Frame Drop Problem

[Nealhon]

Hi all, I've been capturing video in VirtualDub at 720x480 (using mjpeg) with an average of about 15 dropped frames per 30 minutes... which I don't think is bad because it isn't noticable. Well here for the past few days (with no settings changed or no new progs or anything installed) it has been dropping about 150 frames per 30 minutes and there are a few extremely noticable jumps (some last a couple seconds each) and it's quite annoying. I've been reading on here about dropped frames problems and I am now defragging the PC. Does anyone have any idea why it the amount of dropped frames change so drastically? I've done an ALT + CTRL + DEL and got rid of anything that could be slowing it down (which there is nothing different there than there was before when it was dropping about 15 frames per 30 minutes) but it's still no good. I know ya'll are probably going to tell me I need to supply you guys with more info... so just let me know what to post... here's some info:

Capture Card: ATI AIW 9600
Autio Card: Sound Blaster Live! 24-bit
HD: Western Digital 80 GB 7,200 RPM
Processor: AMD Athlon XP (2700)
Ram: 512 MB DDR
CPU usage during cap: stays at about 25%

Oh and also... I used to capture the audio (PCM) at 44.100 kHz but it would drop about 150 frames per 30 minutes (and it would always drop at least 2 frames per minute) so then I tested it at 48.000 kHz and it never dropped a frame during one minute caps and it only dropped about 15 frames per 30 minutes... but now even with it at 48.000 kHz, it's back to its old self dropping about 150 per 30 minutes.

If anybody knows what might be a problem or have any suggestions for me, I'd appreciate it.

TIA!

[FlimsyFeet]

You don't say what it is you're capturing. If it's a poor quality VHS tape, then that can cause lots of frame drops.

[Nealhon]

My bad for the late reply. The source I'm using is satellite TV.

[Nealhon]

Does anybody have any ideas for me to try? :confused:

[jggimi]

There are many possibilities. Dropped frames can certainly be caused by software settings related to sound/video sync. One easy way to tell if sound is the problem is to disable sound capture in the software. If dropped frames stop happening, then you know what the problem is.

I don't have experience with ATI's VIVO cards -- do you get the problem when using ATI software rather than Vdub?

I assume you've already been thru Q20-22 in the FAQ.

[SallyDog]

What setting mjpeg are you using (18, 19, 20 ??)

What version of vdub?