Muxman: keeping track of chapter changes in the menu

[simon72]

Hello,
I'm using Gui For DVDAuthor (with Muxman as muxing engine) to create audio compilations; in the titleset menu I'd like to update the highlighted button according to the current track whenever the user returns to the VTS menu.

I have a few questions that most probably somebody skilled in Muxman can answer quite easily:
a) using the cell command in the Muxman script I can specify an action; in my case I set a GPRM to store the track number for updating the menu; unfortunately, the action seems to be triggered only when the cell finishes, so if the user skip track using the remote the current track number is not updated; is there a solution, such as a "pre" command similar to what is available in a menu?
b) does adding a cell command for every track (which is simply a Mov of a direct value into a GPRM register) break the seamless playing? I'm doing mostly concerts, so most of the times I do not want to hear a gap between chapters;
c) what is the limit to the number of lines of code (number of instructions) in the pre/post section of a menu? I heard there is a limit, but I can't find what is it. The problem is connected to the same issue I'm trying to solve, because when I select a track I store the track number in the GPRM and then jump to the corresponding title/chapter, and this cannot be done as a single command associated to the menu - so I create a series of if/jumps in the Post section of the menu; does it make any difference using longer or shorter labels for the GoTo instruction?

Thank you!

[blutach]

First, this editing is easiest to do with PgcEdit (no need to remux).

There is no need to set a cell command for every track (and yes, that would make each cell non-seamless). When you press menu, save the title and chapter number in a register. Push the title number, multiply it by 256 and or the chapter number (or if there's only one title, just push the chapter number). Then test the chapter number and go to the correct program, PGC or whatever, selecting the correct button number in the process.

But even easier is to use wencaS's chapter commands program (see here). This puts all the right commands in the chapter menu for you (it is implicit that you are using PgcEdit).

And finally, there is a maximum 128 commands per PGC.

Regards

[simon72]

Thank you for your reply, Blutach.

What I would like to achieve is highlighting the button in the menu corresponding to the chapter that was playing when the user pressed the menu button on the remote. Let's say we have a VTS1 with 10 chapters; the user selects the 1st chapter; the music starts playing. At chapter #3, the user presses Menu on the remote; I would like to return him to the menu with the 3rd chapter button highlighted. By using the cell command I can update a GPRM and use it upon return; this strategy works if the user does not push next/previous track buttons, because the cell command is executed only when the cell/chapter ends and that's the reason why I was studying different strategies. The fact that the program becomes non-seamless makes my method less appealing, for the reason I already mentioned in my first post. In your experience, have you ever tried burning a DVD with (Mov GPRMx, y) as cell commands in a context where a discontinuity would be easily detected? I'm just wondering, because it seems to me that copying a value to a register should not be such a great burden on the DVD microcontroller to cause a gap in the reproduction...

How does the rule "128 commands per PGC" applies to menu? You mean the commands in both Pre and Post menu (the sum of these commands)?

Regards,
Simon

[blutach]

128 total in pre, post and cell commands.

The procedure I outlined in post 2 gets you to exactly you want to be. No need for cell commands and therefore seamless playback is retained.

Having a cell command means the cell must be non-seamless. This is a standard. The player stops, executes the command and does what it's told. It's as good as going out of the PGC.

Regards