Virtualdub processing on noisy VHS - 2 questions

[qlizard]

I have bad VHS sources that have a lot of noise which I'd like to clean up before converting to DVD. I have a VCR w/ TBC built in and a stand-alone TBC with color correction, etc. But even with correcting there is a lot of noise.

I'm going to filter in Vdub, but I've seen varying recommendations regarding deinterlacing before the filter chain. Since the final product will be interlaced, should I just leave it alone and filter, or deinterlace, filter, then reinterlace? If it makes a difference, I'm NTSC.

Second, does anybody use the MSU noise filters? They look pretty good but are they better than the standard noise reducers (I use the static and dynamic noise filters).

[Steen4]

First off, what is the destination format of your video? If you are going for vcd, then, by all means, de-interlace! Two good de-interlacers to consider are the smart deinterlacer (Don Graft) and the area-based deinterlacer (Gunnar Thalin). I like the area-based version better, but this is merely a personal bias, so experiment and judge the results for yourself. You should also check your source video for recurring patterns of 3 full frames followed by two interlaced, or 'combed' frames. I call them combed because you will see "comb lines" in areas of movement, especially when it's side-to-side movement. If you see this pattern, then you could skip deinterlacing and perform an inverse telecine on the source. It's FAR better than deinterlacing because it restores 29.97 telecined video to its original 23.976 full frame form. There are several websites which explain the benefits of ivtc and will explain how to perform the procedure. Finally, if you intend to create cvd/svcd files or dvd-video, it's best not to fool around with deinterlacing at all, unless it's an ivtc conversion. After all, though, ivtc is just an option, not a necessity at full 480 resolution, so it really depends on how much hassle you feel you're up for.

[codecpage]

The good noise reduction filters all work in the time domain rather than in the area. There it is absolutely unnecessary to worry about interlacing effects.
Some more filtering hints here: http://www.codecpage.com/DVD.html#Anker113798

Cheers

[Steen4]

Actually, codecpage, there is usually a need for deinterlacing if his destination format is vcd. He will either be capturing at ???x240, in which case he will not need to interlace only because he is losing half of his video information, or he will be resizing from ???x480, in which case his video output will depend on the default resizing method of the program he uses to create his resized video if he does not take matters into his own hands. The main need for deinterlacing arises from the fact that the vcd spec cannot support interlaced video at 240 lines, but simply capping at 240 means that your capture card/device is throwing away 240 lines of information. Capping at ???x480, then deinterlacing (using your preferred method) and resizing ensures a result of the user's choosing as well as including all video information is represented (well, represented as accurately as 240 lines can).

[LabanB]

Steen4,

He clearly states the destination is DVD, so does this change the need to deinterlace?

Bill

[qlizard]

The good noise reduction filters all work in the time domain rather than in the area. There it is absolutely unnecessary to worry about interlacing effects.
Some more filtering hints here: http://www.codecpage.com/DVD.html#Anker113798

Thanks for the info and the link. That is good reading.
Yes, my destination is DVD and I am capturing through my DV camcorder at 720x480. So it appears the consensus at least for full resolution is to not deinterlace. And I'm going to try that temporal smoother out.
thanks

[Steen4]

qlizard wrote:

I have bad VHS sources that have a lot of noise which I'd like to clean up before converting to DVD.

Boy, am I an attentive reader!

I have no idea why I thought he just wanted to play it back on his dvd player.