Incredibly weird PGC Strucutre, or Possible Bug (IFOEdit/DVDDecryptor)

[Chu]

Hello all. I've been messing around with "the big 3" for reauthoring DVD's, and I have come across a DVD that either is using some feature of DVD's that I do not know about, or there is a bug in DVDDecryptor and IFOEdit. I am hoping you can help me decipher this.

The DVD in question is an Anime DVD (Noir, vol. 4), with 4 episodes, and some extras. There are a total of 11 VTS, with 4 being dedicated to the episodes, and the rest being extras and menus, etc.

The 4 VTS's that correspond to the espiodes are about 1.3 gigs each. According to the DVD cover, this DVD comes with Japanese and English 5.1 tracks.

Two of the VTS tracks are normal. They show one PGC, 2 audio and 2 sub tracks.

Two of the VTS are INCREDIBLY odd. They are shown having 3 PGC's, with identical lengths and chapter points. The odd thing is : PGC1 is shown having 3 audio tracks(0x80-0x82), PGC2 as 2 audio tracks (0x80-0x81), and PGC3 as having 1 audio track (ox82). All 3 have subracks 0x20 and 0x21.

When I open up this VTS in PowerDVD, it shows a video being played at ~6Mbps, which is consistant with ONE ~25 minute video. Also, it shows 3 audio tracks, but the 3rd audio track is greyed out.

I am really curious what is going on here. As I said earlier, is there a bug somewhere, or is there some DVD feature being utilized that I do not understand? Also, any advice on how to ReAuthor this strange beast?

-Chu

[2COOL]

Originally posted by Chu
Two of the VTS are INCREDIBLY odd. They are shown having 3 PGC's, with identical lengths and chapter points. The odd thing is : PGC1 is shown having 3 audio tracks(0x80-0x82), PGC2 as 2 audio tracks (0x80-0x81), and PGC3 as having 1 audio track (ox82). All 3 have subracks 0x20 and 0x21.

I am really curious what is going on here. As I said earlier, is there a bug somewhere, or is there some DVD feature being utilized that I do not understand? Also, any advice on how to ReAuthor this strange beast? It's not a bug. A lot of anime DVDs are authored this way. I believe the people who authored this with 2 or more identical VTS_PGC_#s use each one to seperately to correspond to the audio you are using.

Though I don't have this series (Noir), I love doing anime episodic DVDs. It provides me with challenges on how to bypass unwanted stuff with new methods. Mobile Suit Gundam Char’s Counterattack R1 (http://forum.doom9.org/showthread.php?s=&threadid=58975) had the same thing you have with the identical Title PGCs.

I haven't dabbled with the big 3 method yet but there are other ways to back this DVD up. I'll try to find your DVD and see it's structure.

[mpucoder]

I'm not really sure what you mean by odd, and there certainly is no bug. I see nothing unusual at all about it. Many DVDs, not just anime, use multiple PGCs to present the movie in a different manner, this is the beauty of DVD structure, resources can be shared.
As for the audio being greyed out, it means that the audio is defined for the titleset but the particular title playing does not use the greyed out entry. Each title can use all or a subset of the audio and subpictures defined for the titleset.