Use selected fields only.

farss wrote on 5/10/2004, 10:32 PM
Sounds like the last thing any sane man would want to do, throw away half the resolution. But here's the thing. Trying to turn clients video into a DVD I've found that parts of it have what looks like bad interlace artifacts. Except when played back through a TV they're still there and on closer inspection they're much taller than one scan line.
So if I grab a frame into PS and de-interlace one field looks as it should, soft but no artifacts. The other one still has artifacts about 4 or 5 lines high. Needless to say this tends to get worse going through the mpeg encoder.
So I'm thinking maybe a fix for the bad parts is to use only odd fields and live with the drop in vertical res. I've tried using guassian blur with around 0.010 vertical and 0 horizontal but that looks worse than just droping a field.
Anyone know if I can trick Vegas into ditching one field and then interlacing that? Or is this a job for something like VD?

Comments

Grazie wrote on 5/10/2004, 10:39 PM
Interesting! Any chance of sharing your pngs? - G
farss wrote on 5/10/2004, 10:54 PM
Ha!
They should offer me a job on CSI. Working with this client is like being Dick Tracey! She used to use a D8 camera and now I'd bet I know what she did. She had it in "Progressive Scan", which as we all know isn't anything like that.
So I've made it look MUCH better. Render out of Vegas as Progressive with Field Interpolation and voila, almost watchable video.
I'd love to share the pngs but where and how?
Never much into the putting stuff on the web kind of thing.
kevgl wrote on 5/10/2004, 11:07 PM
I can host them if you want ...

Cheers
B_JM wrote on 5/10/2004, 11:29 PM
to seperate fields -- the easest way is with avisynth (which has an easy way to do it) .. almost impossable to do with virtualdub .. though you can use "smart bob" filter on the results to fix the new 60fps up -- or skip this proccess. if you want only the top or bottom field -- use decimate on the 60fps final output and decimate by 2

see here for instructions http://neuron2.net/bob.html
farss wrote on 5/10/2004, 11:54 PM
Well,
converting it to progressive scan has fixed the problem, needed to do it at 'Best' and now it looks 100% OK.
I really don't understand quite how it got the way it is and even less why forcing a field merge in Vegas fixes it up.
I suppose alls well that ends well, I should add that this material was also originally edited in a very early of FCP and the client also admitted she liked playing around with field order (shudder!).
B_JM wrote on 5/11/2004, 6:10 AM
weird that you said it was edited in FCP 1 .. Because I received last week a video edited in FCP 1 and converted to PAL(unknown how) and it had the weirdest black flicker in the interlacing like every 3 frames, one field was black only .. And of course it looked awefull ...

I don't think it was a FCP issue .. but something to do with the onversion or attemp to re-edit in PAL later ...