WinXP, AthlonXP/KT266A mobo, firewire preview stutters

DougHamm wrote on 12/27/2001, 4:20 PM
Howdy folks. First off, a show of hands please. Who runs a rig similar to mine:

- Athlon XP (mine's an 1800+)
- Windows XP Pro
- VIA KT266A DDR mobo with all drivers applied
- VV3
- OHCI firewire card

Alright! Now, here's the problem I'm having and I'd love to know if anyone else experiences the same phenomenon.

When capturing from DV (either from my camcorder or my Sony DVMC-DA2 box), response is instantaneous and ne'er a frame is dropped. So far so good.

When playing back a finished project from the VV3 timeline, no hiccups at all. So far so good.

Incidentally, I use Scenalyzer Live to play rendered .avi's to the camcorder (it's got some advanced buffering techniques to further prevent dropouts and I used it exclusively with VV2, so old habits die hard). When doing so, I notice that there's a few seconds lag between what's on camera and what's in the preview window. Never noticed this in my older, slower BX-based PIII system. However it continues to play just fine out to tape, so no big deal.

Now here's the real annoyance: when _previewing_ in VV3 out to firewire, I notice the following:
1) When I press Space to start/stop playback, the firewire preview jumps a few frames every so often. It's stuttery. If I quickly zoom in and out while this happens it's worse, or if I zoom up close enough that the timeline is constantly redrawing it's also worse. Stopping the playback and restarting it can clear up the stutter, for a bit. No grey blocks or blue screens...just herky-jerky playback.
2) When clicking from the trimmer back to the timeline and vise-versa, VV3 seems to 'lose' the firewire and it takes a few seconds to reinitialize the preview. Never noticed this before but I made the switch from a PIII/Win2k/VV2 system to the Athlon/XP/VV3 simultaneously. So I'm not sure where the problem is!

That's really it. If I just work within the on-screen video window there's never a lost frame or stuttery moment. Only previewing through firewire stutters.

Final playback, again, is also perfect. So does anyone else with a similar system experience this?

I thought it was perhaps a bandwidth-sucking AGP card taking cycles away from the firewire card (nVidia cards are notorious for high PCI latency settings and aggressive bus usage) so I put in a Radeon 8500 instead. No difference. Tried multiple slots and IRQs, a different firewire card (still TI-based), and still no difference. What DID seem to make a difference was forcing the old native TI drivers to be installed in place of Microsoft's OHCI camcorder drivers. There was no stuttering at all while previewing - for the few seconds at a time it would work before VV crashed and burned with big error messages. :)

Is this an XP-ism that I have to live with until DirectX 8.2 comes out, a VV3/XP incompatibility, or perhaps some VIA chipset problem? No big deal, really, since it's only on preview that it happens - but I figured that by quadrupling my CPU speed the last thing I'd see would be frame stutters... :)

BTW, audio never stutters - only video. Perhaps XP doesn't like VV3's method of sending video out firewire while sending audio out the sound card when previewing...

Thanks guys,

-Doug

Comments

Rednroll wrote on 12/27/2001, 4:25 PM
Sorry, reading your post became too painful about halfway through, where I almost nodded off and passed out on my keyboard. Can I have the Krib notes version of your question?
DougHamm wrote on 12/27/2001, 6:38 PM
Hah!

Sorry, I've been putting two weeks worth of thought into this and wandered a bit. :)

Long (long) story short - anyone using XP on an Athlon notice stuttery preview out firewire during editing? Capture and print-to-tape works fine.

Thanks!

(Better?)
Rednroll wrote on 12/31/2001, 11:02 AM
I've heard of some people having this problem and changing the monitor out, to a higher quality actually fixes this sometimes. In other words, I've heard where it would studder in "Preview" quality and would not studder in "High" quality. Try the different settings for quality output for previews and see if that helps.
DougHamm wrote on 12/31/2001, 11:38 AM
Thanks for the suggestion - I'll give that a shot. I've discovered that a good defrag helped quite a bit, as did unplugging some USB devices. I was wondering why my CPU would spike to 25% every few seconds like a heartbeat; by unplugging my scanner this dropped to 0-1%. But I'll play with the preview settings as well and see if I can eliminate the stuttering even more.

Take care,

-Doug
wvg wrote on 12/31/2001, 8:38 PM
Stuttering in the preview window is generally caused by having a slow CPU, low system resources, too many other applications running and other user controlable things. I use two main machines. Trying to preview on mu aging PII 400, it crawls, jumps and sputters. Rendering same video on my AMD 1200 flys along almost in real time even at best quality.

If you get stutter in the rendered file (I do sometimes) that's another story and as yet I haven't seen it addressed by VF folks in the forum.
Kjtwist wrote on 1/12/2002, 1:30 AM
I though it was only me. I have a MSI KT7266A with 1 and 1/2 gig of DDR Ram, XP PRo and new MAxtor ATA 133 HD. I don't get real time output to NTSC monitor. Also noticed sound doesn't go thru the firewire, have to run a patch from my sound card. If I could eliminate this jerky motion on unrendered transitions I would be in real real time business out to analog. I have tried everything you have, still the same problem.
dvstudio wrote on 1/12/2002, 2:21 AM
Is this MSI the K7T266 Pro2? I've built 5 of these with no problems(just finished #5 a couple of hours ago) but I'm using Win2000, havn't tried XP. I'm also using the Matrox G450 cards which are best for 2D and video.

Try changing your AGP aperture from 64MB to 256MB in the BIOS. ???
Kjtwist wrote on 1/13/2002, 5:56 AM
I posted the same question over on Creative Cow Heres the thread if your interested. http://www.creativecow.net/cgi-bin/read_post.cgi?forum=sonicfoundry_vegas&postid=3033

It seems like their saying you will not get perfect real time preview before rendering of transitions and effects. When I preview out to my NTSC monitor my frame rate drops when it displays transitions etc.. No getting around this it seems, prove me wrong please. The real time previews we do get though are very good. Better than any other software only solution Iv'e seen.
DougHamm wrote on 1/15/2002, 4:35 PM
Hmmm...never was able to get rid of the stuttering effect completely when previewing out to DV. It could be a bunch of different things but the only thing I haven't tried is downgrading back to Win2k. I have a sneaking suspicion that would fix it...too bad XP Pro has some nice features I would miss.

The only time it didn't stutter when previewing was when I managed to install the old TI driver (dvcam.sys) in place of XP's DV driver. Of course it crashed within several seconds of testing but during those several seconds, not one hiccup out the firewire port.

-Doug

-Doug