What are the horizontal lines on computer viewed mpeg2?

[Steve Mackay]

I just converted my AVI to mpeg2. When I view the .avi file on my computer it looks fantastic. When I view the mpeg2 video on my computer it has horizontal lines on it. I read in a post below this could be because of interlacing. Computer screens apparently have no interlacing (progressive scan?) where as my mpeg2 is interlaced. When burned to DVD and played on my TV it looks pretty good, much better than the computer. I'm almost happy with the quality but I think I can still see those horizontal lines. (it may be in my head though!)

If it is interlacing causing the horizontal lines on my computer why does it not look like this when I view a rented DVD movie on my computer?

I'm a little concerned about this as I have a progressive scan video camera. Sometimes I film with progressive scan, sometimes not. I edit my video with Adobe Premier 6.5 and thought that the output .avi would be all interlaced (not mixed like the captured .avi). However seeing those lines on my computer screen makes me wonder.

Is there a way to tell if my .avi is interlaced or not?

I have some software that tells frame rate and resolution but i do not think it tells me if it is interlaced or not.

Advice appreciated.

Thanks

Steve

[Gazorgan]

It's interlacing effects. View it in PowerDVD to eliminate the problem.

VDUB will tell you if it's interlaced or not. Generally speaking AVI's aren't interlaced. Only DivX 5.0.5 or better support it, everything else is progressive.

DV cam footage is the exception, it is interlaced. However, the fields are usually reversed. If you have interlacing/choppy effects on your DVD, try encoding with reversed fields.

[MYoung]

It should be obvious just by opening the file in VDub if it is interlaced or not. What software DVD players do is deinterlace the interlaced video. If it is film-based content or progressive video (like movies), then the software does 3:2 pulldown (a.k.a. inverse telecine -- IVTC) and reconstructs progressive frames from the interlaced frames. It goes from interlaced video at 29.97 fps to progressive video at 23.976 fps.

[Steve Mackay]

I thought I had viewed my DVD using powerDVD. Anyway I've just tried viewing it again in powerDVD and it still shows the horizontal lines.

When I opened it in VirtualDub it was showing 29.97 fps so I presume it is an interlaced file.

The link below should take you to two images of what I am talking about. Look at the paddle. It is pretty much like this through the whole video.

http://www.boatertalk.com/gallery.php?imageid=767

http://www.boatertalk.com/gallery.php?imageid=768

Help appreciated

[Steve Mackay]

Note the above pictures are captured as I was playing the movie in power DVD.

[tito13kfm]

Those really don't look like interlace lines to me. It really looks like an improper field order to me.. but then again i'd have to see it in motion to be absolutley certain. Plus if those were taken in PowerDVD then the interlacing would not show (it uses a technique called Bob and Weave, I believe, in order to blend the fields together properly.)

[Barnabas]

Burn it to a DVD or CD. If it shakes when there is sideways horizontal movement, it's the wrong field order.

[Steve Mackay]

I did burn it to a DVD and that is a screen capture from playing the DVD with PowerDVD.

I also re-exported a short section of the film from premier again last night and reversed the field order. It did not seem to make a difference, although I've not burned that clip to DVD yet.

Steve

[Barnabas]

On one of my capture cards, if I change it from the default filed order when capturing, the file is messed up and looks like that. At that point it is no longer repairable, so you may need to capture it again. You can also try to use TMPGEnc to encode the AVI file and have it merge the interlaced file and see how that works.