMs), and your new dummy PGC is PGC #99, then you should use something like this:
   • In your VMGM menu, set GPRM 15 = 1, then jump to, say, the RootM of the target VTSM.
     
   • In the RootM of the target VTSM, insert something like this at the beginning of the pre-commands area:
     

     [00 B1 00 0F 00 01 00 04]   1  if ( gprm(15) != 1 ) then { Goto line 4 } 
     [71 00 00 0F 00 00 00 00]   2  Set gprm(15) =(mov) 0 
     [20 04 00 00 00 00 00 63]   3  LinkPGCN PGC 99 
     [00 00 00 00 00 00 00 00]   4  NOP 
     (original pre-commands here)

[VRYK]

Thanks very much for the explanation and code. I chose the second option and all's well.