vob editing newbie

[allpoints]

Here is my problem I have converted pal movie to ntsc every thing is great except the menu plays twice in the first vob then the movie starts normaly i would just use a one click copy program and remove the menu. But if i take the original dvdr img file it come up with ifo error and will not read disk. So what i did was use dvd decrypter got the movie files off into folder but the menu scene is incorporated in to the first vob with the moive. So I then used canopus pro coder 2 to get it into ntsc format, witch worked good but crashed when i tried to do pulldown, so changed to 29. whatever interlaced, output looks as good as original. But i want to remove the first 2 minutes were the menu scene plays twice, i have read quite a few forums i can demux all the vobs fine, but do not have a clue how to edit the vob and then put it back together. Any advise on an editing program that will edit the video and audeo at the same time, and the best way to put it all back together into working vobs to be burnt to dvd would be greatly appreciated.

[blutach]

If all you want to do is cut a few minutes off the start of the movie, use VobBlanker. Get it here (http://jsoto.posunplugged.com/vobblanker.htm).

With this program, you can "cut" a PGC on a GOP by GOP basis.


Regards

[jsoto]

Don't trust "open GOP warnings". It's more than a bug there... I'll fix them one of these days..

jsoto

[blutach]

@jsoto

Does that mean that if you get one of these warnings, that it's bad and to do your blanking over again (without warnings)?

Regards

[jsoto]

Here (http://forum.doom9.org/showthread.php?s=&postid=602327#post602327), in the firsts posts of this thread, the concepts of open, closed, broken, and self-contained GOP are explained by mpucoder.

What VobBlanker does is to check if the selected GOP is a closed one and warns if not. This is not correct. What it should do is:
- Check if the GOP is self-contained or closed.
- If not (so it is an open one), set the break GOP flag and (may be) warn the user.

And, last , there is another bug (pointed out by jeanl), in the code itself, so many times VB warns about an open GOP which is really a closed one.

So, forget the warnings. In the case you are really cutting in an open GOP, may be the first two B frames will not be decoded OK, but that's all.

jsoto

[blutach]

Very good jsoto. I thought there was no way VobBlanker could cut along a non-closed GOP, or at least, never do a cut that wasn't "safe".

I suppose that missing those first 2 B frames (if that happens) is not going to be a problem if you are cutting either:
(a) from the start of the PGC to a certain point or
(b) from a certain point to the end of the PGC
(that is, not within the PGC)?

Or will this be an issue if a type (b) cut happens? I guess there will be a discontinutity and a (very) short wait till the I frame, yes?

Thanks for clearing this up.

Regards

[jsoto]

No, the potential problem is not related with SCR or PTS discontinuities

The problem is the MPEG-2 decoder. It has lost the references (because they have been cutted) to properly decode the two first B frames. So what the decoder can output at the begining is:
- two bad (blocky) frames
- two black frames
I believe the most of them outputs two bad frames.
But, if VB porperly sets the break GOP flag (which is not currently doing), the problem should be solved.

jsoto