Capturing with Virtual Dub: Corrupted sound

[SupaCoopa]

Hi all.
I have this problem and can't do anything about it. Maybe someone can help me out? Well, first you'll have to understand what I mean below...

When I capture with Virtual Dub the sound is strangely corrupted. When someone talks I can hear a brief cracking sound just before I hear their words. Then the sound is normal until there is a pause and the other person starts to talk and then I hear again this cracking sound and so on. This is really strange, as I can't hear this cracking sound while listening to real-time line-in, it's only produced on the captured recording. Also if I record line-in using Sound Recorder or whatever, there is no such corruption.

I'm capturing 480x288 with no lost frames, the sound I grab is PCM 44khz, 16 bit, mono. I check "lock video stream to audio" and "dynamically adjust video clock" as I get de-synch if I don't.
I have a Celeron 900, 512K Ram, NVidia MX 400 VIVO and SB Live and run Windows XP Pro and VDub 1.4.5 and 1.4.8.

What is wrong? What can I do about it?
Cheers

[Cart]

First of all, make sure that line-in and only line-in is selected as the recording source in both Windows' mixer and your SB mixer. Also make sure that your recording properties are set to "best quality" in the Sounds & Multimedia control panel.

Try capturing with 48 KHz to see if it helps any.

-Cart
http://www.geocities.com/lukesvideo/index.html

[SupaCoopa]

Cart, ta for your reply. Yes, only line-in is selected as recording input, and everything else is muted at playback properties.

I have tried every available sound format, from 11khz, 4 bit, mono to 48khz, 16 bit, stereo but the results are identical.
I have done some testing with other capturing programs like AVI_IO and freeVCR. Same thing happens. If I record line-in from a non-video-capture program (WinRec, Cool Edit etc) the sound is perfect!

I have been listening more careful to the "corrupted" recordings through my hi-fi speakers. It seems that the recording is actually vibrating, both in tone and volume (couldn't make that out using lame PC speakers). Maybe a case of VFW messing with timing then?

I haven't installed Creative's XP drivers, so no SB Mixer. I'm just going with XP's native SB Live Drivers, will update them to see if it makes any difference.

Cheers

[SupaCoopa]

Problem solved!

I had a look in BIOS settings and found out that AGP WS Read and AGP WS Write were disabled. I enabled both of them and now the sound of captured video is loud and clear.

Just thought you might wanted to know!