I finally figured out my 4:3 to 16:9 conversion problem

Laurence wrote on 4/1/2005, 1:30 PM
I just figured this out:

If you are using interlaced footage and you go from 4:3 to 16:9 interlaced using Ultimate S, Celluloid or doing the settings manually in Vegas, you need to have the deinterlace method in the project properties set to either "blend fields" or "interpolate". Otherwise the interlace pattern will be resized and you will get horrible looking squiggley vertical lines any time there is motion.

I've made several posts in frustration the last couple of months about how when I go from 4:3 to 16:9 in Vegas I get wavy vertical lines from the interlace pattern being resized. What was so frustrating is that when I first got Ultimate-S it worked perfectly. Then it stopped working and I could no longer change aspect ratios without wormy looking squigley vertical lines every time there was any movement. For a while I was convinced that it was a Vegas 5.0d bug because when I downgraded to an earlier version of Vegas it worked properly again. Then I tried changing aspect ratios again and had the same problem even with the earlier version.

Anyway, I finally figured out what was wrong. In the project properties I had changed the deinterlace method from "blend fields" to "none". It turns out that even though the footage is interlaced both before and after the aspect ratio conversion, deinterlacing is part of the resizing process. I experimented and find that both "blend fields" and "interpolate" work equally well. I did test renders both ways and cannot see any difference. If you set the deinterlace method to "none" though, boy does it look awful.

There were some posts about wormy looking vertical lines on HD to SD resizes and I'll bet it is the same problem. Evidently the deinterlace method is important for more than just deinterlacing! Anyway, my problem is solved and I'm back on the latest version of Vegas and all is well.

Comments

Laurence wrote on 4/4/2005, 12:32 PM
I'm sort of surprised nobody has chimed in here. I can't be the only one who has run into this.
mel58i wrote on 4/4/2005, 1:35 PM
Hi friend,
Yep I had the same problem with the sawtooth verticals on movement when going to 16:9. And yes I had to do the same thing in properties by setting blend or interpolate fields (found the former slightly better). I believe vegas has to seperate the two fields in this process and that's why you have to specify how to combine them again.

Mel.
Laurence wrote on 4/4/2005, 8:48 PM
The thing that sort of surprises me is that when you go from 4:3 to 16:9 with the deinterlace method set to "blend fields" or "Interpolate", the 16:9 converted footage is still interlaced. If you view it on an external monitor at full sized best resolution, you can see motion images jumping positions just like you could before the resize. If you do the same conversion with the deinterlace method set to "none", you get resized interlace lines which look wormy and horrible.

Evidently Vegas looks at these settings to decide if the footage is interlaced or not, and resizes differently depending on this setting. If a deinterlace method is selected it must do something like a typical VirtualDub "separate into fields / resize / then recombine fields" instead of just a plain old resize. When I tried several experiments with this, the "blend fields" and "interpolate" methods looked exactly the same.

I don't think that either method of deinterlace is actually happening in this conversion. It's just using this setting as a flag in order to determine whether to do a regular resize or a separated field resize.
Laurence wrote on 4/8/2005, 6:17 AM
Bump
apit34356 wrote on 4/8/2005, 6:50 AM
Bump,

??? Are you wanting a more "fixed" method of conv from 4:3# to 16:9 or for Sony to have presets to chose from???
apit34356 wrote on 4/8/2005, 7:25 AM
Sony, please lock this thread, 4:3 is not getting along with 16:9....... hooo no, PAL jumping in..... PAL just punched 525 in the "resolution", 525 just called PAL "euro trash",..... 16:9 just pull out a set of black bars and is beating up 4:3 with them........ 1080i just can in and started beating up PAL and 16:9 for picking on the old 525. Its getting really bloody, with compression wounds, bad formatting,......... Please Sony, stop the.......... I can't ook any more....... well maybe, just till 1080p shows up.....
farss wrote on 4/8/2005, 7:58 AM
You are not allowed to mention 1080p on a Sony forum. Such a thing does not exist despite what all that Eurotrash might try to tell you.
apit34356 wrote on 4/8/2005, 9:22 AM
oh, I should have said the " other 1080", with real muscles and likes expresso!