ATI 600 USB capture has random garbled audio?

[jimmyz80]

So far I've been having really good luck capturing VHS using my AG-1980 and my ATI USB 600 capture device. On my most recent tape though, something really wacky is happening with the audio. Certain sections of the tape get captured with jumpy, garbled audio, and the rest of the tape gets captured fine. If I enable audio playback on Virtualdub, the preview audio I hear is crystal clear. Yet having Virtualdub capture those same sections of tape, results in garbled audio. Virtualdub is set to compress video with HuffYUV and to capture audio uncompressed.

Has anyone seen this sort of behavior, or would you have any suggestions on WTF might be going on? Attached is a sample for you to get a chuckle out of...

[lordsmurf]

I have no idea. So, unfortunately, you'll have to start troubleshooting at random.

My first (possibly lousy) idea: Make sure the framerates for capturing are correct. In theory, if the video was 60fps capture, but players at 30fps, then the audio would slow down by half. That's not usually how this would work, with a 60s fps VHS capture simply dropping half the frames, but in theory it could.

If the preview works, then the hardware is probably fine. It's something in the setup causing this.

If this is a ATI 600 USB, and you're NTSC, try a test capture with ATI CMC.

[msgohan]

Capture -> Timing is likely set to "Sync audio to video by resampling the audio to a faster or slower rate". When video frames fail to make it to the PC for whatever reason, the audio will be altered.

Since you have the ATI 600, set it to Do Not Resync.

[jimmyz80]

Quote:

Originally Posted by msgohan

Capture -> Timing is likely set to "Sync audio to video by resampling the audio to a faster or slower rate". When video frames fail to make it to the PC for whatever reason, the audio will be altered.

Since you have the ATI 600, set it to Do Not Resync.

I've always had that option turned off, since having it turned on always resulted in audio being out of sync with the video.

[msgohan]

You're also already capturing the audio uncompressed, so that's not it.

The only other thing I can think of is to always capture with audio playback disabled.

[jimmyz80]

Quote:

Originally Posted by msgohan

You're also already capturing the audio uncompressed, so that's not it.

The only other thing I can think of is to always capture with audio playback disabled.

Unfortunately that's always been the case as well (learned that lesson early on lol).

I'm wondering if this is actually some sort of tracking or dirty head issue with the deck, that only appears sporadically. I've tried capturing this tape a few times and it's always the same sections of the tape that get garbled, and it's most of the time, not all the time. I have a wet cleaning tape I'm going to try out and see if that changes things at all.

[lordsmurf]

Never use cleaning tapes. Those just push dirt and, or even worse, damage a VCR.
Take the deck apart, and use some NON-COTTON swabs to clean it.

Refer to: http://www.digitalfaq.com/forum/vide...html#post21870

We use DSLR swabs made for clean cameras. Chamois and foam also work.