Interlace and Non-Interlace Recordings

[Mike65]

I have been playing around with the video-in function with on my Leadtek GeForce 4 TI card trying to capture video from the TV. I have been using VirtualDub for the capturing because I feel that it's the best and most flexible out there. I am only playing around with video capture and don't intend to rip TV shows for others.

It seems to work fine when I use 352x288 for the resolution and I don't get any interlace lines that looks dreadful. The problem arises when I go higher than e.g. 640x480 or 720x576. I get interlace lines but the weird thing is not all the time. I could be recording part of a TV show, stop it and test it and the video looks fine then if I start it back up the lines may appear. I have used several compressors including Huffyuv, DivX, XviD etc. when ripping including no recompression. It seems to be a matter of luck if I get these lines or not. I have used the de-interlace filter in VirtualDub but it doesn't give the best results, the blend filter does what it says it blends the interlace lines and moving objects looks awful. The duplicate one makes the image look jagged, discard halves the vertical image which I don't want because I want to keep a high resolution. I have used the de-interlace function in DivX too but that makes the image slightly jagged. I want to try and get the ripping on the show when the interlace lines don't appear in the first place because the image looks great but I don't want the unpredictability of what I am getting at the moment. How do I turn interlace off?

Is there anyway to get around this problem? Has anyone else had this problem and found a way to fix it? I appreciate any replies. Note I live in England and use the PAL system if that makes any difference.

[Mike65]

Sorry I've found out the problem why sometimes it seems like the video is interlaced and other times its not. It's because there's something called field shifting that was happening. After reading a site called http://www.lukesvideo.com/ which I found the link for it in another topic in this forum I used a filter called telecide and the problem was fixed and the image doesn't degrade either.

[bunyip]

That's interesting, I'm always looking for better ways to handle interlacing.

At what point did you apply the telecide filter? was it during the capture or at encoding time, say from AVI to MPEG for example?