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View Full Version : DVE's don't go to edges in underscan



maddogmike
05-04-2004, 03:54 PM
I have several irises and wipes in the project I'm working on. When I finally exported the thing to DVD, I noticed that my transitions are funky at the edges. Nothing you'd notice on a regular TV monitor (it's outside TV cut-off), but if you're watching a the DVD on a computer (or possibly video projection) there's problems.

Once I saw what was happening, I clicked on the underscan in TED and saw that it's like that in the original project.

The irises don't extend all the way to the left. There's a band along the edge that isn't black -- you can see right through to the clip underneath. Similarly, the wipes don't extend to the edge all the way around.

So is there a way to stretch the DVE's? Or change their dimensions? I want them to be 720 by 480, like my clips. I don't know what they are now, but it's considerably less.

Jim Capillo
05-04-2004, 04:23 PM
Same thing if you encode for the web.......:eek: :confused:

ScorpioProd
05-04-2004, 08:36 PM
This is how it's always been.

The VT was designed for TV, with its very forgiving overscan area.

Until the DVE engine is eventually rewritten, I don't know of any fix for the problem.

The only workaround is to mask out the edges when you encode your video, like inside of TMPGEnc, for instance. (Remember to MASK and not crop, or you will introduce scaling artifacts. Of course, if you are using the TMPGEnc plug-in or AVI Wrapper, you may have to crop to correct the 486 lines to 480 lines, and you can't do both at once.)

bradl
05-05-2004, 07:31 AM
You hit a hot button with me on this! Here goes...

There are DVE's that are worse than others. Some are older and have not been re-built for 486 so there are 6 additonal lines missing. Regardless of old or newer, the DVE creation kit and instructions include a Clipping mask which remove about 5 pixels from every edge. The reason, I suppose, was to remove the black edges as a source moves across or through the scene.

Traditionally, on-line linear editors kept a close eye on 'blanking' and minimized the effect and problems in a more un-noticable way. For instance, start your DVE move, about 5% in do a crop if needed to hide the black, or just before it was coming to full screen you remove the crop. If done right, you don't even notice even when watching 'underscan'. Somewhere along the line at Newtek, they decided the approach should be don't worry about overscan, you can't see it normally anyway. Bad decision then, and now it is really biting us in the 'multi-media' age.

You can create your own DVE's with Lightwave or Aura and not have this cropping happen. That is what we have done. In fact the cropping trick I mention from linear days is exactly what I do in LW or Aura. If an image never leaves FS, a traditional 'wipe' for instance, you don't need to clip the edge at all, so we don't. Many of my wipes and DVE moves have given to Newtek and they should be included in the next major release.

Lastly, and one of my on going complaints, is the fact that turning 'overlay' on will in itself cause edge clipping and shows through to layers underneath. Again the idea was to remove unwanted black, I suppose, but with the Spline Nodes and Cropping tools, it is not needed. I fight with it evey day. When i really bothers me, I increase the size of the overlay layer to compensate, giving up slight resolution and machine performance, however.

maddogmike
05-06-2004, 02:06 PM
This is a bummer. Hopefully I'll be able to create some DVE's with Aura, but I find that program really frustrating. Any tutorials you can point me towards?

tmon
05-06-2004, 03:05 PM
IMHO, regardless of whether NewTek chooses to focus on the event videographer, live switch production crowd or the post-house type pro editor, it is true that more video production today ends up being seen via projector, webcast or streaming, and not a traditional overscan delivery.

Therefore, an investment to correct this issue is in order. The in-house engineers can correct the software issues. As for correcting the DVE's, my suggestion: Hire a talented LightWaver on a contract/job basis and redo 'em!

bradl
05-06-2004, 03:26 PM
Originally posted by maddogmike
...Hopefully I'll be able to create some DVE's with Aura, but I find that program really frustrating. Any tutorials you can point me towards? There is a thread going that has lots of good info:
Making A Pointed Wipe DVE (http://vbulletin.newtek.com/showthread.php?s=&threadid=22051) and I believe it is discussed at Bauhaus Forums as well. The DVE creation is remarkably simple in Aura. Read the Tutorial, then try it. You will see. You can make basic wipes in minutes, but for the real fancy DVE with warp 3D look you will have to turn to Lightwave which is quite a bit more complicated to produce an actual working decent looking DVE. Mostly look around the net and get some created by others, like VT Knowledge (http://www.vtknowledge.com/)

Generally, I feel, fancy DVE's and wipes can really be distracting from your message. We use them some but I prefer custom effects, natural wipes, and about 90% of the time Dissolves. Additionally, I end up with almost everything in Overlay mode, so I can't use any to the DVE's anyway. Have to render a section usually to use one and it is not worth it most of the time.

The is a PDF that came with the Aura VT Wipe Builder that is very helpful. You can get it on the Newtek FTP server at:
ftp://ftp.newtek.com/pub/VideoToaster/Downloads/VTWipeBuilder.pdf


Here some links to Aura Tutorials:

Aura DVE Builder
http://www.vtknowledge.com/index.php?action=viewtutorial&id=Aura%20DVE%20Builder

Newtek Aura Tutorials
http://www.newtek.com/products/vt/aura/tutorials/index.html

Aura Getting Started Tutorials
http://www.newtek.com/products/vt/aura/tutorials/getting_started.html

Don Ballance Aura Tutorials
http://www.newtek.com/products/vt/aura/tutorials/db_tuts.html

Converting Alpha Wipes to Realtime T2 DVEs With AuraVT
http://www.newtekpro.com/AuraInsider/aura/articles/alphawipes/alpha_tut.html

deandec
05-06-2004, 03:52 PM
It's this kind of thing that makes me not do effects work with the Toaster. As soon as I click overlay on there is a bunch of scanlines lost top and bottom. What gives? I always work in underscan and don't want to see some layer below the top creeping through on the top and bottom of the frame. Is Newtek going to deal with this?

maddogmike
05-07-2004, 12:36 PM
Thanks for all the links, Brad. That should get me going on the right track.

mgrusin
05-08-2004, 09:29 PM
I know that media players show discrete content edge-to-edge, but correct me if I'm wrong - shouldn't even PC-based DVD playback software respect the overscan area? Otherwise you'd be seeing all kinds of boom mics, flags, etc. on your Hollywood DVDs...

I don't like junk in the overscan either, but really, you should never see it. The only time this comes up for me is if I'm packaging a file for computer or web playback through one of those media players that shows edge-to-edge. In these cases I always crop for mask in the encoder to get rid of the overscan, not so much because of the glitches, but because I didn't compose my shots for overscan in the first place.

-MG.

deandec
05-09-2004, 07:59 AM
I get a hard time about it when I send stuff to other post houses to finish or whatever. The editor calls and says "what's that stuff outside safety"? And just about every time my client is sitting there with him. It's just a perception I know but not a good one. Also I have to crop it out when I send web based tests. Which I do often. Is it really that big a deal to fix it? Newtek?

ScorpioProd
05-09-2004, 11:29 PM
I've never seen a software DVD player that didn't show edge to edge.

mgrusin
05-20-2004, 12:08 PM
I've never seen a software DVD player that didn't show edge to edge.
You got me thinking, so I tried my software player with a scene I know of in Edward Scissorhands where a big flag shows up in overscan, and you're absolutely right (not that I doubted you ;) ). The player does indeed show edge to edge, and at least in mine I could find no preference item to "clip overscan" etc.

I'm disappointed - from time to time I've been a projectionist so I've been taught how important proper framing is, and I've always respected the safe area in video. Now I see that this is being ignored by an increasingly popular method of delivery, not to mention the realization that software players have wholly different framing than hardware players... :eek: Oh well. :rolleyes:

Thanks for the correction Eugene! -MG.