Why is Vegas preview jumpy?????

[Bill Grant]

Hey All (especially Ed Troxel)
I have problem in Vegas 6.0 of my Preview being extremely jumpy and slo when I add any kind of effects or slow motion, really anything but the clip as normal. I have recently upgraded my video card to help with this, but it has not gotten better. I have 2 gigs if DDR2 ram, p4 3.2, and a new nvidia 7600. This thing should smoke a preview. I have tried draft, preview, and best settings, and it doesn't change. I don't have any other programs running when I edit, and the system generally runs very well otherwise. Is there a setting in Vegas that can help with this preview issue? It is affecting my ability to time cuts to the music. Thanks in advance.
Bill
Grant Photo & Video

http://www.grantphotovideo.com (http://www.grantphotovideo.com/)

[kirklandvideo]

Vegas doesn't use the video card for anything so it shouldn't matter what sort of card you have. Maybe the hard drive isn't delivering the goods?

Even on my dual core systems Vegas gets choppy if you add some effects although slow motion is generally ok. How many frames per second are you getting and what effects are you applying?

[RatVega]

Vegas doesn't use the video card for anything so it shouldn't matter what sort of card you have. Maybe the hard drive isn't delivering the goods?

Even on my dual core systems Vegas gets choppy if you add some effects although slow motion is generally ok. How many frames per second are you getting and what effects are you applying?

I held off because I don't use Vegas and therefore don't have a full understanding what all goes on there, but the "blessing and curse" of NLEs that do not rely on specialized hardware is that they are scaleable and quickly adaptable to change. This manifests itself in superior playback performance on computers with really fast processors and good functionality on slower systems. The latest version usually performs best on the latest hardware...

The issue of how much performance enhancement can be seen by upgrading the video board is going to be dictated by how aware the application and the operating system are of the asset. Early MacOS X systems don't see the same level of overall performance improvement from a fast video board that later versions see. I expect that the same is true in PCs.

The other good news/bad news scenario is that, pretty much across the board, a single 32-bit processor doesn't qualify as "fast" anymore... Heck, even dual 64-bit processors are becoming ho-hum with the latest advances. In the same light, the disk and video board assets frequently need to be improved in order to maintain system balance.

I can't say with any confidence what the most probable bottleneck is in a PC running Vegas (maybe Edward can), but the CPU and disk speeds are the most probable in the general sense.

[Bill Grant]

Well, I finally had the time to follow the other good suggestion that I got, which was to take the HD I have SATA WD320 out if the USB 2.0 enclosure and attach it to the MB. I did this and found no change in the jumpiness. I did notice in the of the preview window it wells me that I'm running 4-6 frames per second... Any other suggrstions?
Bill

[JC/DV]

That's odd Bill. This might sound stupid, but do you have anything running your CPU to death? CTRL ALT DEL and sort by CPU... anything other than Vegas running much might be causing that to happen.

[kirklandvideo]

I really can't think of any reason for it previewing slowly on that system other than the effects themselves. hardware wise, it shouldn't even be raising a sweat.

Processor intensive stuff like gaussian blur, the glow filter, etc can cause that sort of drop in performance. Also transparency and some compositing modes.

Just clutching at straws really... want to post the .veg file? Might be able to spot the reason, or at least test it on a different machine to compare performance.

Also is this SD or HD?

[JC/DV]

Hey Jeff, I was just thinking the same thing and was going to post that regarding posting the veg file.

Bill, might also try a new veg file of a simple A:B cut and see if it happens with the same media on the same drive. If it doesn't then there is something messed up with settings on that particular veg project. Sometimes getting happy with keystrokes can change something and mess it all up (happened to me once long ago, but cant remember what it was.

[Bill Grant]

Hey thanks for the responses guys. The same thing happens on every project. The main thing that causes teh jumpiness is the glow filter, or light rays. Slow motion is hit or miss, and things like Black & White and film grain stuff is better but not great. Let me pose the question this way. Is there a way to put a "soft filter" kind of thing on the clip without glow?
Thanks
Bill
PS I can post the veg file, I'll have to switch computers. and BTW it is SD

[JC/DV]

Post it and let us see it...

[Bill Grant]

ok ummm here we go... it won't let me attach it so here...

http://www.grantphotovideo.com/opening.veg

[JC/DV]

I can't see anything wrong with the veg file.

[kirklandvideo]

put a "soft filter" kind of thing on the clip without glow?
I find the glow filter causes way too much of a CPU hit and I'd expect that's the cause of the problem. I'll play with your .veg file anyway and see.

For soft focus, I usually add a marker as a note and leave the effect until the last minute. The least CPU intensive way I've found is to duplicate the clip on a new track above the original and apply a gausian blur to it, set the track compositing mode to screen, softlight or something similar, and then use clip transparency to blend the two together.

Even then, it pays to pre-render that section so you get normal playback...

[Bill Grant]

Thanks Jeff,
I certainly understood all of the english words you said there, just not how they fit together. I have never been trained formally on the basics of Vegas or editing or that matter. I guess things like compositing, and prerendering are the graduate level Vegas stuff. So, what I think you are saying is that realtime effects like glow, and light rays are hard for Vegas to pull off. It is not that I have something set wrong?
Bill

[kirklandvideo]

I did a couple of tests - on my Athlon dual core 3800 (2.1ghz) machine adding the glow effect drops the playback frame rate down to about 6fps.

[RatVega]

Thanks Jeff,
I certainly understood all of the english words you said there, just not how they fit together. I have never been trained formally on the basics of Vegas or editing or that matter. I guess things like compositing, and prerendering are the graduate level Vegas stuff. So, what I think you are saying is that realtime effects like glow, and light rays are hard for Vegas to pull off. It is not that I have something set wrong?
Bill
Bill,
I think what Jeff is saying is that a Glow filter demands a great deal more processor power than you might have imagined. This isn't a flaw, it's the nature of the filter (if it's a good one, which I suspect it is.)

A "glow" or "diffusion" filter would be analogous to a "feather" instruction in Pshop except that it works on the Luma (brilliance component) of the frame and "feathers" everything based on its brilliance. Increasing the brilliance overall is trivial, but when you you ask for a relative (and non-linear) shift based on the luma map a huge amount of math is required because the luma varies continuously to start with.

I was adding some advanced diffusion effects to a couple of clips last night that only had fundamental color correction on them and they would no longer playback at full quality/full frame rate on my tweaked out (dual 64-bit) G5 which will kick out 36 billion floating point operations (GigaFLOPS) per second... This is exactly the thing that got Magic Bullet a bad rep as a "render hog" (though both systems and software have improved lately.)

[Edward]

You can find some interesting timings in this thread:
Sony Media Software - Forums - Vegas - Video Messages (http://www.sonymediasoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=401776)

Glow is a roughly 9:1 hit. Several like Mask Generator, Levels, Black Restore are all in the 1:1 range so are very easy on the CPU. Some that are even worse than glow are Light Rays, Deform, and the absolute worse is Min & Max at roughly 172:1.