De-interlacing on a frame-by-frame case?

[PigOnWing]

Hello all,

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First, let me apologize: I wrote on this forum, a long, long time ago, regarding chaptered VCDs and inquiring methods to make them - about the time VCDImager staretd to get the attention of people - got much help from vitalis, and obliged myself to write a 'how-to' regarding XML structure of VCDs.

Then I vanished. Due to various problems, I had trouble accessing the forum, and eventually running my PC, and strode aside generally.

When I came back (equiped with new equipment), I see that this is all rather old news already, as TSCV is taking care of the Chapterin problems these days. But I'm still in debt to vitalis and the rest of the forum members - so please accept my apologies, and I hope I'll still be able to contribute my share..

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I've started doing video capturing recently, and with the help of browsing the site and forum back-and-forth, am trying to get decent capture settings.
I understand I should get better results capturing at full vertical rate (480 for NTSC) and downsizing it later, but am still a bit confused about how to do that, and what should I do in the meanwhile: De-interlace using VirtualDub? De-interlace using TMPGEnc's own filter? Which settings? Not de-interlace, and let TMPGEnc do it's own stuff simply when resizing the image to VCD resolution?

But a special case regarding de-interlacing is something I got from a current capture I'm doing, from a poor sourced VHS.
Seems I get 'dropouts' in the picture, sort of 'ghost' images popping every now and then (pretty frequently, actually). I thought 'oh well, poor quality, nothing to do' - but while playing with the de-interlace filters, I've noticed that usually these dropout occure only in one field and not the other. That is, if I de-interlace not by using 'Blend' but by duplicating the fields, I get rid of these 'ghosts'.

- But -
These ghosts don't all appear in "fields A", of course. Some are A, some are B

If you have the strength for it, I'm including links to actual file samples.
All files are 2.5MB in size, 480x480, 1150Kbps (I know it's neither VCD nor SVCD compliant. It's testing.)

First, http://my.magicpage.co.il/Music/WillowFarm/GG_-_No_Deinterlace.mpg is what I originally had (Well, MPG compressed, of course, but still). No deinterlacing involved.
You can see the froupouts at frames 17, 19, 21, 22, 57, 61, 75, 76, 77, 78, 80, 84, 85, 86, 91, 95, 97, 103, 105, 113, 114, 115 (I could go on, but.)

If I apply De-interlacing on even fields, as in http://my.magicpage.co.il/Music/WillowFarm/GG_-_Deinterlace_Even_Fields.mpg, then I'm left with the dropuouts at frames 17, 19, 21, 78, 80, 95 & 97. The rest are gone.

De-interlacing odd fields (http://my.magicpage.co.il/Music/WillowFarm/GG_-_Deinterlace_Even_Fields.mpg) will get dropuouts at the other frames - 22, 57, 61, 75-78, 84-86, 91, 103, 105, 113-114.


So I wonder, if there's a way to tell [either VirtualDub's or TMPGEnc's] de-interlace filter, to use 'duplicate field A' for such and such frames, and 'duplicate field B' for others. As it seems I indeed get best results with the 'Blend' options - when both fields are 'clean', of course' - then specifing this, third option, for the rest of the frames can be wonderful...

But I haven't found anywhere to state 'different filters on different ranges' or such. And especially as what I'm looking for would best be applied at ONE frame at a time.


Any ideas?...

-- Piggie

[kitty]

Welcome back

Does the source use Macrovision? Could it be that varying the picture?

Rather than trying to do correction in encoding maybe some hardware on your capture device (de-macrovision, signal booster, or time base corrector) would clean up your signal into the capture device.

[PigOnWing]

Thanks Kitty,

Nope, I really doubt that a God-knows-what-generation tape of a show taped from TV uses Macrovision protection.

The droupouts are there even when not capturing. It's in the source. Poor, poor source.

[droolian01]

Hi there, i'm not sure but i may have an answer for you.

http://wwwtcs.inf.tu-dresden.de/~dc1/conditional/

This address refers to a virtualdub 'conditional filter', it allows you to "if xxxx elsezzzzzz" type stuff. (as u can see i am crap at computers)

You may be able to selectively test for data in either field, then either blend, duplicate a or b or whatever.

Hope this helps.
(if my link actually works i'll be amazed!)

[droolian01]

woo hoo, i'm amazed!

[PigOnWing]

droolian01 -

I've only had a glance at the text on the link you supplied, and I think it actually is exactly what I'm looking for!

I'll have a go at it in an hour or so. Many, many thanks!

(Now all I need is an auto-eye filter, to go through the file and spot all the different frame-cases, make a list, run it, and prepare me some coffee, two sugar, blended, not stirred, thank you).

-- Piggie