Subtle, yet major, bug in Vegas

John_Cline wrote on 5/3/2003, 2:54 PM
This is a weird one and will stop me from using Vegas until it is resolved. I am running Vegas v4.0b.

I have an animation that is 20 seconds long. This particular clip was generated with After Effects as an uncompressed 29.970 interlaced AVI. I place it on the timeline in Vegas and step through it and at exactly 2 seconds 28 frames into the clip, it will repeat that frame for one frame and then continue. The frames at 2:28 and 2:29 are identical. After Effects, Premiere, Virtual Dub and Avid XpressDV DO NOT exhibit this problem when viewing or playing this file. There is absolutely nothing wrong with the clip, the frame rate, dimensions and the field dominance are set correctly, something in Vegas is causing this.

It doesn't matter where I place the clip on the timeline in Vegas or if I trim the head, it will occur at exactly 2:28 into the actual clip. I went back and discovered that it doesn't just happen on this one particular clip. I have a lot of other animations that I have generated in various programs and they ALL exhibit this problem and ONLY in Vegas. If I step through it on the timeline or render it out to a file, Vegas places the repeated frame in the file and it will stutter for a frame when playing the Vegas-generated DV file in anything else.

I just got back from visiting several of my friends who are also running Vegas and the problem happens on their machines as well. This appears to be a subtle, yet serious, bug in Vegas.

Curiously, the duplicated frame does not seem to occur on captured clips.



Brazilian wrote on 5/3/2003, 3:59 PM
I just did this test and came up with the same results.

I actually also dragged a captured DV clip onto the timeline and stepped through it and had the same results, which is not good. All of the framerates of the project and media match.

However, with clips at 29.97, if I change the Vegas project to 30fps, everything seems to work fine. Hmmm.. that ain't right.
BillyBoy wrote on 5/3/2003, 4:12 PM
What am I missing... if you have a clip running at 29.97 (30 frames a second) at two seconds, you should be at frame 60 not frame 28.

Does it happen EVERY 28 seconds over and over if the clip is longer? If so, this sounds like it is related to rounding. Why, I haven't a clue.
SonyDennis wrote on 5/3/2003, 5:22 PM

On not on a machine with AE installed, but why do you blame Vegas? I'm willing to bet the clip is marked 29.97 fps (exactly) which would be incorrect. NTSC video runs at 30,000/1,001 fps (29.97002997002997...). If you put 29.97 (exact) on the timeline, it's going to slip a frame somewhere. It would be nice if Adobe fixed their bug.

John_Cline wrote on 5/3/2003, 5:26 PM
Billy Boy,

It happens at 2 seconds 28 frames. Or to put it another way, the 28th frame of second number two, or another way, 88 frames. The 88th and 89th frame are identical because frame 88 gets repeated at frame 89. I have spent the entire day testing this out with various video software and it's only a problem in Vegas.


I said the particular file that brought this to my attention was generated in AE. Other files I tested, which exhibited this problem, were generated in programs other than Adobe products. The reason that I blame Vegas is that it is the only program that shows this behavior.

vicmilt wrote on 5/3/2003, 5:33 PM
Just out of curiousity... what difference does one frame every 88 frames make to you?
Not so long ago, when we were doing all production in film (well, not so long ago to me), it often became necessary to pop in a "black frame" to make up some shortfall or other. It wasn't nice, but it was "standard operating procedure". I never got a complaint about an obvious "pop" in any show that this was done in.
A duped frame would be even harder to spot, except by an editor, stepping through the footage.
I love perfection, but this seems a bit harsh, not only on Vegas, but on yourself, that is, absolutely giving up the interface.
Just curious...
John_Cline wrote on 5/3/2003, 5:40 PM

The animation has some quick moves at that instant and it was obvious to everybody that the frame was duplicated. There is a startling "hiccup" at that point and it simply can't be ignored by anyone. I agree that under some other circumstances, a dropped or duplicated frame would go largely undetected, but in this case, it was glaring.

BillyBoy wrote on 5/3/2003, 5:57 PM
John, putting on super critical hat... how good can the animation be if there is to use your words a "startling" hiccup from one frame to the next? That isn't really the fault of the editing application, rather sounds more like the fault of the source file, at least I would blame that in my never humble opinion. <wink>

Animation ie cartoons etc., should be smooth of course. Rounding off we're talking just 1/30th of a second. I would think there shouldn't be anything starling happening in that short a span of time. To fix it, have you tried to add or delete a few frames before so at the point of duplication it isn't so noticeable?

Care to put of a secord or two so forum members can play with it?
Brazilian wrote on 5/3/2003, 6:10 PM
> Just out of curiousity... what difference does one
> frame every 88 frames make to you?


> A duped frame would be even harder to spot, except
> by an editor, stepping through the footage.

You can't be serious.

> On not on a machine with AE installed, but why do
> you blame Vegas?

Dennis: I've stepped through a dozen clips, captured from MiniDV _using_ Vegas, and it's repeating frame 88.

Can anyone else duplicate this?
John_Cline wrote on 5/3/2003, 6:29 PM

It isn't the animation. I've been doing computer animation for video and film since 1987 and I know what works and what doesn't when designing an animation. The file renders and plays PERFECTLY well in every application other than Vegas. It was just the fact that an object in the animation was moving pretty fast at that particular moment and the repeated frame was glaringly obvious. Besides, this is not the only file that exhibits the problem and, as you can read on this thread, I am not the only one seeing this.

BillyBoy wrote on 5/3/2003, 6:45 PM
Nobody said it isn't happening, rather the point is 1/30th of a second? Give me a break. Bug? Maybe. A major bug as you called it? No, in the grand scheme of things hardly, not in my opinion.

I'm sure Dennis can explain it better than I can next time he pops in. I think because we're talking that little fraction 29.97 frames a second as opposed to 30 frames a second. So isn't it necessary to pad it here and there? Isn't that what this is about or am I missing something else?
Brazilian wrote on 5/3/2003, 6:52 PM
Nevermind.. some of the clips I had online were video clips but apparently were compressed to DV from AE. Clips I've just captured from tape through Vegas are OK. It's pretty difficult to tell anything is different when even Vegas rounds it's fps display to 3 decimal places, so everything looks like 29.970 even when it apparently isn't.

However.. while it's great to blame Adobe, what are we supposed to do in the mean time? It doesn't look like there is any way to force-reinterpret clips in Vegas, and the playback speed adjustments don't seem accurate enough to correct for the difference.
bjtap wrote on 5/3/2003, 7:01 PM
FWIW I suggest you follow up on John's point. The reason I say this is because, if I remember correctly, John used to be (or still is) on the Pinnacles DV500 board and he kept on for a loooong time insisting that there was a color problem... and Pinnacles kept on saying no. Well, as it turned out after quite a long battle Pinnacles fixed the problem. I guess I am saying here is that John is very knowledgeable and knows what he is talking about... so please, check it out and don't write it off to an Adobe problem.
Thanks for my 2 cents.
roger_74 wrote on 5/3/2003, 7:20 PM
I got a duplicate at 88-89 too on a 20 second clip. But it's strange, if I make a ten second clip there a no duplicates even though 88-89 are well within the ten seconds.

Also, if I render a clip in Vegas and then resave it in Virtual Dub, the clip is still ok. However, if I open a clip rendered with After Effects in Virtual Dub it does not have any duplicates, and if I resave in Virtual Dub it still won't be correct in Vegas.
HPV wrote on 5/3/2003, 10:26 PM
Wasn't this covered here some time ago? Wasn't the solution something to do with starting the timeline at 2 min. so the rounding of framerate was set deep into the timeline? I'm streatching here, but something about this sounds familiar.

Craig H.
cobalt wrote on 5/3/2003, 10:48 PM
I do not have this problem digitizing with the Canopus Codec and editing in the Vegas Timeline.
JohnnyRoy wrote on 5/4/2003, 12:11 AM
I can reproduce the problem with Cool 3D. I set the frame rate in Cool 3D to 29.97 and made a clip 600 frames in length. Frame 88 and 89 are identical when played back in Vegas 4, Vegas Video 3 and Video Factory 2. They are not identical in VirtualDub nor in Pinnacle Studio 8. (these were all the NLE’s I own). This doesn’t happen on captured video or video rendered from Vegas. Very strange. I never noticed this before.

Brazilian wrote on 5/4/2003, 1:20 AM
I wrote a small app to peek at the AVI video stream and show the frame rate data.

An AVI exported from a DPS Reality has it marked as straight 29.97 (2997/100), as does the AVIs After Effects makes (as we already know).

An export from an AVID DS shows 30000/1001, the more accurate version that Vegas seems to prefer.

So what other apps export seems to be a mix. The ideal solution is if Adobe used the more technically correct framerate; The 'play nice' solution would be if Vegas had a preference or some other mechanism to fudge and interpret files marked as 2997/1000 as 30000/1001 instead.

In the mean time, I'm going to slap together a small app to just change the framerate of AVIs so anyone needing to use AFX animations and whatnot can without them skipping. I'll post back with a URL.
John_Cline wrote on 5/4/2003, 2:50 AM
While Vegas may be doing frame rate "by the book", (ie. 29.97002997) it is also incompatible with all those other apps that are doing it "wrong." I almost always incorporate footage processed with After Effects and/or Virtual Dub into my productions and I'm not about to stop using them because Vegas is incompatible with their files. I'll stop using Vegas long before I'll stop using After Effects and Virtual Dub.

It's up to Vegas to deal with all the "wrong" files generated by these indespensible and popular apps. I guess it's back to Premiere for me until something gets figured out.

Hopefully Brazilian's frame rate changer will fix some of these "non-standard" files, but changing the frame rate in the header will most likely cause some audio drift issues on lengthy video files.

Brazilian wrote on 5/4/2003, 3:22 AM
Assuming the files were captured at the correct NTSC rate to begin with, the audio should be fine - the 2997/100 vs 30000/1001 rates the files are tagged with are almost just cosmetic differences in this case.

I put up a beta app call SpeedMangler which you can use at your own risk; See the enclosed readme file.
Brazilian wrote on 5/4/2003, 3:55 AM
Oops; A few minutes after I posted my message I realized that I zipped the wrong executable, and judging by my webserver logs it looks like 1 person already downloaded it.

If you grabbed the file prior to the time this message is dated, you might want to re-grab it. It was an older test build that might not properly set the frame rate if you specified it manually, like to change a file back to 2997/100 -- but shouldn't otherwise do anything catestrophic.

Sorry about that.
Tyler.Durden wrote on 5/4/2003, 7:24 AM
Hi all,

Here is one previous thread that has more info and perhaps a simple workaround:


mikkie wrote on 5/4/2003, 7:52 AM
If it helps, there are a few apps at , along with links to websites etc. that do a bit looking at avi files/streams, as well as a few that change header info. Not to shortchange Brazilian -> thanks much for the applet.

FWIW, have long had minor stuff happen from avi files that treated specs slightly differently. One thing that has helped from time to time, assuming the needed disc space is available, is to do what V/Dub refers to as a direct stream copy, in V/Dub, prem, Vegas etc... Doesn't take terribly long, and the new header info written often fixes whatever minor glitch I was experienceing.

Moving whatever types of files around from app to app, find that from time to time the spec police have let one slide by ;?o and figure I can either come up with something that works, or grow older, faster worrying about it. I mean, in the time it took to write this, I could have deleted the 89th frame in at least a few projects/files.

BillyBoy wrote on 5/4/2003, 9:24 AM
"While Vegas may be doing frame rate "by the book", (ie. 29.97002997) it is also incompatible with all those other apps that are doing it "wrong." I almost always incorporate footage processed with After Effects and/or Virtual Dub into my productions and I'm not about to stop using them because Vegas is incompatible with their files. I'll stop using Vegas long before I'll stop using After Effects and Virtual Dub."

Geez John... reminds me of the little boy who said I'm going to hold my breath until I turn blue unless I get what I want. I can see your point if everyone else had it right and Vegas did it wrong, but honestly you expect the one application that does it right to change to support others that do it incorrectly because if they don't it will inconvenience you?

Also reminds of an old StarTrek where most of the people on one planet were black on one half of their body and white on the other half. A few were born the other way. The first group being in the majority detested the other group, hunted them down, were at war with them constantly, etc.. To outsiders, BOTH groups looked alike, the only difference was one group was white on one side of their body, black on the other and the other group was reverse. The point was both groups were equally white and black, yet each group thought is was terrible to be black on the side of their body they weren't. Ridiculous reason to hate.
John_Cline wrote on 5/4/2003, 12:31 PM
Yes, BillyBoy, I do expect Vegas to make modifications to handle programs that aren't doing it correctly. Particularly when one of those programs is After Effects, which has a MUCH larger installed base than Vegas.

I'm not making DVDs of home movies for Grandma to see, my clients include one of the three major TV networks here in the U.S. and I absolutely guarantee that they would see a one frame glitch.

Also, your last message added nothing constructive to this discussion. The Star Trek analogy made no sense whatsoever. Your message also verged on a personal attack. I have read your posts elsewhere on the forum and it is my opinion that you are nothing but a whining troublemaker. Just because you can live with this issue doesn't mean the rest of us can. Kindly go cause trouble in some other thread while we get this sorted out. I'm going to go try Brazilian's app. Thanks, Brazilian!