'Next Chapter' button jumps to next title

[Dr.Khron]

I have a home made DVD with 4 titles. If you press the "Next Chapter" button on the remote for my stand alone player while watching the last chapter of a title, it will jump to the first chapter of the next title.

i would rather that it execute the post commands, just like it does when the last chapter finishes playing. This way, it will jump back to the main menu.

Is there any way to control this behavior? Maybe with a flag or something?

Whats wierd is that this behaves differently in different players...
In my stand alone hardware player and in media player classic, the next chapter button jumps to the next title.
In PgcEdit Trace mode, the next chapter button does nothing.
In PowerDVD, the next chapter button jumps you back to the main menu (I don't know if its executing the post commands or not, but this is the behavior I want)

[r0lZ]

Normally, when you press the next chapter button when the last program of a PGC is playing, the sequence of operations is:

The player should check the PUOs, and do nothing if the Next PG PUO is enabled in the IFO or the VOB.
Similarly, the player should check the cell type flags, and do nothing if the Access Restricted flag is on.
Otherwise, it should check the NextPGCN link, and jump to that PGC if it is greater than 0. (See notes below.)
Otherwise, it should either do nothing, or jump to the post commands. (I don't know what is supposed to be the standard behaviour.)

I have cloned the behaviour of my Sony in PgcEdit. It does nothing if the NextPGCN link is 0.

Notes:
The Next Chapter button jumps to the next Program, not the next Chapter! (Not really important for your problem, but that means that you can use it in the menu domains)
The cell command of the current cell is ignored when you press Next PG.
The NextPGCN link (as well as the PrevPGCN and GoUpPGCN links) is only valid in a menu domain, or in a not-one_sequential title. Therefore, in the Title Domain, the link must point to a PGC belonging to the same TTN.
The NextPGCN link can point to itself. In this case, the post-commands are executed!
However, it is still uncertain if a NextPGCN link pointing to itself can be defined in a one_sequential file. Since it points to itself, it points to the same TTN, and, IMO, that's OK. But some players (notably PowerDVD) assumes in this case that the title is not-one_sequential, and doesn't allow to jump to a specific time in the Title. (That's a limitation of true not-one_sequential titles.)

As you can see, the answer to your problem might be in the last note. Try to set the NextPGCN link to point to the same PGC. (So, if your Title is PGC 1 of the domain, set it to 1.) It might do what you want, but, as explained in the note, you might be unable to use the time bar in PowerDVD, and maybe also the "Jump To" function of your standalone.

Note that you can also use the "Enable All Operations" function on the PGC. That macro removes the PUOs and Access Restricted Flags, and sets the Prev and NextPGCN links to point to itself (if they are zero).
(Some players need the PrevPGCN link to accept to jump back to the beginning of the title when you press Prev Chapter during the playback of the first program.)

If that trick doesn't work, use the method that is found on many commercial DVDs: add a tiny black cell at the end of the title, and assign it a new Program number. (Usually, a new chapter number is also added to that program, but IMO that's not necessary.) This way, when you will press the Next Chapter button during the playback of the real last chapter, the playback will jump to the dummy last chapter, and execute the post commands 1/2 second later.
(Do NOT add a chapter number on true not-one_sequential files, spread over several PGCs!)

Of course, if the post-commands are authored to jump to the next Title, none of those tricks will work. In this case, you have to reauthor them to return to the menu.

[Dr.Khron]

Wow, a thorough and useful response. Thank you very much.

[Dr.Khron]

Ah, so THATS what those little blank cells are for! I always wondered that. Thats the solution I like the best, I think I'll go with that one. Adding these cells brought up some new questions.

Question about adding cells with PgcEdit:
When adding a blank cell, PgcEdit automatically gives the new cell the 2 flag: "STC (SCR) discontinuity". This also flags the "layer break" check box.

I've noticed that on a commercial DVD, the first cell, and sometimes the last cell, have the 2 flag. All other cells have the 8 flag: "seamless playback joint".

Question 1:
Which joint does this refer to, the begining or end of the cell?

Question 2:
What does making the last cell in a PGC a flag 2 do? how is this different from having flag 8?

Question 3:
What does the layer break check box do? Why is it greyed-out sometimes?

[r0lZ]

STC discontinuity means that the "System Time Clock" (something similar to time codes) is reset at the beginning of the cell. Since the new cell is not contiguous to the previous one or has a new VOB ID, this flag must be set. It must, of course, also be set on the first cell, since the clock must be reset when you enter the PGC. It has no visible effect from the user point of view.

The "seamless joint" flag indicates that the cell must be played seamlessly (without a little pause) with the previous one. So, the joint refers to the link between the prev and current cells.
This flag has to be clear on the layer break cell, or if the previous cell has a cell still time or a cell command. It must also be clear on the first cell, since there is no previous cell to play seamlessly.
Since the new cell is added without particular care at the end of the VOB files, it is safer to set this flag (although it might be useless in some cases). Anyway, if the last image of the last original cell is black, you will not notice the pause. IMO, it is better to leave it in place, or your standalone player might freeze. This flag has usually no visible effect when you play the DVD on a PC.

Forget the Layer Break flag. It is exactly the inverse of the seamless joint flag, and has been introduced for historical reasons. I have replaced it with the seamless flag in PgcEdit v8. (Therefore, in V8, all chackboxes are inverted, and a chackbox that is clear near the middle of the movie can be the layer break position.)

See this post (http://forum.doom9.org/showthread.php?p=844110#post844110) for more info about the pseudo "layer break" flag.

[r0lZ]

BTW, I forgot to say that if you need to insert several tiny cells in the same domain (for example if there are several titles in the VTS) you can re-use the same tiny cell. Use Pick an existing Vob/Cell ID and click on the Use last blank cell in VOB button to retrieve the correct V/CID. This button is unavailable if PgcEdit cannot detect a blank cell at the end of the VOB.

[Dr.Khron]

Ahh, much clearer now, thank you...

One question I still have, tho.
What (if any) advantage is there to having the LAST cell in a PGC flagged with #2 "STC (SCR) discontinuity"?
(some commercial DVDs have this)

Since the joint in question is from the PREVIOUS cell, it seems sort of useless to put that flag on the last cell.

[r0lZ]

The tiny cell is often a separate VOB (Video OBject - see note below). It's also the case with the tiny cell added by PgcEdit.

By definition, a VOB must have a STC starting at 0. When the VOB ID changes, you enter a new VOB, and therefore the STC discontinuity flag must be set.

Note: I use here the word VOB to designate the Video Object made of one or several VOB cells with the same VOB ID (but different Cell IDs.) It's not a VOB file! Unfortunately, the DVD-Video terminology is sometimes very confusing!

[Dr.Khron]

Oh yeah, I sometimes get confused about difference between VOB and VOB.

So, I'm adding new blank cells to ends of my titles, and I get an error on one of them. (the rest worked just fine)

"Error appending new Cell to VOB file:

The number of sectors in the VOB file(s) (1788341 sectors) don't match the VTS_C_ADT table (1788336 sectors)!"


Any way I can fix this so that I can add the blank cell?

[r0lZ]

Try to process the domain with FixVTS. Should work.

[Dr.Khron]

And it did!

Thanks again, man.