JES Deinterlacer Question

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Level 2

271 points

JES Deinterlacer Question

I've been using JES Deinterlacer to deinterlace my DV files before I export them as MPEG4. (by the way, is QT SUPPOSED to do this? ..I hope it's just a bug than needs to be fixed)

There is a box/slider that says "Block Match Threshold". I read through the readme, but I can't figure exactly what this does? It was originally set to 600, but when I deinterlaced some of the files I noticed there were some interlace fragments that keep popping up and they look kind of ugly. So I set it to 0, and that seems to fix my problem. What exactly is it doing? I know it says something about being an exact block match, but I don't know if that's good or not. I would assume if it was the best setting that it would be the default setting.

I just want to know if I'm making a mistake by setting that box to 0

EDIT: Just popped back out to the main page and noticed this was the 1,000th topic! What's my prize? :P

Posted on Oct 23, 2005 3:53 PM

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Answer 1

Oct 23, 2005 5:36 PM in response to zwei

When deinterlacing it's possible to have it let both fields through if it's deemed that nothing is moving, to try and keep the resolution that was in the interlaced movie. You're able to set the threshhold at which the deinterlacer decides that there is movement, and that it should deinterlace that part of the video. I'm not sure what the scale is, but you don't have to go all the way to 0, some other number might give you better resolution without it being too generous and showing interlace artifacts in areas that just moved a little bit.

What are the dimensions of your MPEG-4 video? If it's 320x240 you might as well deinterlace it without using the automatic features. Leaving in both fields and scaling them down to half size might leave some blurred edges, without really gaining you much detail.

If you have a good reason to be showing MPEG-4 at 640x480, and want more detail, perhaps you should film in progressive mode, like 24p. Then you would get 24 fps that looked really good.

BTW, not everyone want to deinterlace, and so the QuickTime setting is for how the movie plays back. The original file can have both fields in it, and the user can decide if they want to halve the vertical resolution in order to reduce some interlace artifacts when playing on a progressive display.

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Answer 2

zwei Author

Level 2

271 points

Oct 23, 2005 6:04 PM in response to Colin Holgate

I'm exporting at a final resolution of 640x480. Thanks for the description, it makes sense to me now! I will try to give it a low number and see how that works out.

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