Gradual Loss of Sync in new Capture

[AlienTiger]

I have a gradual loss of sound/video sync in a 2 hour capture, it starts around 400ms and by the end of the movie is around 5-600ms offsync, first off ive never had this issue with any of my past captures, i use an AverMedia 1500 MCE card, I capped the program at 5000kb/s MPEG2

What would cause this and how do I fix it?
thanks for any help

[AlienTiger]

:(, i thought i would have had an answer to this by now anyone at all have a slight clue on this?

[jggimi]

...ive never had this issue with any of my past captures...

But obviously, something is different, now. Perhaps new background task(s)? New hardware added, or current hardware drivers updated? OS patched? BIOS updated or settings changed? Adjustment to virtual memory settings in the OS?

My guess is that you are getting frame drops, since you are encoding to MPEG-2 on the fly with your CPU, and at a relatively high bitrate. Did you change GOP settings in your capture program? That can have a significant impact on CPU consumption.

Have you seen Q20 and Q21 in the Capture FAQ (http://forum.doom9.org/showthread.php?s=&threadid=32575)?

[rfmmars]

I use ATI cards with hardware assist MPEG2 Ligos encoding where you can't drop a frame or loose AV sync. If your is software encoded the above post may apply.

richard
photorecall.net

[jggimi]

Good point. I looked up his product just now, here (http://www.aver.com/products/tvtuner_UltraTV_1500_MCE.shtml). It does have a hardware MPEG-2 encoder; I'd assumed MPEG-2 in software.

If audio goes through the internal audio input on the card, then the card should not be losing sync. Time to contact AverMedia (http://www.aver.com/support/).

[AlienTiger]

:/ ive did captures since and none have that same problem, i never have anything else running, in fact I bought the system primarily for Capping/Encoding, and nither run at the same time as the other, havent changed anything at all either, so could it really be the card thats causing the trouble then, its still pretty new, bought it in January

[rfmmars]

If the clock on the sound card is not stable, this can be another problem.

richard

[Boulder]

If you can, try selecting Program stream (PS) or DVD as the MPEG2 container format. I don't know what the exact difference is, but some people have had better experiences regarding a/v sync with either PS or DVD streams.

[AlienTiger]

I dont believe i have those options, i can only save to dvd format in MPEG2 not the VOB container and ive never seen PS option :/