Captured MPEG2 - Do I have to do Inverse Telecine?

[dominic01]

I captured certain TV serials into MPEG2 format. These MPEG2 are in DVD format.

Just wondering wheather Inverse Telecine (IVTC) is requred on these or not.

If it is required will that improve any quality or reduce file size.

How do I do it wihout re encoding it?

Thanks group

Dominic

[FOO]

It seems like a good idea. IVTC only has to store 4 out of
every 5 frames which increases the effective bitrate per frame.
It also essentially makes the video progressive.
The problem is it causes lots of problems in editing.
MPEG2 is bad enough already but when it's Pulled down Film
it gets worse.

[SLK001]

MPEG2 is bad enough already but when it's Pulled down Film it gets worse.

Baloney. In fact, a 2:3 pulldown is required on NTSC films.

But FOO is correct in that you can allocate approximately 20% more bitrate if you perform an IVTC.

In your case, your capture is already at 29.97, so I wouldn't do anything except author and burn. You will not pick up any more quality (but you might pick up space). Plus, it would require to re-encode.

[DivXExpert]

He says it causes problems when editing. And it does. But its stupid to edit things as MPEG-2 anyway. You keep is lossless to edit. Then you convert your final product to MPEG-2.

[non-linear]

I don't see why you need it. I don't use it for anything I capture and the stuff turns out great.

If you're capturing from tape or broadcast that is in the regular NTSC SMPTE drop frame of 29.97 fps and capturing your video at 29.97 fps, then what's the point of running the inverse telecine?

[DivXExpert]

The point is saving space, and making it better quality. IVCT is the best method of de-interlacing, no one is going to argue that. The only problem is not all material can be IVCTed. You can only Inverse Telecine, if the video has been telecined (23.976fps source). You stuff may look good without IVCTing, but it will look better when you do.

[FOO]

I guess I have to clarify this as I don't eat baloney.

24 fps video has to be pulled down to play at 30.

There are 2 ways to do this
1. Actually generate and store the 5th frame. This is what you get when
you capture a movie from the tuner.
2. Set the Pulldown flags in 24 fps MPEG2 video. This is what you get
when you perform a IVTC. The player then generates the 5th frame
during playback.

With every program I've tried that claims to edit MPEG2, if the video has
the pulldown flags set, the audio gets out of sync or worse.
This includes TMPGenc and Womble MPEG2VCR. Rumor says
M2-Edit works but I don't have it. Another rumor says Ulead VS7 works
but i don't have that either.

I disagree that I'm stupid to edit MPEG2. I might claim that
you are stupid to waste so much time encoding when all you want
is a commercial free MPEG2 ready to be authored.

If I don't do IVTC, MPEG2VCR edits frame accurate perfect.