[mythtv-users] tuning two-card systems ?

Adam Felson a.f.5 at pobox.com
Tue Oct 19 14:36:03 UTC 2004


>I just managed to build my two-card (bttv cards!) system.  It works
>fine I guess, when recording two channels it is 0% idle, but still
>everything appears to get to disk just fine for now.  I've seen no
>jerking or hiccups or artifacts.  More on that setup below. First my
You're still misreading your cpu useage.  There's *absolutely* no way
you're running two cards with no cpu useage.  Impossible.  Absolutely.
When I ran two cards on an Athlon XP 3000, I typically got 30% useage
for the card processes alone and another 25% per transcode process.  If
I did mpeg4 encoding in real time, I got 30%/card.
Nowadays I'm running two pvr-250s an one bttv (bt878) card.

>I notice that my two bttv cards are not what you'd call exactly in
>sync, where the tuners are concerned.  If one card gives good picture,
>the other is just slightly off-channel so the colors are too
>pronounced, or I get stripes and other interference.  Now what I wonder
>is this, can one finetune channels per-card, or is the channel
>frequency globally defined for all cards ?

I've never had color problems.  Perhaps you have a defective card or are
running an old version of video4linux.

You shouldn't need per/card finetuning as they're receiving the same
signal.  Spend the $35 and replace the defective card.

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