When to check off the decomb option?

[kikker]

I have a TV series disc that I'm trying to rebuild. It is clearly a NTSC video DVD. When viewing on my LCD TV, the original DVD clearly has interlacing artifacts. When the DVD is prepared by DVD-RB, the AVS files created for the episodes have the ConverttoYUY set to interlaced=true.

Would it be a good idea to enable decomb in the advanced settings?

Or, is decomb effective only for creating progressive frames from video-based material and/or re-creating the original frames from film-based material?

[jdobbs]

If you're seeing the combing on your LCD TV, I'd definitely enable decombing. It will interpolate to eliminating the comb effect.

It sounds like the original may have been poorly authored. It's possible it was "hard telecined" and that's why you're seeing the combing on an interlaced source. That's is one of the situations where decombing works well.

If you want to blend instead of interpolate to remove the combing, you could also add the "LoadPlugin("path\to\filter)" and "FieldDeinterlace(blend=true)" statements manually using the fillter editor. Very definitely DO NOT attempt to use the Decimate() filter, though (as often done in IVTC).

[kikker]

Ok thanks. As this is a TV series, it's doubtful that any hard-telecining took place, correct? I guess there's no other explanation, as video should not show any sort of combing effects, unless messy progressive frames were at some point constructed.

FieldDeinterlace(blend=true) is much more intensive than a normal decomb, correct? And, if the fields were blended unnecessarily, the end result may be less desirable than if I had chosen simply to decomb, no?

Also, I read somewhere that the intermediate m2v encode is 24p. Would it not be better to deinterlace to 30p? Or, is this a non-issue?

[jdobbs]

Don't worry about the intermediate steps... let DVD-RB take care of that itself. If you attempt to outguess it you will only hurt the outcome. It's only people who know little about the subject that automatically assume it is encoded as progressive. An interlaced 23.976 encode is perfectly legal for an MPEG-2 encode. But, then, it really doesn't matter as the framerate is readjusted back to 29.97 at REBUILD anyhow.

My recommendation would be to simply check the "Decomb" box and let DVD-RB do its magic unimpeded.

BTW, you'll find a lot of TV shows that were originally recorded as FILM.