Odd playback stuttering

[InfoCynic]

Alright, I've tried everything I can think of, and I still get weird stuttering during playback of ANY xvid file, no matter the bitrate, audio used, container, player, etc. It looks like just what you'd expect if the CPU couldn't keep up or something, where the video will freeze for a few seconds while the audio keeps going, then the video will run quickly to catch up. This happens about 2-3 times during a typical 45-minute video.

I have tried: updating video drivers, updating mainboard and audio drivers, changing players (tried Zoom and MPC), various FFDshows (currently using 20051129), etc.

The problem happens in all of the files I've tried, including normal Xvid + MP3 in AVI, high-bitrate Xvid + AC3 in AVI, high-bitrate
XviD + AAC in MKV. It does not seem to happen more or less frequently in any of these files.

System specs:
ATI Radeon 8500 (using SVideo out to TV)
nForce2 Chipset (MSI mainboard): onboard audio (using S/PDIF)
Athlon XP 2500+ (currently not overclocked)
768 MB RAM
WinXP Pro SP2

The system used to play fine, but a few weeks ago I reformatted because I was having other issues. Since then, it's never been quite right.

If you have any suggestions, I'd be really interested. I used to be the expert at this sort of thing, but these days, I haven't been keeping up, and I can't think of what else to try.

[InfoCynic]

Well, it's been a while and I've made no progress, thought maybe I'd bump this with a few notes about what I've tried:

Wound up re-reformatting, so I have another clean installation. Was very careful to install drivers and reboot after each. Installed all windows updates but no audio/video drivers from there. Have tried closing all other applications while playing, but it makes no difference. Have gone into BIOS and turned off Video BIOS cacheable, AGP 8x support, etc., basically anything that looked like it had to do with the video subsystem.

I tried using CCCP, which is basically Haali's splitter plus FFDShow, then uninstalled that and installed Haali's and FFDshow manually, didn't make any difference.

The skips happen randomly per file (different places) and some are worse (longer) than others... sometimes it will just be a quick stutter and sometimes it will take 5-10 seconds to fully recover.

I am totally at a loss here, and it's driving me crazy. ANYTHING you guys could suggest would be great.

[chros]

Have you check the CPU usage during playback and without playback?
What about the other media files? eg. H.264+AAC on mov ?
Have you virus-scanned you pc ?

[InfoCynic]

CPU usage while nothing is playing 0-5%. While playing is hard... but I just started an mkv playing on the extended desktop to the TV, and I'm seeing CPU for zplayer.exe in the 20-40% range, overall usage seems to be 25-50% right now. About 300M of Physical Memory are currently available, but the number is falling (that could be firefox too, it's got bad memory leaks). I see one spike in the CPU graph to about 80% now, since I started typing this post, but it's still normally between 20 and 50.

I don't have an h264+aac in mov, I suppose apple's quicktime trailers would do for that.

I have virus-scanned with Symantec Corporate 10 which is also running in the background always and found nothing.

[InfoCynic]

I downloaded a few trailers (H264 + AAC in MOV) from Apple's site and played them in Zoom powered by QuickTime Alternative and FFDShow. Eventually, one of them experienced the same skipping. I finished playing it, backed up to the spot just before the skip and played, it didn't skip then, and then I stoped and restarted from the beginning and it played through fine (but at 2:30 it's not very long). So the skip continues to seem to affect every time of media and randomly.

[setarip_old]

Hi!

1) Test for bad RAM

2) Check to see if your system is overheating

[InfoCynic]

Heh. I just ran memtest overnight, 8 hours and no errors, 10 passes. Overheating occurred to me too... I've got Motherboard Monitor running now... at idle, CPU is 46 C. After playing the XMen 3 trailer on loop for about 10 minutes, the CPU is 48 C. Don't have longer to test right now, but I don't think it would get much hotter than 50 C, 55C on the outside, and that's not so hot as to cause problems, last I knew.

[Nudnik]

It sounds as though your hard drive might be failing. Try running a diagnostic program tailored for your drive.

How old is the PSU, and who is the manufacturer?

What were the "other issues" you were experiencing?