How to tell Interlaced from Progressive?

[KillerBear]

What is the best way to know if your AVI (or any other format for that matter) is interlaced or progressive?
If it is interlaced, what is the best way to de-interlace?
Thanks...

[Baldrick]

read
www.digitalfaq.com/dvdguides/capture/understandsource.htm#interlace
and
www.100fps.com

[junkmalle]

Open your file with VirtualDubMPEG2 or VirtualDubMod. Step through frames where anything is moving. If you see no comb lines you have progressive. If you see comb lines you have interlace. If you see a pattern of three frames without comb lines, two with, then you have telecined video.

Don't trust any software to tell you. Software often makes mistakes. And be careful using media player programs -- many of them will deinterlace automatically for display on the computer monitor so you won't be able to tell.

The best way to deinterlace is not to. If your camcorder has a progessive mode, use it. If you just want to watch your interlaced video on TV, leave the video interlaced. On the computer use a media player which deinterlaces on-the-fly.

If you really must deinterlace, for telecined film the best method is to inverse telecine (but you have to know what you're doing). For truely interlaced material (like live sporting events, camcorder footage, etc.) the best method varies depending on the material, what kind of artifacts you prefer (all methods of deinterlacing are destructive), and what your final output device is.

For low motion video a blend deinterlace might work best (maybe with a sharpen filter afterwards). For high motion material on a progressive display a BOB deinterlace may be appropriate. Or you may prefer one of the smart deinteralce filters, or even a drop field deinterlace.

[SLK001]

The only time to deinterlace is when a progressive source is telecined for display on a broadcast NTSC TV system. Then, preform an InverseTelecine on the video. For every other interlaced source it is best to not deinterlace, since the various fields are temporally unique, and any deinterlace would be discarding data.

What is your source?

[Su-Fi_Brett]

Maybe this is obscure, but I couldn't open my MPG2 encoded video in ANYTHING... I needed to convert it to something smaller.. compressed with DIVX. But I was getting so frustrated with VirtualDub because it wouldn't open the video.

Thanks to junkmalle for pointing out the special build of VirtualDubMPG2, it works! And it works oh so well.

THANK YOU SO MUCH!!!

[junkmalle]

Su-Fi_Brett, Glad to help out. It sounds like you don't have an MPEG2 codec on your system. VirtualDubMPEG2 has it's own MPEG2 decoder built in, but many other programs need an external codec.

Windows includes an MPEG1 decoder but not an MPEG2 decoder. You can find a few free ones in the tools section.