Wanted: IVTC plus Deinterlace Suggestions

[Kedirekin]

I'm looking for suggestions on how to encode a movie with a strange form of telecine.

The movie is Roujin Z. Yes, it is anime. It appears to be based on a 24 fps source, but instead of a nice clean 3/2 type of telecine, it has a kind-of progressive-blend telecine that produces varying intensities of interlacing over 3 or 4 frames out of every 5.

I just tried encoding it at 29.97 fps, but with the limited bitrate of SVCD, it turned out very poorly (lots of mpeg artifacts).

I'm going to try a standard IVTC on it (probably this afternoon), then encode it as interlaced (with the original field order) in the hopes that it'll look okay, but I don't have high hopes. When I IVTC, I know I'm going to end up with interlacing artifacts, and because of the way IVTC works, I expect that field order between any two 'artifact' frames will be completely unpredictable.

I suspect I'm going to have to deinterlace after IVTC to get watchable results (and I can only hope playback will be smooth). And that is where I'm asking for advice. I've never done deinterlace before, and I'd rather not have to try the half-dozen (or more) different approaches myself.

Ideally what I'd like is something that maintains the 'sharpness' of frames that have no artifacts, and 'merges' (for lack of a better term) areas with artifacts to create pseudo-progressive frames. Even more ideally, it'd be great if the merging only softened areas within a frame where interlace artifacts are present (or maybe this happens naturally).

I'm willing to live with some softening to get better use of the limited SVCD bitrate. I have plenty of hard drive space for this, so even processing though vDub filters (telecide?) to an intermidiate huffy avi is acceptable.


Any suggestions? Or do you think this just plain won't work?

TIA

[Friday]

I know where you're coming from...been there...tried all that.

I did come up with a solution but the circumstances have to be right.

First of all...you need a standalone that supports 720 480 resolution and >2600 bitrate. My Apex does.

What I did was just rip the m2v and ac3 files from the vobs leaving the m2v file intact. Convert the ac3 to mp2 of course. Mux and cut in BBmpeg and burn. Now pray it works. In my case it has flawlessly worked with a comparable source to anime(adult materail). The biggest concern will be whether the bitrate will exceed what your standalone can handle. Typically, with the bitrates used for adult film I get 20-25 minutes of video on one cd.

[Kedirekin]

Thanks for the suggestion. Unfortunately my Apex doesn't support very high bitrates - I can push video bitrate to maybe 2650 or 2700, but above that it becomes unreliable. I almost always stay within SVCD spec, because the extra 200 kbps or so just doesn't make enough of a difference to justify the violation - and I never know what my future players might support. Besides, I needed subtitles, so the IAuthor muxer imposes its restrictions on bitrate.

FYI: In the time between my original post and now, I did try out some deinterlacing approaches. My complete playing and reasoning is too lengthy to go into, but I'll give a thumbnail.

I decided the best aproach was to use vDub with the Smart Deinterlace filter. I believe the regular vDub deinterlace filter would have produced nearly the same results, but I decided to use Smart Deinterlacer because it's fancier (it has more settings). I set the threshold to a very low 5 to catch *all* the interlacing. Remember that the source is ultimately progresive - I just wanted to eliminate any field-order differences in the faint ghost-interlacing that remained after TMpg IVTC. Using a low threshold caught all the interlacing without impacting the progressive portions of the frames too greatly.

I also decided to use blend instead of interpolate in the filter. Because of the rather strange telecine in the original, it naturally exibits ghosting (I mean when watching the DVD itself on a TV), so I felt blend actually produced a better result. Using blend did result in a slight loss of sharpness, but it made the ghosting much more progressive-like.

Lastly, to offset the loss of sharpness a little, and to minimize the mpg artifacts present in high motion scenes on the DVD (it was far from a good master), I added the Smart Smoother filter (again, fairly low settings - 5 and 25, as I recall).

The final encode was far from perfect, but it did have fairly smooth playback (nearly as good as the DVD) and was greatly improved over the 29.97 fps encodes I did earlier. I think the ghosting may have actually helped the encoder - kind of like a massive temporal smoother. With the deinterlace approach, there were only a couple of scenes with significant amounts of artifacts (like Huroko running through the suspended trash near the end of the movie). In the 29.97 fps encode, that same scene was an undifferentiated mass of noise; you could hardly even recognize there was a human figure - let alone that it was Huroko.

Two final comments. The ghosting on the SVCD may have been slightly more pronounced than on the DVD, but it's a close call. I think it'd take and A/B test to positively comfirm it. Pretty good all told.

Also, my CCE speed frame serving from vDub with the filters was 0.110. Not for the faint of heart. The first part was only slightly more than 38 minutes, so I did it CBR, but the second part was long enough I wanted to do multipass VBR. Consequently, I saved it to intermediate avi first. The second part encoded while I slept, so I don't know what speed I got, but it finished a 5-pass encode between 11:30 PM and 7:30 AM the next day. Definately the way to go if you have the hard drive space.

Quite a thumbnail, huh? Hope you enjoyed the read :) . That's about it for this thread.

[Kedirekin]

BTW: Where do you get your adult DVDs? I'm as much of a pervert as the next guy. :D