frame drops and signal quality

[dirk67]

I'm caturing with a WinTV-Go and VirtualDub on an Athlon 1.4 GHz system in 352x576 and observed the following: If I capture from an analog satellite tuner, no frames will be dropped (15%-30% CPU load). If I capture from VCR, I will get 0.5% dropped frames for new recordings on high quality tape and up to 30% dropped frames for older recordings on medium quality tapes. The CPU load is 30%-50%. Does anyone have an explaination for this? The visible difference between the recordings is not that high. Would a signal intensifier used for VCR to VCR copies help?

[vhelp]

dirk67,

That's strange. But then again. . .

It could just be that there's still too much bandwidth goin on there.
I've done a lot of VCR captures - from 1 min. caps to over an hour
with my DC10, and I've never had any frames drop! I've capped
from my regular VCR and from my S-VHS - no drops in frames.

The only time when I do drop frames (can be many) is when I
FF or RW during my captures. Then I drop frames, and sometimes
pretty crazy.

I think it may be due to lack of bandwitch. I'm gonna have to test
this out myself, but with the hauppage wintv pci card I've ben testing
for the last couple of days. Its a little too late right now. maybe
tomorrow - I don't know.

------------------------------------
DC10+ Samples

<font size=-1>[ This Message was edited by: vhelp on 2001-11-20 00:05:15 ]</font>

[dirk67]

vhelp,

thanks for your answer. What bandwidth do you mean? In the analog signal? Or in the captured data? The latter cannot be the case, because the data rate is always the same (about 200 kb per frame or 5 mb per second with huffyuf). It seems to depend on signal quality and/or noise in the signal. By the way, the satellite tuner where all works well is connected through the VCR, so it cannot be the cable.