Can't Skip Previews on Back-up

[trubeliever]

Wow, I didn’t expect to see so many replies, but I’m still left wondering what exactly does “Remove the IFO Structure Protection,” of DVD Decrypter mean, or do? Also, is there a reason why RipIt4Me disables it?

[cynthia]

what exactly does “Remove the IFO Structure Protection,” of DVD Decrypter mean, or do?

http://forum.digital-digest.com/show...1&postcount=14

[blutach]

@Calimari

When you see that PgcEdit has added 2 sets of post commands (when you have blanked/killed playback only once), it:

(a) does no damage whatsoever, as the first set will be executed only (unless GOTOs skip over them)

(b) usually indicates that not only are post commands present, but also there may be NextPGCN set (you see this quite a bit for multi PGC titles).

The NOPs are handy "separators".

Not sure if this is turning more into an authoring and editing discussion.

Regards

[blutach]

Also, is there a reason why RipIt4Me disables it?

Because, it substitutes it own routines (which take care of the more advanced versions of ARccOS that came along after DVD Decrypter's development ceased).

Regards

[Vaios]

I experimented a little. It seems that RipIt4Me doesn`t override the setting you have for the removing of IFO PUOs. But the last year with the use of PSL Plugin that needed the default preferences, I had the removing of puos unticked (the default of dvddecrypter). Now I opened dvddecrypter alone and ticked the option and RipIt4Me left it as it was . So I would guess that the option in dvddecrypter`s preferences of removing IFO PUOs is not important for RipIt4Me. I don`t know the reason, perhaps it removes them at some other stage when it`s writing the IFOs ???

[blutach]

@Vaios

No, it doesn't. It's a user preference.

Unlike r0lZ(!), I remove IFO PUOps and leave VOB PUops in.

I know I can remove the Puops easily in PgcEdit, but in any case, all I ever do is set my menus as described above (Prohibit Previous and Next Program search in menu PGCs).

As for VOB Puops, if there are no angles on your DVD, it is safe to remove them (you can find this out easily in IFO mode of DVD Decrypter). But if angles are present, you wanna retain them - many players actually display the angle icon on the screen during the entire time an ILVU block is being played if VOB Puops are not present.

Regards

[Vaios]

Could you please tell us which puos, ifo or vob , are responsible for functions that are not allowed in specific cases ?
For example
When the menu button during previews doesn`t work ?
When next or forward button doesn`t work during a warning screen?
Some times I noticed next doesn`t work but forward does , during previews .
When we cannot change subtitle or audio during the movie with the buttons on the remote control, but we have to go to the menu ?

[r0lZ]

PUOs:

• Time play or search
• PTT play or search
• Title play
• Stop
• GoUp (Not used in PGCs)
• Time or PTT search
• TopPG or PrevPG search -> When prev button doesn`t work during a warning screen?
• NextPG search -> When next button doesn`t work during a warning screen?
• Forward scan
• Backward scan
• Menu call - Title
• Menu call - Root -> When the menu button during previews doesn`t work
• Menu call - Subpicture
• Menu call - Audio
• Menu call - Angle
• Menu call - PTT
• Resume
• Button select or activate
• Still off
• Pause on
• Audio stream change -> When we cannot change audio during the movie
• Subpicture stream change -> When we cannot change subtitle during the movie
• Angle change
• Karaoke audio mix change
• Video presentation mode change

Note that there are also other causes for some "prohibitions".

1. With most players, it is not possible to use the prev button when the first program (or chapter) is playing. It's often the case when the player has implemented the prev button to go back to the beginning of the previous program. A good player should come back to the beginning of the current program, unless the playback is just at the beginning of the program, in which case, the player should jump to the previous program.
2. With most players, it is not possible to use the next button when the last program (or chapter) is playing. This is why there is often a short black cell at the end of the movie, to let the user skip to this last dummy chapter, and continue normally with the post-commands.
3. The Fast forward and Rewind buttons might not work when the search pointers are not correct in the VOB files.
4. The jump to a specific time might also be disabled if the Time Map is missing or empty, or when the title is not a "sequential title".
5. There is also the so called "restricted play" flag on some cells. It is rarely used (except on the ARccOS protected cells), but has virtually the effect of disabling almost all buttons of the remote when the cell is played.
6. Don't forget the Time Play or Search and PTT Play or Search PUOs of the global Title Play Map table.

Almost everything can be "fixed".

Points 1 and 2 can be fixed with a trick: setting the PrevPGCN and NextPGCN links to point to the same PGC is usually sufficient. However, this technique has a disadvantage: when the Next, Prev or GoUpPGCN links are non-zero, some players assume that it's not a sequential title, and therefore prohibit the jump to a specific time. According to mpucoder, it's an error, as the Next, Prev and GoUpPGCN links can be non-zero if they point to a PGC belonging to the same title. Since it points to itself, the condition is met. But it's not sufficient for some players (notably PowerDVD) and therefore this technique is not always recommended.

To enable the Next button without this NextPGCN problem, you can also create a new tiny cell at the end of the PGC, and assign it a new program and chapter number. This technique is perfectly legal.
Unfortunately, this technique doesn't work always for the Prev button, as you have to insert a new chapter at the beginning of the title. The original chapters will therefore be shifted by one, and that can cause some navigation problems, especially for the main movie. But it should be safe do it on simple trailers, and generally on any PGC with only one chapter.

Point 3 can be fixed with VobBlanker, with the option Fix always VOB SYNCI/SRI pointers in Titles/Menus.

Point 4 can also be fixed with VobBlanker, but you can also rebuild the Time Map with PgcEdit.

Point 5 can be fixed via the cell table in the PGC Editor of PgcEdit.

Note that a Menu PGC cannot have a Time Map. It is therefore impossible to seek to a specific time when a menu is playing. Some trailers or logos are authored in the menu domain, and therefore, although they look like a title, without buttons, you cannot use the time seek functions.

Note also that when a Title is really non-sequential (either because it is spread over several PGCs or because the Random or Shuffle flag is set in the PGC), the Time Map is theoretically ignored. In this case, point 4 cannot be fixed. However, some players are still able to use the Time Map on a non-sequential title. This is why PgcEdit let you rebuild the time map of any title, including non-sequential ones.

If that sounds complicated, don't worry too much. There is an handy function in PgcEdit to "enable all operations" on a specific PGC. This function clears all IFO PUOs for that PGC, sets the Prev and NextPGCN links to point to itself, and offer to clear the restricted flags. If you have a good player, it's usually sufficient to enable the Prev and Next buttons. Note that this function doesn't modify the VOB PUOs.

Since rebuilding the Time Maps is a long process, it's not automatic. But you can use the time map plugin to verify if the time map of all Titles of the DVD are defined and correct, and rebuild only the missing/wrong ones.

[Calimari]

@ rOLZ

About wrong or missing time maps, is this causing MPC to hang whenever I move the postion slider to a random position during main movie playback?

I had this problem with Da Vinci Code R2, it seems to work perfect now after rebuilding time map in PgcEdit. Or is this a coincidence?

[r0lZ]

I didn't know this MPC bug, but yes, it is probable that it's a missing or invalid time map that caused the problem.
Maybe the original DVD has the "Time Play or Search" PUO set so that the player does not need the time map anyway...

[blutach]

Points 1 and 2 can be fixed with a trick: setting the PrevPGCN and NextPGCN links to point to the same PGC is usually sufficient. However, this technique has a disadvantage: when the Next, Prev or GoUpPGCN links are non-zero, some players assume that it's not a sequential title, and therefore prohibit the jump to a specific time. According to mpucoder, it's an error, as the Next, Prev and GoUpPGCN links can be non-zero if they point to a PGC belonging to the same title. Since it points to itself, the condition is met. But it's not sufficient for some players (notably PowerDVD) and therefore this technique is not always recommended.

I have no issues with PowerDVD v6 honouring this technique. Generally, if it doesn't, VOB Puops are present.

Point 3 can be fixed with VobBlanker, with the option Fix always VOB SYNCI/SRI pointers in Titles/Menus.

In my view, it's a good idea to have this on permanently.

Moving thread to Authoring & Editing forum.

Great discussion topic!

Regards

[r0lZ]

I have no issues with PowerDVD v6 honouring this technique. Generally, if it doesn't, VOB Puops are present.

Maybe it's WinDVD then; I don't remember.
Anyway, I have heard that this problem is also present on some standalone players. But I have no problem with my standalone players, and with MPC, VLC, IfoEdit's Play DVD, and Nero ShowTime.