De-Interlacing

Movick wrote on 6/10/2006, 11:57 PM
I’ve been working with some digital signage broadcasting where rendered MPEG 4 video clips are scheduled in play-loops, uploaded to a server, then a remote site media player PC queries the server, uploads the play-loop, and plays the content back on 1360 X 768 LCD flat-screen TVs.
Because the content will be played back from a dedicated PC to an LCD screen via VGA cables, I have to eliminate the video interlacing from the content for optimal play. Can someone suggest the best method to render MPEG 4 video without it being interlaced? Can I do this in VV6, or must I de-interlace the DV source video first? I currently use a Sony PD-150 for acquisition - primarily straight DV, very occasionally DV-CAM.
Any help will be tremendously appreciated.

Thanks,

Movick

Comments

Chienworks wrote on 6/11/2006, 3:06 AM
I've been producing a lot of non-interlaced clips from DV material lately. All i can say is Vegas' deinterlacing when rendering is phenomenal. I choose a field order of "none" under custom settings when rendering and the results are almost always fantastic. About the only thing it can't handle is horizontal motion so fast that it's a blur anyway.
apit34356 wrote on 6/11/2006, 5:06 AM
Chienworks, let me understand your work flow,...., you edit in vegas standard dv 60i, add titles, FX,..etc... then when rendering, choose "custom setting", field order "none". for 30p or 60p?
Chienworks wrote on 6/11/2006, 6:03 AM
Correct. Well, for 30p anyway. I've never tried 60p.
farss wrote on 6/11/2006, 7:03 AM
Let me see if I've got this right.
You start with 60i, De-Interlace method set to None and just render to 30p and it looks OK?
I'd assume in that scenario Vegas would combine the two fields into one frame (same as Blend) and you should see pretty bad interlace artifacts on motion.

Bob.
Chienworks wrote on 6/11/2006, 11:02 AM
Doing some checking .... according to the properties window the Deinterlace method is set to Blend fields. That must be the default because i've never changed it. Looking at a few output files i see that rendering to 29.97p DV i can still see some interlacing, but when viewing on a computer monitor it's no where near as bad as watching the original 59.94i DV file. When rendering to 29.97p MPEG the interlacing artifacts are almost nonexistant. I've tried some stuff where the interlace combing was over 20 pixels wide and in the progressive MPEG version it isn't noticeable at all. *shrug* Vegas is doing it, not me.
Movick wrote on 6/11/2006, 10:07 PM
Chienworks,

Thanks as always for the tips. Let me verify what I believe I should do:
In the Project Properties Box, I should select Field Order as "None Progressive Scan" , for Deinterlace Method, select ”Blend Fields”, and when rendering, use the Custom button, select the “Video” tab and select “Progressive Only’ from the Field Order drop-down list. Is this correct?

Thanks,

Movick
DJPadre wrote on 6/12/2006, 3:50 AM
hmm.. blending.. i dunno... the fact that your literally drawing in new frames, i would actually recomend to Interpolate the flields... To my eye (and to my tvs, monitors and HD panels) its much cleaner during motion without any combing. Add some sharpness to ur project FX and the softness you get from interpolation will magically disapper.. but wait theres more.. u also get a set of steak knives and a bagless vacuum cleaner... oh sorry, wrong ad..
Chienworks wrote on 6/12/2006, 5:53 AM
Movick, yes, but there's no need to set the project properties to progressive. You can if you want to, but it's totally wasted mouse clicks. Project properties are completely overridden by render settings. In other words, at render time project properties are meaningless and ignored.
craftech wrote on 6/12/2006, 6:55 AM
Kelly,

How bad is the motion blur? Are we talking about little or no lateral movement for it not to be noticeable? Can you give an example (analogy)?

John
NickHope wrote on 7/13/2006, 9:36 AM
Chienworks, you are mostly right but the "deinterlace method" in project properties is used at render time. There is nowhere else to set the deinterlace method (or the motion blur type).

To prove this render to a progressive file from an interlaced source containing big bold moving text and try the 3 settings. You can clearly see the difference when you play the resulting files back in Vegas, especially if you pause playback.

I just thought I would point this out while I'm working on this as it might be misleading.