Question about interlace problem

[jimdagys]

I've got the original mpg, and then I used Virtual Dubmod to compress to avi. If I play in vlc and choose "video/deinterlace/blend" that improves the situation, but I was wondering if there is a setting in Virtual dubmod that can improve the interlacing when I compress/convert to avi.
See the video clips:
1) mpg
2 avi

[manono]

You can blend deinterlace from within VDubMod, but it's still a lousy way to deinterlace as it makes all movement blended/blurry.

[davexnet]

Why not use the regular Virtualdub? At least that has yadif.

[jagabo]

There's something wrong with that fields in that MPG sample. You have more than just an interlace video issue.

[jimdagys]

Don't know how to use yadif.
I got the original mpg (home video) that was 1.5 hours long and I used Video Redo to cut it down to 9 minutes.
Then I put it through Virtual Dubmod to turn into avi and reduce file size from mpg 450MB to avi 90MB. Overall, for what I am using this video for (teaching English to foreigners), I'm pretty satisfied.
Here is the final 9 minute video (unless I can improve the mpg to avi conversion).
http://www.fileserve.com/file/ZyewrBf
I would like to know what else is wrong with the video (besides interlace problem). I probably can't fix it, but I would like to know anyway.

[davexnet]

There is something wrong in the source, some distortion - I've seen it before, not sure what the cause is.
However it may be acceptable for your classroom situation.

I tried to download the finished AVI, but I couldn't get it to download. Did you resize it to 640*480, to reflect the
true 4:3 aspect ratio? (Not a biggie, but it does look a little more natural that way).

[jagabo]

I suspect the source was 1080i and it was downsized to 480i with a poor, oversharp, resizing algorithm. Unless you can get the original 1080i video and downsize it properly there's probably not a lot you can do except use something like a blend deinterlace on the current video. I don't think Yadif works any better with this video.

[jimdagys]

Thanks for the input on the video. I got the video to download just fine on the above link. I didn't do any resizing.

[jagabo]

The video was mistreated before you got it. mpg.mpg in your first post is not the original video shot by the camera. Or, if it is, it's a really crappy camera!

[jimdagys]

The mpg clip in my first post was a slice of the original video that I got (4.3GB DVD). I used Vob2mpg to extract the mpg and then Video Redo to slice out a piece for the above post. On the original 1.5 hour video, I selected 51 pieces and then used Video Redo to cut and paste the video to 9 minutes. I don't think Video Redo would cause any kind of distortion like you see in the video. As you say, probably poorly compressed to make the DVD.

[jagabo]

It's not poorly compressed. The MPG data on your DVD was poorly prepared. The video was not shot at 720x480. It was shot at a higher resolution and downscaled poorly. Unless you can get hold of a copy of the video before it was mangled there's not much you can do to fix it.

[davexnet]

I did eventually download the AVI video from fileserve. I think it's about the best you can expect,
assuming your source is limited to the DVD you mentioned.

[jimdagys]

It was shot at a higher resolution and downscaled poorly.

For future reference, can you explain something about proper vs poor "downscaling" and what kind of software might be used to do this. Can Virtual Dubmod do this?

[jagabo]

Downscaling interlaced video is a big subject. But VirtualDubMod can easily do better than the MPG sample you provided. VirtualDub can do even better. AviSynth the best.