Choppy playback only on ST:TNG rips.

[PapaBobDole]

Hi,

This is probably a n00b problem so go easy on me. :D I am encoding with DiVX 5.1 (previously with 5.05, same problem) and using Gknot .28.5, ripping using Robot4rip. B frames and GMC are enabled, no Quarter Pixel or psychovisuals. 2 pass, slowest. I have the feeling this is some sort of interlacing issue after reading the FAQ on it, because it is choppy only during the high motion scenes (for instance the intro to ST:TNG where it pans by the planets and whatnot). I assume Robot4rip does not automatically force FILM since the frame rate comes up in Gknot as 29.97 and when DVD2AVI is running it never sustains over 95% FILM. I assumed IVTC would work at first thinking it was telecined, however that seems not to be the case as it appears interlaced (at least some of it). I could not get any of the options on that deinterlacing menu where you selecty IVTC to work at resolving the choppiness however. Is there anything I'm overlooking? I know some of you Star Trek geeks have ripped this series successfully, any advice for a n00b to ripping TV series material? TIA,

Nate

[jggimi]

Congratulations, you are working with hybrid content. Some of it is shot on film, some on video. IVTC can't be used, as you would remove 20% of the content in the video portion, and you can't just leave it with no filtering, as you still have interlacing artifacts.

Check out this tutorial on IVTC (http://www.doom9.org/ivtc-tut.htm) which will give you a great deal of background, but which will also give you a couple of choices for what to do with the dreaded hybrids.

[Hectic]

thanks for posting that link jggimi it answered the question i had. i came here to post a question about a concert dvd i'm trying to enocode. i tried to ivtc it but ended up being choppy. so i guess my only option is to de-interlace it...damn, it's gonna look crappy if i leave it at 30 fps even on 2 cds..it's pretty long. thanks again. don't mean to intrude on the thread here..

[cjaar]

@jggimi

I created a .d2v file, dvd2avi said that its NTSC 29fps and was constant all over. I saved as it is(no force film). I examined the .d2v file in GK, to see any interlaceing effect, i.e all frame intralced or 2 frame interlace out of 5 frames(as per the ivtc guide)
but i didnt see any such thing all over.

Now can i change the fps from 29 to 24 ???... to save some bits for
video and audio or i hv to live with it ??? i did read the guide, wher it said that if fully interlaced, not to ivtc and ivtc for 2 frames interlaced out of 5 frames.

thanks
cjaar

[PapaBobDole]

Originally posted by jggimi
Congratulations, you are working with hybrid content. Some of it is shot on film, some on video. IVTC can't be used, as you would remove 20% of the content in the video portion, and you can't just leave it with no filtering, as you still have interlacing artifacts.

Check out this tutorial on IVTC (http://www.doom9.org/ivtc-tut.htm) which will give you a great deal of background, but which will also give you a couple of choices for what to do with the dreaded hybrids.

Thanks jggimi, that was extremely helpful. I missed the hybrid section the first time around.

[jggimi]

@cjaar:

I created a .d2v file, dvd2avi said that its NTSC 29fps and was constant all over. I saved as it is(no force film).

That is what I would do. Force FILM is a quick IVTC using the FILM flags in the MPEG-2 stream. If the flags aren't there, you can't use Force FILM.

I examined the .d2v file in GK, to see any interlaceing effect, i.e all frame intralced or 2 frame interlace out of 5 frames(as per the ivtc guide) but i didnt see any such thing all over.

If you did not see any interlace artifacts at all, then I can think of only two possibilities: You are looking at progressive video at 29.97 fps, not at film content, and you should not IVTC.

Your frame-by-frame examination was at so small a resized resolution that the interlacing artifacts had been removed, and you need to look at the content unresized.Now can i change the fps from 29 to 24 ???... to save some bits for
video and audio or i hv to live with it ??? i did read the guide, wher it said that if fully interlaced, not to ivtc and ivtc for 2 frames interlaced out of 5 frames.

If the content appears to have no interlace artifacts whatsoever, then it need not be deinterlaced. And if it does not show a pattern of interlace artifacts from Telecining, it should not be IVTCed. My guess is that you are looking at resized video, which is hiding your interlace artifacts. That is because progressive 29.97 video on DVD is rare, compared with the vast number of film transfers.

[cjaar]

@jggimi

Thanks for the info, i did try checking the frames in GK without resizing, but i coudnt see any interlacing articrafts!!!! strange what all dvds(29fps) i encoded were either de-interlaced or ivtcd.

i hv to live with it :)

thanks
cjaar