Help with MPEG-2 structure

[Wolf359]

I'm looking for some help about the structure of a MPEG-2 video to try to clarify the sync problems found in edited MPEG-2 made from Videoblaster VCR exported files.

Analyzing one of this exported mpeg-2 file I found distincts segments with differents GOP sizes and differents framerates. Some have 29.97 (NTSC) and others 23.96 (FILM). Also some are interlaced (2 fields) and some progressive.

Is this possible? If so, how do the mpeg2 editors, like MPEG2VCR manage them? Could this be the reason of the strange sync problems?

If you have any info about sync problems in MPEG-2 edition please give me a small reply

Thanks.

[kwag]

Have you tried processing your captured file with an AviSynth script?.
It might just be the ticket, if your source is mixed FILM/NTSC.

kwag

[Wolf359]

Hi, kwag, and thanks for your reply.

Actually I'm looking for a quick (and maybe dirty ) edition process for convert a large VHS colletcion to SVCD (ou DVD) using a mpeg-2 analog capture card (I'm using a Creative Digital VCR). Caping TV shows are also another use.

I won't like to make much processing with these files. I'm capturing video with a preset of 2.2kbps rate, quite good for 45 min SVCDs. But they need some edition, like cutting, fade in/out. But no mpeg-2 editor can handle files without loosing sync.

Do you think mixed FILM/NTSC could be the reason of all my sync problems? And if so, is there an mpeg-2 editor capable of do this task with this mixed thing?

Thanks.

[kwag]

Hi, kwag, and thanks for your reply.

Actually I'm looking for a quick (and maybe dirty ) edition process for convert a large VHS colletcion to SVCD (ou DVD) using a mpeg-2 analog capture card (I'm using a Creative Digital VCR). Caping TV shows are also another use.

I won't like to make much processing with these files. I'm capturing video with a preset of 2.2kbps rate, quite good for 45 min SVCDs. But they need some edition, like cutting, fade in/out. But no mpeg-2 editor can handle files without loosing sync.

Do you think mixed FILM/NTSC could be the reason of all my sync problems? And if so, is there an mpeg-2 editor capable of do this task with this mixed thing?

Thanks.

I guess that you just want to cut off parts of a video, and you are not going to re-encode, if I understand correctly?

Try something quick. Open that mpeg-2 file that you captured with DVD2AVI. And press F5. Let it run for a while, and see if it shows in the statistics window NTSC or FILM or some% FILM.
That way you can see if the capture is mixed. Which shouldn't be! It should be 29.97 interlaced all the way!.

kwag

[Wolf359]

You are right, I want to cut off commercials and burn SVCDs to make a private collection of my favorite TV shows, and also convert my private VHS collection to SVCS.

About DVD2AVI: Nope. It says something about 94% of NTSC. And some frames are interlaced and some progressive. A really mess, huh?

I think Creative develop team decided to make this thing this way for optimizing purposes.