Preview window is choppy in Vegas 4 (11.43fps)

JohnnyRoy wrote on 2/16/2003, 7:04 AM

I’m hoping this is just a parameter tweak somewhere. In Vegas 3 my preview playback is as smooth as silk. In the Vegas 4 beta my preview playback was as smooth as silk. Since it was about to expire, I uninstalled the beta and downloaded the demo of Vegas 4 until I can upgrade in March. When I preview the exact same video clip in Vegas 4 it plays back very choppy using Preview (Auto). Like it’s stuttering. The voice seems almost out of sync with the picture. I even changed the preview window to Draft (Auto) and its still choppy. What’s strange is that when I play the clip in Vegas 3, my hard drive light is almost steady and the video is smooth. In Vegas 4 my hard drive light is pulsating (i.e. choppy) just like the video. I tried a rolling credit and got the same choppiness. There wasn’t any hard drive activity to do that. The same credit in Vegas 3 rolls smoothly.

In the status area of the preview window on Vegas 3 it says Display: 360x240x32, 29.97 when playing a clip. In Vegas 4 status area is says Display: 360x240x32, 11.43. Why can’t Vegas 4 display faster than 11.43 fps with just one track with a DV AVI on it? I also noticed that when I start playback in Vegas 3 the status immediately says 29.97 and stays there, but when I start playback in Vegas 4 the status flashed 29.97 for a brief second, and then drops down to 7.xx and slowly climbs up to 11.43fps after about 5 seconds. It never gets faster that 11.43fps from Draft (Auto) right up to Best (Full). Same results every time. Even if I just play back a solid color generated media. I can’t get it to play back faster than 11.43fps.

What changed from the beta to the real product that could cause this? What can I look for in the preferences to possibly change? I haven’t tried yet but I usually PTT from the timeline and this doesn’t give me a warm fuzzy that its going to work smoothly. I have a Dell 8100 P4 1.7GHz, 512MB memory, 60GB primary/30GB separate capture drive, nVidia GeForce4 Ti4200. I don’t think its my computer since Vegas 3 and the Vegas 4 beta ran smoothly. Anyone got any ideas?

~jr

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JohnnyRoy wrote on 2/18/2003, 4:14 PM

Well guys, Dennis help me find the problem on my machine. I hope it’s the same on yours so this fix will work for you.

The problem was with the audio not video. I’m using a Creative SoundBlaster Live! Platinum 5.1 card but it may affect other cards as well. What I had to do was go into Options->Preferences->Audio Device (tab) and change my Playback buffering (seconds): from .35 to .40. That was it. As soon as I did that, the clips shot up to 29.97 fps. You may have to increase it more but I tested it all the way up to 1.00 and it didn’t get any better than .40.

I did notice that the fps display flickers a bit from 29.97 to 29.63 and back for a brief second while playing but this happens even when there are no events on the timeline. In Vegas 3 it just stayed solid unless it was passing over a transition. At any rate, I’ve got my playback back up to 29.97. Hope this helps one of you.

A big public THANK YOU to SonicDennis from me. SoFo has the best customer support bar none.

~jr

lkdhiri wrote on 2/18/2003, 5:21 PM

Hi Dennis and others,

I am using a PIII-M 1GHz, 512 MB RAM, 80 GB (7200 rpm) firewire based capture hardisk and have stutters when viewing clips through the preview monitor. My frame rate doesn't drop like mentioned but Vegas 4 can not be used during the stutter. However, Windows 2000 is fine.

I have tried changing the audio buffer (various settings higher than 0.35 up to 1s), changing preview monitor quality and using zoom when playing from timeline but nothing has helped eliminate the problem.

TIA

PS the PAL DV clips total to about 30 min but the stutter starts quite early on after say adding three clips which are less than two minutes total.

Jessariah67 wrote on 2/18/2003, 5:47 PM

Jessariah67 wrote on 2/18/2003, 5:52 PM

Sorry for the double post...

I have a Delta 44. The buffering settings did not help the problem. I also tried changing the number of buffers up and down and the priority, but it still didn't help. I'm playing back in the mid-teens to low-20s fps with no plugins, etc. Again, this problem is not present in VV4 Beta or VV3...

I went in and checked the box for Microsoft DV Codec, and that takes me to the mid-high 20s, but still not a steady 29.97 fps.

SonyDennis wrote on 2/18/2003, 10:51 PM

I can't say for sure if this is what's causing any other playback stuttering or low frame rates, but I had JohnnyRoy run some additional tests that confirmed a subtle interaction between the video and audio threads that can cause the video to drop frame rate in certain cases. We're working on fixing it up for the forthcoming update.
///d@
P.S. If things went from smooth in the beta to choppy with the released version, they might be related to this, but I can't say for certain until we fix it.

pike_bishop wrote on 2/19/2003, 3:26 AM

I have a soundblaster platinum card in my machine, I'm at work at the moment but I'll give your suggestion a try when I get home Johnny.

Thanks again
Martin

pike_bishop wrote on 2/19/2003, 3:10 PM

Johnny & Dennis

Thank you both I tried your suggestion of changing the audio playback buffering and it worked. I now get 25fps (I work in PAL) and my RAM previews work aswell. Thanks
again and if either of you are ever in London UK the drinks are on me!

Cheers
Martin