demux DVD Video to MPG!

[GangstaRap]

i want to demux VIDEO_TS file to MPG,
but every tool i tryed only has VOB to M2V+AC3 function!
couldnt find one decent VOB to MPG tool.
i tryed VOB2MPG but it causes an open GOP in my video!

do you have any ideas on how to close it?
dont forget i'm newbie, so if its to complex - i prefer other VOB to MPG tool...
any suggestions?

Thanks in advance!

[mats.hogberg]

I'm pretty sure if VOB2MPG gives you an mpg with an open GOP, the VOB also has a video stream with an open GOP.
OTOH, if you can get a M2V+AC3 withouit this problem, it's a simple matter to myx it back as mpg. Use mplex or TMPGEnc or...

/Mats

[Abond]

Closing or opening GOPS is an encoder task. VOB2MPG isn't an encoder. To close a GOP you need to reencode it.
I don't know what is the purose to obtain a mpeg, but you can multiplex m2v and ac3 with ImagoMPEGMuxer to a mpg.
You have already 171 posts - I tend to forget you are newbie...

[GangstaRap]

mats.hogberg, Abond,
thanks for your help guys...
i'll try it!

I don't know what is the purose to obtain a mpeg

much easier to cut/merge MPG files then M2V+AC3 files...

You have already 171 posts - I tend to forget you are newbie...

and yet, they're all crying-for-help posts...

Thanks guys!
you're the best!!!

[Abond]

That is why I am using Cuttermaran. It need elementary streams and, well, is easy. As a bonus it can cut only audio finding the cut points using the video. It has preview at cuted/merged sites.

[GangstaRap]

Abond,
Thanks for the advice man,
i'll try Cuttermaran.

one last question:
what if i'll cut video, any video, can it cause an open GOP?

thanks in advance!

[Abond]

Hehe, your question is too general. Well if it is avi - surely no ('cause there are no GOPs in avi at least in sense of mpeg2).
Anyway, it depends of the cutter. If you use reliable editing application it should not cause an open GOP. In opposite it should close the GOP at cutting site. But if you are using DOS to cut... (yes it is possible as it is a bitstream!) well you can answer yourself.
I don't know why this closed/opened GOPs are such a mystery. A good encoder would close the GOP at scene change when (of course) scenechange detection is activated. Why? Simply because these are potential chapters. But it is not the only reason. Now you may know that B and P frames of a closed GOP doesn't relay to the I and P frames of previous GOP. Imagine a scene that is in the night, folowed by the scene that is in a day. Well, both scenes are different like a night and day . Sure the day scene first GOP can not relay on the night scene GOPs (well it can, but it would hurt the video quality or the file size). So this first day scene GOP must be closed. OTOH when you have a chapter start the authoring application create a internal file entry point. That is like you start the stream from the very beginning - then the GOP must be closed - there isn't anything to relay before the beginning of the file.
Now the open GOP messages are simply warning - they are not errors. Hardware players can cope surely with such an issue. Sometimes you can observe some macroblocking at the I frames of the open GOPs at scenechange, but only if the bitrate is very low.

[borax]

No, cut points usually cause closed GOPs.
BTW: What's wrong with open GOPs? 99.9% of my videos (captured DVBs) have open GOPs...

[GangstaRap]

Abond,
thanks for the great explanation man!
it really helped!

i cuted my [m2v+ac3] files with Cuttermaran, it worked great!
thanks!
now how can i merge few [m2v+ac3] with Cuttermaran?
i couldnt find this function...
i'll be very grateful if you'll show me how to merge them...

borax,
i'm authoring it with DVD Lab Pro,

Now the open GOP messages are simply warning - they are not errors.

yes, indeed...
but the last time i tryed to author an open GOP video - it ended bad!
the compilation process stoped without any reason!
the only suspect i had is the open GOP...

so i prefer to avoid it...

Thanks for your great help guys!

[Abond]

Load the first video to be merged. CutIn at the very first frame, CutOut at the last frame. Add to Cut List. Now open the second video to be merged. CutIn at the very first frame, CutOut at the last frame. Add to Cut List. Now open the third video and repeat the operation. Once you have all of them in the cut list in appropriate order, click Cut Audio-Video

[GangstaRap]

Abond,
naaaice!
thanks man!!!
you helped me a lot!