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View Full Version : capture of pal source, lots of noise, ntsc included


fisix
6th December 2001, 05:18
hows that for a thread subject?

i have a set of videos recorded in pal in england off of a semi bad antenna received bbc channel.

i also have a vcr that internally converts a pal source to ntsc out, though it will also put out pal.

i ALSO have a wintvpvr-pci card. i am almost positive that this card can only capture in ntsc, though every driver seems to allow for pal input. it's hardware limited, right(specific to tuner)?

so, here's the deal. i want to capture the video to disk, and then do my best using filters and such to get the end result in a reasonably compressed divx. actually, i'm going mostly for quality, so possibly one 30min show/cd is ok. if it looks good at that point, i can compress more as desired.

the hitch is that i have only used filters to make cartoons look good, and my first couple tries at real-life capture looked pretty bad (star trek).

i need some starting points... like how best to capture the video, and then some good filters to use, and some ideas on what might happen with this pal->ntsc->?? cluster-f i'm proposing.

my first try is going to be to treat the video as pure ntsc, but i'm willing to bet it's going to look crappy initially.

at the very least, can someone offer suggestions on noise filters for real-life noisy video?

oops, i almost forgot. i'll be capturing using vdub->huffy at first, then using nandub to apply the filters and 2pass divx encode.

i hope steady reads this, and cart, i'm going to search your forum and website for insight as well.

thanks
-fisix

hakko504
6th December 2001, 07:13
I'm not familiar with the card in question (winTV) but it is likely that it has a CVBS input. This way you can skip the tuner thus enabling direct PAL capture. This of course requires that the VCR has a corresponding output. (Or instead of CVBS there is also the possibility of a S-video connector)

charlesky
6th December 2001, 13:06
Every capture chip I've seen can handle both PAL and NTSC as long as the drivers supply the correct parameters, so you won't have any problem feeding PAL video to your capture card. I'd recommend you set your VCR to output pure PAL video and capture that, as it bypasses any conversion stuff which will degrade quality. You'll be connecting to your VCR using a composite video connection, so the tuner (if your card has one) doesn't matter.

As far as filters go, it really depends on what the picture looks like. If the problem is just a weak video signal causing noise in the picture, you can try a mixture of temporal cleaner and smoother. If you have ghost images caused by signal reflections, the jobs a lot tougher. I don't know of any vdub filters that are specifically aimed at cancelling ghost images, but you'd want to take a high-contrast edge-enhanced copy of the frame, shift it to the right by the same amount as your ghost and then subtract it from the original's luminance.

fisix
7th December 2001, 09:30
thanks for the replies. you know, i should have remembered that my card has an svideo and composit in.. it should be very interesting to see how easy it's going to be to actually capture at pal. lots of things to change in vdub.

charlsky: good idea on the ghost image, but not the problem. temporal cleaner and smoother tend to posterize the video, but i'll play with the settings more. has anyone actually coded up a ghost image filter? i'll check the vdub filter sites (just for fun).

-fisix

tenebrenz
7th December 2001, 21:34
there is a ghost reduction filter in tmpgenc.

Cart
21st December 2001, 23:38
Another ghost reduction filter is here:
http://republika.pl/vander74/virtualdub/index.html

Real-life video is quite a bit more tricky than cartoon video when it comes to noise reduction. I think you're headed in the right direction though. A temporal and a spatial smoother with tuned, not-too-strong settings is a good way to go.

-Cart
http://www.geocities.com/lukesvideo/index.html