Warner Bros: JumpSS to VTSM 0!

[r0lZ]

I have found a verry strange command in the DVD "The Fugitive", french, Zone 2 (Warner Bros):
[30 06 00 01 00 83 00 00] 80 (JumpSS) Jump to VTSM 0, Root menu (TTN 1)
Yes, it's really a jump to VTS 0!
And this line is repeated many times in various PGCs of the VTSM 1!

I have verified: thoses lines are executed when playing the DVD.
Someone could explain what a player is supposed to do in such situation?

[Dimmer]

That's apparently JumpSS FP (FirstPlay). Values 01 and 83 don't make any difference for the command but confuse IfoEdit.

[r0lZ]

Hi, Dimmer.

I'm not sure to understand you.
Byte 5 (upper nibble) is really what makes the difference between a jump to FP (should be 00), to VMGM Root menu (42), to VTSM X menu (8X) or to VMGM PGC (C0). No?

Do you mean that the fact that byte 4 is 00 automatically imply that it is a jump to FP, regardless of the value of byte 5? In this case, how to make the difference with JumpSS to VMGM PGC: byte 4 is 00 also!

I will burn some RW to check that on my Sony...
Anyway, thanks for the answer.

[Dimmer]

Yeah, I was probably wrong about the First Play link. Indeed, byte 5, its top 2 bits to be exact, makes difference between FP/VMGM/VTSM.

I tried to see what that command does in PowerDVD, and looks like VTS=0 preserves the value of SPRM5, meaning it goes to the root menu of the most recently played VTS. Scenarist doesn't allow VTS=0, which is a good indication that this is outside DVD standards. Check out what happens on a standalone Sony. I, too, find it a great way to test the DVD quality.

On the same topic, I've also been wondering what's supposed to happen if a CallSS command contains RSM=0.

[r0lZ]

Tests result (on my Sony player):

"JumpSS to VTSM 0, Root Menu" jumps to the Root Menu of the CURRENT VTSM.

In fact, this command react like a LinkPGCN in a VTSM, but link to a specific menu type, without the need to know the PGC number. This is great!

Now, I have to change the GUI in PgcEdit... :(

[r0lZ]

Cross posting!

You're right.

I will try to test RSM=0 also.

[r0lZ]

About the CallSS with resume cell = 0:
This means that the next resume must return to the point in playback where the CallSS was issued, no?
Or do I misunderstand your question?

[Dimmer]

Originally posted by r0lZ
About the CallSS with resume cell = 0:
This means that the next resume must return to the point in playback where the CallSS was issued, no?
Or do I misunderstand your question? Yes, that's what I meant to ask, but normally the current cell number is used in order to return to the same point. Again, Scenarist doesn't allow it to be set to 0. RSM=0 is probably the similar to the VTS=0 - the current cell number remains unchanged. My concern though is whether these commands are standard-compliant.

On the other hand, there is a perfectly legal command button=0 that works in a similar way.

[r0lZ]

The RSM=0 is perfectly working. I have already found this in numerous DVDs. But to be sure it is really legal, you have to pay around $5000 for the official specs! :devil:


I think that Warner Bros has paid for the specs, and therefore that the JumpSS with VTSM=0 is legal.


I have made another Sony test: putting a "JumpSS to VTSM 0, Root Menu" in a VMGM PGC work as expected: it jumps to the Root menu of the last visited title. (In my previous tests, I used the command in VTSM menus.)

So, as you already suspected, my assertion
"JumpSS to VTSM 0, Root Menu" jumps to the Root Menu of the CURRENT VTSM.
should be:
"JumpSS to VTSM 0, Root Menu" jumps to the Root Menu of the last visited VTS.


But I'm still in trouble with the SPRM 5:
VTS=0 preserves the value of SPRM5, meaning it goes to the root menu of the most recently played VTS
For me, SPRM 5 is not the VTS number, but the TTN number inside the VTS. And preserving it makes little sense if you actually specify the TTN parameter of the JumpSS command (byte 3).
Hence my questions: Is SPRM 5 really the TTN number? And, if so, how does the player know what is the last played VTS? I can't find any SPRM with this info. Or does it use SPRM 4 when the JumpSS command is in the FP or VMGM?
And, incidently, is it possible to set the TTN parameter (byte 3) to 0 too? With which effect?

[r0lZ]

I tried to see what that command does in PowerDVD
Is it a trick I missed in PowerDVD allowing to see the SPRM values?

[Dimmer]

You right, SPRM5 is not the right register. I guess I haven't been thinking clearly lately.

In fact, it looks like neither last played VTS number nor RSM cell number is available to us through SPRM. Maybe it doesn't keep VTS number anywhere but calculates it based on SPRM4.

The only trick with PowerDVD is that it displays current title (SPRM4) and PTT (SPRM7) even in menu mode. These two registers remain unchanged after CallSS to any menu in VTSM and VMGM domains until they are explicitly changed by a command like JumpTT.

I bet if you were to set TTN=0 in JumpSS command, it would preserve the original SPRM5 value, although I'm not sure what's the purpose of having this parameter there in the first place. Certainly, WB uses some high-end MAC-based software, which knows all the spec-compliant tricks including elusive seamless branching.

[r0lZ]

Tested JumpSS with TTN=0 on my Sony:

The player accept the command, but apparently set 0 in the SPRM 5 register. So, this doesn't work to preserve the SPRM 5 previous value.

The usage of the TTN parameter in JumpSS is still not verry clear for me...

[Zeul]

Seems i have the same command. So if i understand correctly, the command jumps to any of the 'named' pgc's (root, audio etc) without having to specify the actual PGC number, but is limited to the current VTS. As this isn't possible in scenarist are you replacing the command with a simple linkPGCN instead?

Zeul