Weird problem when using deinterlace filter from VirtualdubMod...

[artyjeffrey]

I have a video file that's about 34 minutes long. It's currently about 1.5 gigs in size. It needs deinterlacing badly. But when I utilize Virtualdubmod's filter, it gives me a projected final file size of over 50 gigs! What is causing this, and what can I do?

[redwudz]

Probably because you didn't set an output codec to save the filtered video to. VD defaults to a huge RGB file if you don't select an output format.

[artyjeffrey]

Ah, okay. So if I plan on putting this file eventually to dvd, what codec would be best for me? There's so many, and it could take forever to find out via trial and error.

[Gavino]

If your final target is a DVD, there's no need to deinterlace at all.

[manono]

Nor is there any reason to use VDubMod for anything.

[redwudz]

VD Mod only outputs AVI type formats. An authored DVD is usually MPEG-2.

Unless you are making a Divx/Xvid DVD data disc, then deinterlacing and the Xvid codec would be one choice using VD Mod.

Just to add, interlaced video looks crappy on a computer monitor unless the correct player or player settings are used. A player that deinterlaces should display the video correctly. VLC is one choice. Interlaced video is common for MPEG-2 DVDs that are displayed on a TV.

[EddyH]

To answer the question more straight:

If you want to keep it losslessly in-between, whilst working on it, save to HuffYUV (WITHOUT interlacing at this point, if DVD is one of / the only goal/s) or... there's a newer, better one whose name I can't remember. Lava-something?

Anyway these codecs use lossless compression... so your video may still end up as a good 20+ gigs, but at least it won't be 50, and you lose no quality in between.

If you really need to crush it, use DivX with maxed quality settings (something like 1-pass quality based at full resolution, quantiser=2.0 (or lower if it allows you to), make sure to set "interlaced" and put the pixel aspect correct...), which will still turn out a chunky file compared to what you'll eventually get (say, 1-2Gb), and may have some unavoidable artefacts even so, but it'll be a reasonable halfway house.

Then once you've edited it (if you're doing anything more than a very simple end-chop and filter, you'll need more than VDub, ditto for MPG2 encoding, but you can still frameserve to and/or from it), save to more conservative DivX settings if you want an AVI (remembering this time TO run the deinterlacer, but NOT the one in the encoder itself), or serve it to HCEnc / similar MPG2 encoder to get the DVD-friendly bit.
...and don't forget the audio!

[artyjeffrey]

Thanks for all of the input! Basically, this is my dilemma:

I had completed the mpeg-2, had it ready for authoring the my dvd, when I noticed a lot of "marching ants"-effect going on. The video was of a recent air show, and every time that I'd have footage of a plane/biplane ANY of the struts or slightly diagonal lines would have this choppy "marching ants" thing going on. I was hoping to find an easy way to take my mpeg-2 and repair this problem, so that I could proceed with my authoring.

[manono]

Give us small samples showing the problem - one of the source, if it doesn't show the problem, and one of your MPEG-2 encode that does show the problem. 10 seconds of each will be plenty. You can make M2V samples by opening a VOB in DGIndex, using the [ and ] buttons to mark off a small piece, and File->Save Project and Demux Video. Upload the resulting M2V to a 3rd party filesharing site (Sendspace, MediaFire) and give us the links.

Also, if the source doesn't show the problem, you might explain in detail exactly how you converted it to DVD video. You didn't happen to have to resize the source, did you?

[artyjeffrey]

Well, here's still capture that shows what's annoying me.

The original source was analog (a tape), and I used the capture card on my pc. No resizing was done along the way, I kept it at 720 x 480. Originally, I'd used my standalone dvd recorder and then had ripped the recording to my hd, but in both processess, the zig-zag lines still found their way in. I edited the file with Pinnacle Studio, and outputted it as a dvd-compatible mpeg-2, again at the same resolution.

Is this annoying effect simply par for the course when dealing with transferring video from a tape source to a dvd (digital) source? Thanks for responses.

[manono]

I said video and not pic. A picture is next to useless. Perhaps because it's widescreen 4:3, there's just not enough resolution to resolve fine diagonal lines. However, it looks to me like standard interlacing and it'll look fine when watched on TV. Have you burned it to disc yet and tried? Since you say it's also in the source, in the off chance it's a capture problem someone else will have to comment as I've never capped anything in my life. How does the source tape look? Is it a VHS tape?

[artyjeffrey]

I'll burn it and check it out on my tv. As you said, it could just be the player on my pc. The source was an 8mm camcorder tape.

[EddyH]

From looking at that picture it could be...

a/ just a very sharp recording/capture so you're getting noticable aliasing of the lines where they break at line/column boundaries. Not much that can be done there, except maybe running a soften filter on the whole thing.
b/ similar to above but caused by poor (nearest-neighbour) resizing at some point. not sure why that would happen in a camcorder -> DVD workflow though. This won't be fixable without starting over.
c/ your preview player not doing decent de-interlacing, therefore screwing up the vertical resolution or frame order. I'd suggest burning a test copy and playing it on an actual TV to see if it looks as bad once finished, because the actual video data might be A-OK in reality.
(a and c as manono mentioned, really

or, what wouldn't be TOO obvious until it's in motion (ie can't see evidence in the picture)
d/ the classic "marching ants" - poor comb filtering of the composite video data either in the camera or (more likely) the capture card. There are digital filters (eg for Avisynth) that are made specifically to get rid of bad examples of this effect. However they usually manifest on digital graphics/text/logos, greenscreening and high-moire fabrics more than everyday recordings, otherwise most colour broadcasts would be unwatchable...

Could you at least make e.g. a 10 frame sequence from an example scene, where the camera is as still as possible, and upload them all? (or 5-6 frames in a full rez animated gif) --- when it's moving, it'll be pretty obvious which of the above it is.