Amazingly bad judder

NeilPorter wrote on 5/7/2003, 7:47 AM

Hello All,

Firstly, I presume that the word 'judder' has been coined to mean jerky shudder or such. Anyway, I had it really bad. My wife had edited a 1 hour PAL DV tape down to 23 minutes. It was very basic cut'n'paste with a few transitions and/or crossfades, all done on the timeline. She leaves all the technical aspects and other 'difficult' bits to me. So, when the final Print-to-tape had some occasional very juddery scenes, I had to solve it.

I have literally spent weeks and have read several 100s of forum postings to no avail. Render and re-render, print and re-print, the whole veg or just small segments, change this change that ..... nothing!!!

On the way home from work tonight it occurred to me to check the Properties of each individual EVENT - I had already checked the project and render properties many times 'til I was nearly insane. Sure enough, there was the problem - every shuddery scene turned out to be a separate event, randomly found every now and then. The Field Order of each of these was NOT Lower Field First, as it should be. Mostly it was Upper Field First but sometimes it was None (progressive scan). In one case it was NSTC and not PAL. Now, my wife does not even know that interlacing exists, let alone how to change it. This has all been done ACCIDENTALLY!!

Now here's my question:

How is it possible to ACCIDENTALLY change these parameters while just doing basic cutting and pasting on the timeline? Can it be done by accidental key strokes or mouse clicks?

I need to train my wife not to do what she's accidentally done!! :-(

Any suggestions?

Regards,
Neil Porter

Comments

CorporateSound wrote on 5/7/2003, 8:57 AM

I have seen this happen when i used Video Factory, but not in Vegas. Other users had also seen it in VF, but I never heard an answer to why it happened. As you say, it appeared to be random.
You can experiment with changing the event properties, both in the media pool and actually applying it to the file and see if that corrects it.
Before I knew what was causing the problem, I simply replaced the event on the timeline with the same event and it stopped juddering.

mountainman wrote on 5/7/2003, 9:18 AM

NeilPorter, I've had the same thing happen in v4. Mine change to progressive all by themselves. I reported this to sofo but never heard back from them.
win2k, dual athlon. soundblaster, 1 gig ram, NTSC.
JM

Frenchy wrote on 5/7/2003, 9:30 AM

Neil -
Could it be that the field order was changed while grabbing stills from those particular events, and not changed back, or changed to upper field first instead of lower? I've been guilty of the former - ie while grabbing stills, I change the property to progressive (to reduce interlace flicker), and forget (damn that short term memory...)to change it back, I don't know, nor have I heard of a way to *accidentally* change the field order properties...

Frenchy

mikkie wrote on 5/7/2003, 9:41 AM

FWIW...

My take is that when you import a clip into Vegas (or any other NLE), the software takes a look at the file header info to determine stuff like frame size, rate, scan etc... Depending on the source clip and what it's been through prior to the editor, it may not always be recognized correctly. As a matter of course, I generally check this as I'm importing clips to make sure.

As far as how it could get changed, there are a few possibilities IMO. Stuff can get changed accidentally, & I've seen (especially less experienced) users explore things, particularly as they don't always know or remember where everything is. The vegas proj file can become corrupt. PCs are fallable and the software can error.

SonyEPM wrote on 5/7/2003, 11:40 AM

Was a 3rd party app used for capture?

NeilPorter wrote on 5/7/2003, 8:04 PM

I have not used any 3rd party S/W in this. I used the Vegas Video Capture module. There was only one DV tape and the whole lot was captured in one go. It automatically split into scenes. Everything was apparently consistently treated the same way, so that's why it's strange that only the odd scene here and there had some of its parameters changed.

Thanks all for your replies so far.

Regards,
Neil Porter

TorS wrote on 5/8/2003, 2:22 AM

Could field order have been changed in the camera settings between shots or were all the events OK (similar) before they landed on the timeline?
Could there be a discrepancy between the captured format and the project properties, making Vegas guess at the right (wrong) compromise for each event?
Tor

NeilPorter wrote on 5/8/2003, 8:28 AM

Hello Tor and others,

> Could field order have been changed in
> the camera settings between shots
I am fairly sure not so.

> were all the events OK (similar)
> before they landed on the timeline?
Can't prove it bit I am sure. In fact, it seems that one longer scene has had the middle cut out and then the next bit went funny. i.e. it had to be the same type originally.

> Could there be a discrepancy between the
> captured format and the project properties
Not likely - Vegas PAL defaults all the way.

Regards,
Neil Porter

TorS wrote on 5/8/2003, 1:46 PM

Seems very strange.
But when you finally have discovered the odd field order, I assume you've changed it and rerendered - is it OK now? Perhaps your wife should do another edit and see if there is something in her working procedures that can cause such a thing. When things are the way you say they are it's hard to figure how Vegas can cause them on its own.
Tor