Exact points importing chapters into a NTSC film.

[Talayero]

Hello,

Well, my problem is not so important. I've backuped a few of NTSC films and I didn't get the very exact points for chapters.
I used chapter-X-tractor, with semi-colon option and imported into dvdmaestro.

The points are almost the same as in original, but there's always one second of time or a few frames of difference. I can correct that manually but I'm wondering if there's another way to get preciser marks.

Thanks in advance.

[Matthew]

Authoring software can only place chapters on i-frames, which typically occue every 12-15 frames (it depends on your GOP settings). When you re-encode your video the i-frame points are unlikely to match up exactly with those in the original, so you get these differences of a few frames.

The solution is to specify a list of i-frames in your encoder - provider it is supported. With CCE you can provide a chapter list and it will place an i-frame at each of those points. But other encoders (e.g. ProCoder) do not support this feature.

As an aside, I've found that if a chapter point and a subtitle intersect, DVDMaestro will cut the subtitle short. So that's something to look out for also, although it shouldn't usually be an issue in commercial dvds.

[Talayero]

Thanks, that's very interesting.

I'm going to use the search function in order to learn how to place that chapter list into cce (I have 2.67 and 2.7 versions).

Anyway, the thing is that I have only noticed that problem in NTSC films. I don't know why. May be in PAL films there's no such an i-frame issue.

[Matthew]

The problem is independent of format, it occurs in PAL too (I live in PAL land).

NTSC does have an additional issue relating to chapter points (and subs), and that is drop-frame. But if that is the issue, towards the end of movie the chapters will be way out, not just by a few frames.

You can add the chapters to the end of the ECL like so

....
[file]
name=H:\bah\horney_midgets.avs
stream_no=0
encode_first=0
encode_last=143185
chapter=0:
chapter=9687:
chapter=21250:
chapter=30449:
chapter=35500:
chapter=42749:
chapter=53382:
chapter=61365:
chapter=74300:
chapter=79494:
chapter=85961:
chapter=93695:
chapter=100193:
chapter=110712:
chapter=118406:
chapter=126470:
chapter=137608:

[Talayero]

Thanks again.

I added the chapters like you said to the ECL and it worked: I got the chapters marks exact in the same place as they were in the non compressed m2v.

But may be I did something wrong because I can notice the film freezes a fraction of second every time it changes from a chapter to the next one. It' s like the layer break effect.

That's what I did:

First I added the chapters to the ECL (I did it manually, that's to say, I extracted them with ChapterXtractor using the micro dvd player format and copied manually the figures. I don't know if there's a way to get directly the format: chapter=0: chapter=9687: etc)

Well and finally I placed the compressed mpv into DVDMaestro and imported the chapters extracted again with ChapterXtractor using DVDMaestro format with semicolons at the end.

The result is the points are exact the sames but they freeze at every change.

[Talayero]

I found the solution. I put the drop frame flag to the stream and these freezings disappeared.

Now for the next time the only thing I would like to know is if there is a way to extract the chapters directly in the format that the ecl file needs.

[manono]

Hi-

Yes, you can get them in CCE format through DVD Decrypter. Go Tools->Settings->IFO Mode->check "Chapter Information-CCE". Then begin decrypting in IFO Mode the PGC you want (the default Main Movie, most likely). If you don't really want to decrypt it, then Cancel it almost immediately, and you'll have what you want.

There may be other ways, but that's the one I'm familiar with.

[Talayero]

Thanks. That's very useful.

I was about to add a post to this thread, just to say that I was wrong: I didn't find the solution for that freezing problem. The 1 second freezing at each chapter occurs after merging the dvd with another one using dvdremake pro.
The other day I tried adding the drop frame flag, because I read something about it, and then I burnt a dvd +rw and was glad to see no freezing, but that was before the merging.

I'll write a post in the ifo/vob editors section about this dvdremake issue.