What did they do

[raylise]

Can anyone tell what people do in production of a DVD to inhibit time seeking while playing the DVD?

To explain further, here are some details of a problem I've just encountered.

I just bought a new documentary DVD set of 5 DVDs but find I can not seek or go to specific times of play in the movies. This is a nuisance since often I backup a few minutes to replay a part of the DVD I want to rehear.

Details of things tried:

(1)Players tried with results,
(i) Nero showtime, just ignores movement of the seek time slider bar for this DVD set
(ii) Gom, WindowsMPlayer, MPClassic all will CRASH when I move the seek time slider,
(iii) for some strange reason VLC works with strange behavior that seektime bar is limited to within a chapter (can't seek to time outside a chapter)

(2) with all players I can move the chapter seeker bar, or use commands to go to particular chapters without problems. Only the time goto doesn't work.(so not related to player software)


(3) Other computers tried: 3 others, same results, can't go to particular time.(so not related to hardware or windows version)

(4)Other DVD movies tried: hundreds, they ALL work fine. With them all I can seek to any time without problems, on any computer, with any player program (so not related to hardware,software problems).

(5)Other DVDs from the set tried: all 5 in the set. All exhibit the same problem: can't seek to any specific time. (So it is not just one bad DVD but something common to the whole set. The problem is in the method of production/authoring of the set of DVDs)

(6) Diagnostics tried so far:used 3 different Protection scanners, none report any protection used in producing these DVDs.

(7) Copying tried: used DVD shrink, ISO buster to copy, no problems copying. Everything works fine in the copy except, again, on the copies I can not seek to any particular time without crashing the player.

(8) Breaking of DVD structure tried: copied only the VOB file over to a directory (leaving behind the IFO and BUP files). Everything works OK. Can seek to any time, with all players.(Of course with windowsMP I had to change the file extension from vob to mpg) SO again the problem is related to the method of production of the DVD set)Of course I could just copy over the VOB files and view everything that way , except that I also want to use the MENUs on the DVDs etc.


(9) I quickly ran pgcedit but all I could see (after telling me there were 0 buttons over video) was a command to "jump to title 1" where it merely says set gprm(0) = (mov)0. followed by exit.

Anyone have any suggestions on how I can get around this problem? What did they do in production to make the DVD set this way?

[blutach]

They put the time search PUO on (either in the IFOs or VOBs or both). Remove them either when ripping or with PgcEdit (double click on the title PGC and enter 0 in the PUOs box and OK and save).

Regards

[raylise]

but there are no puos

Both Ifoedit and pgcedit say the DVD has no PUOs. With vobedit I randomly sampled some navigation packets and also no prohibited user ops anywhere.

[r0lZ]

Welcome to the forums, raylise!

There might be several causes to this problem.

• The PUOs. Seems they are OK for you. Don't forget to verify them also in the Title Play Map Table (Menu Title of PgcEdit), and clear them in the VOBs also (with the PUO plugin for PgcEdit.)
• Missing or bad time maps. Try to rebuild them with PgcEdit. (See in the PgcEdit menu "Title".)
• The title is not a one-sequential title. This is the most complex situation. A title can be sequential only if it is made of one and only one PGC. If, for some reason, the DVD authoring has split the title in several PGCs, you cannot fix the problem. But sometimes, there is only one PGC with video content, and some additional dummy PGCs. In this case, most players will accept to seek in the title if you rebuild the time map and turn off the "Not One Sequential Title" flag in the Title Play Map Table. But beware! Doing this is illegal, and may cause some players to crash, although I've never seen that.
• It is also possible that the "Not One Sequential Title" flag in the Title Play Map Table has been set without good reason. In this case, you can turn it off, and rebuild the time maps.

In short: verify the PUOs and the Not One Sequential Title flag, and rebuild the time map. Try it, but do a backup of the IFOs first, just in case...!

[raylise]

thanks

Thanks R0iz

I checked, & the flag
"Not One Sequential Title"
was indeed set.
I cleared it and now everything works well.

One question that puzzles me though,
you mentioned rebuilding the time maps,
but when I do that in PgcEdit I just get a dialog box asking
if I want to set the flag "Not One Sequential Title".


Whether I select yes or no it doesn't seem to do anything except adjust
the flag value. I expected it would have to do some computing
for a considerable length of time to reset all times in all vobs. Did it
actually do anything beyond setting the flag?

[blutach]

Sounds like it is a not one seq title. And on many players, these do not time seek.

Regards

[r0lZ]

Hum, even if the title is not sequential, PgcEdit should rebuild its time map.

Are you sure you selected "Rebuild All time maps in DVD"? You can also select the title in the left pane and rebuild the time map of that title only, but rebuilding them all is better. The procedure is relatively long, as PgcEdit has to scan all title VOB files. But note that it doesn't modify them, as the tables are stored in the IFOs. (Usually, if you repeat the operation, it takes much less time the second time, as most of the blocks needed by PgcEdit to compute the time maps are still in the buffer of the drive.)


Have you seen this dialog?:

Title X is marked as one_sequential_title in the Title Play Map table.
However, due to the Title characteristics, it is probably not safe to declare it so.
Setting the not-one_sequential_title flag has one drawback: normally, the user cannot
seek to a specific time in non-sequential Titles. However, some non-compliant players
let him use that function anyway.

Do you want to set the not-one_sequential_title flag for Title X?

If it's the case, you should not clear the flag, unless you are sure that you will watch the DVD only on a player that supports the cleared flag.

[gonwk]

Hi r0lZ,

The pointer that you just shared with raylise ... is that covered in YOUR GUIDE or any of the 3rd party guides on your HomePage!?!?

Thanks,

G!

[r0lZ]

I don't think so.

On this subject, you should still know this:

• If a title is declared as Random or Shuffle (and even if it is made of only one PGC) it must theoretically be declared as not-one_sequential too. Anyway, it doesn't make sense to seek to a specific time in a PGC when the cells are played in a non-predictive order.
• Since the Prev/Next/GoUpPGCN links in a Title PGC must point to a PGC pertaining to the same Title (or TTN), they should be 0 (disabled) in a sequential title. Some players consider the title as not-one_seq if one of those values are non-zero. For example, PowerDVD disables its seekbar when such a title is played. However, if the title is made of only one PGC and has one or several of the links pointing to itself, the PGC can safely be considered as one_sequential. The DVD-Specs are not clear on this point (and on many others btw!)
  The "Enable All Operations" function of PgcEdit forces the Prev and NextPGCN links of the PGC to point to itself, but this could have the effect of disabling the seek to time function of some players. Unfortunately, there is no good solution to this problem.

The two points above should not concern raylise's DVD, but now you know everything on the "not-one_sequential Title" subject.
No need for a guide!

(BTW, this subject has also been extensively discussed at Doom9.)

[raylise]

it is the time maps not the flag

I've been playing a lot with PGCEdit (repeatedly trying things, deleting, and then bringin in copies of backups etc)

and my first thought -
that of unchecking the "not one sequential file" flag turns out to be wrong

Pgcedit did in fact rebuild the time maps.

And that seems to be more important than setting the flag.

In fact in one experiment the DVD doesn't run if the flag is not set! (even though originally it didn't run if the flag was set). (Perhaps I forgot I did something else that time?) Because now in never runs properly without the flag set. So, to repeat, turns out rebuilding time maps was the solution.

[blutach]

Don't play around with the Not One Seq flag. PgcEdit knows what titles are sequential and will mark the title play map table accordingly.

Regards

[raylise]

still no real answer

so rebuilding the time maps fixes things but
that still doesn't answer the orginal question,

What did they do?

Some possible thoughts are
Did the original authors of the set of 5 DVDs purposefully alter the time maps to be incorrect?
Is it just that they used a terrible authoring program that didn't know how to do time maps properly?
Did the manufacturing "pressing" of the DVD set introduce errors?
Is it an error at all?

[blutach]

Without looking at the IFOs we are only guessing (and you can't post IFOs on the fourm).

Regards

[r0lZ]

Without your IFOs, as blu said, it is difficult to know exactly why they did that, but if the not-one_sequential titles exist, it's for good reasons, as you know now. But I've often seen DVDs with Titles in several PGCs without a good reason to do so. Sometimes, it is easier to program the jumps from title to title for the Play All function with not-one_sequential titles. Usually, the authors use that method in compilations of short films, and I suppose they think it's not really important to be able to seek to a specific time in the title. (BTW, this function is usually difficult to access on standalone players and therefore rarely used, but it's really easy and intuitive with the seekbar of the software players. Most companies ignore the fact that a DVD can be played on a computer! Have you noticed how difficult it is to highlight the menu buttons of some DVDs with the mouse, just because the active area is too small? No problem with the remote!)