A dummy question about dummy PGCs!

[CoNS]

Why are there sometimes dummy PGCs in Menus and Titles of a VTS?

When I blank out a PGC using VobBlanker, or all titles in a VTS using VobBlanker, PgcEdit or TitleSetBlanker, I can see that PgcEdit counts the newly blanked PGC(s) as dummy PGC when I reload the disc. This I can understand.

But also, retail DVDs seem to be "born" with dummy PGCs? For instance, I have a retail DVD9 (The Beach, PAL), which I copied to my harddisk and then loaded into PgcEdit without doing any blanking. I can see in the PgcEdit that for example the VMGM has 46 PGCs, where only no. 2 and 46 are "real" PGCs with a content. The rest are listed as dummy PGCs...?! Also in VTSM 1 there are several dummy PGCs and so on.

Why oh why is that? What do they do and why are they there? :)

[lark]

you need PGCs for different kind of DVD navigation: setting registers and jumping based on settings. a dummy PGC is just a PGC w/o any streams (video, audio, ...). why would you have a video attached to a PGC that is e.g. used only to set a register and jump somewhere else?

regards
t :)

[CoNS]

Ok, yes, I can see in PgcEdit that the dummy PGCs contain pre commands etc.

So the definition of a dummy PGC is simply that it doesn't contain video, audio or subtitle streams?

[blutach]

@cons

Yes, that's right. No video or audio.

It's something new that they are appearing in the VTS domain, as the DVD spec says they can't be there. However, it has been proved that they work and we are seeing more DVDs with dummy PGCs in the VTS domain.

Regards

[2COOL]

Speaking of the DVD Specs...I've been told that in our menus, the Next Chapter and Go Up (return) buttons can be specified and configured but you can't do the same for the Previous button.

[r0lZ]

Originally posted by 2COOL
Speaking of the DVD Specs...I've been told that in our menus, the Next Chapter and Go Up (return) buttons can be specified and configured but you can't do the same for the Previous button. I've heard the same thing. But the Prev chapter button works in menu on my Sony!
Anyway, the DVD Specs are bullshit. IMHO, the real, useful standard is established by the ability of the players to do things or not.

[jeanl]

Originally posted by r0lZ
I've heard the same thing. But the Prev chapter button works in menu on my Sony!
Anyway, the DVD Specs are bullshit. IMHO, the real, useful standard is established by the ability of the players to do things or not.
well then, since not all players behave the same way in contorted cases (see for example your still time tests), we're up the creek!!!!
Jeanl

[blutach]

@jeanl

That's why I play to test on all my players.

BTW: Nice upgraded guide (I noticed no-one answered your post, but that didn't mean it's not appreciated - at least by me :))

[2COOL]

Originally posted by r0lZ
Anyway, the DVD Specs are bullshit.Why rely too much on the DVD specs and for good reasons. We always need some reference to fall back on when logic is concerned, even though none of us got the real specs in front of us.

According to the DVD FAQ (http://www.dvddemystified.com/dvdfaq.html), here's the rundown on getting them.
The official DVD specification books are available after signing a nondisclosure agreement and paying a $5,000 fee. One book is included in the initial fee; additional books are $500 each. Manufacture of DVD products and use of the DVD logo for non-promotional purposes requires additional format and logo licenses, for a one-time fee of $10,000 per format, minus $5,000 if they already paid for the specification. (E.g., a DVD-Video player manufacturer must license DVD-ROM and DVD-Video for $20,000, or $15,000 if they have the spec.) Contact DVD Format/Logo Licensing Corporation (DVD FLLC), Shiba Shimizu Building 5F, Shiba-daimon 2-3-11, Minato-ku, Tokyo 105-0012, tel: +81-3-5777-2881, fax: +81-3-5777-2882. Before April 14, 2000, logo/format licensing was administered by Toshiba.

Anyways, for the most part, we rely on our experience and hearsay from credible sources. Only experienced people who have dabbled in DVD structure long enough and without the books will dare to challenge the specs. It's so frustrating to say to others on a certain taboo thing and later find out that what is considered not supposed to happen IS really happening in front of your eyes. I think the specs got lost in english translation since I assume that it started off in Japanese. It all comes down to the DVD manufacturers (software or hardware) whether they follow strictly to the specs or let a few functions slide by.

I agree with you r0lZ...the specs SUCK! :angry:

[blutach]

We are a bit OT here (so sorry for prolonging the convo), but I'm just waiting for the day when set top players get smart and recognize files instead of sectors. It will be the end of Get VTS Sectors (sorry Derrow) but, more importantly, the end of crummy burns due to Nero's "packing em in" strategy (although I have yet to have a real problem with this).

Regards to all

[2COOL]

Sorry to having this thread going OT but I saw a window of opportunity to express my thoughts. ;) enough said in this thread.

[jeanl]

Originally posted by blutach
@jeanl
BTW: Nice upgraded guide (I noticed no-one answered your post, but that didn't mean it's not appreciated - at least by me :))
Thanks man! I still check the counter on the page, that's rewarding in itself! Besides, no comments means people don't have any problem with the guide right? :)
Jeanl

[CoNS]

Now I'm OT'ing my own thread, too, but I'd like to thank you aswell jeanl for your guides. They are extremely useful, just like 2COOL's guides are. KUTGW both of ya! :)

[jeanl]

Thanks a bunch CoNS! I appreciate the comments!
2COOL's the man though!!!
Jeanl

[2COOL]

Originally posted by jeanl
Thanks a bunch CoNS! I appreciate the comments!
2COOL's the man though!!!Awwww...you're making me blush. :o