Question about interlacing

27th Nov 2002 17:23 #1

Member

Hi,

I've been reading a lot on here about interlacing, as I've been trying to capture from VCR's that seem to be "infected" with it. I've basically become resigned to putting up with it, as it seemed that it originated from the video, and wasn't a result of the capture.

Originally, I was capturing at 352x288 using VirtualDub and didn't notice anything, but I wanted to do the capture at 720x576 and VirtualDub wouldn't accept this resolution (or anything above ###x288). I'm using a Pinnacle PCTV and tried updating the drivers to the WDM ones at http://btwincap.sourceforge.net/ but VirtualDub still doesn't like higher res. Next I tried VirtualVCR which works great, and allows me to capture at higher res, but it's now that I notice the interlacing. To be exact, every second frame is clean, and the ones in between are the next and previous interlaced together.

This all seemed to fit with what I'd read about how interlacing dissappears at 288 because every second line is dropped. However I've now just captured at 352x288 using VirtualVCR, and the result contains interlacing. So I'm confused. Why is VirtualVCR giving me interlacing when VirtualDub didn't for the same res. With VirtualDub, it seems that rather than interlacing, each frame is repeated twice, which is what I would have expected if every second line was dropped.

Any help would be greatly appreciated. Thanks. 8)

Quote

27th Nov 2002 23:19 #2

homerpez

Member

If you're capping from NTSC, then 288 will be still too much, you have to resize (or cap) at 240 pixels.

If you do cap at 288 or less (PAL), or 240 or less (NTSC), then theoretically your interlace combing disappears.

I personally cap at as high a res as my setup can take (for me, 480x480 with the huffy codec) Interlace and all. Then I just de-interlace later, or encode to SVCD as Interlaced. 240 pixels high just isn't good enough quality for some material.

As to why V-Dub won't take the larger file? I have no idea...