[mythtv-users] Advice on buying DVB-C card with CI support

Mark Wormgoor mark at wormgoor.com
Fri May 15 11:26:02 UTC 2009


Hi,

> I am looking at buying an software decoding PCI based DVB-C card for 
> running with mythtv, and then I mean something that has "working" 
> CI-support under linux. I have been looking a lot at 
> http://www.linuxtv.org/wiki/index.php/DVB-C_PCI_Cards to try to figure 
> out what to buy, but there always seems to be an issue with either the 
> CI-support or running under mythtv.
> 
> So is there anyone running with an DVB-C card and  working CI that knows 
> from experience that it's working more or less flawlessly under mythtv 
> 0.21+?
> 
> My best options seems to be the KNC1 TV-Station or the Satelco 
> EasyWatch, but does anyone have experience with running these with an 
> betacrypt 2 cam and  HDTV channels?

I have the KNC1 (older version with TDA10021). I'm running this without 
a CI (Softcam instead). The theory is that it's fully supported, but I 
still have issues every now and then. Some of my recordings tend to skip 
a second every couple of minutes, but some work find. I had to increase 
the DMA buffer to get it to do somewhat watchable recordings at all 
(options budget_core bufsize=1410). And every now and then, I get an 
error in /var/log/messages:
saa7146_i2c_writeout [irq]: timed out waiting for end of xfer
I've increased the PCI latency to 64 already, which seems to have helped 
a bit as well.

I'm not sure what the deal with this card is, or why it's bugging me. It 
could be my setup, but I can't get it 100% stable. I think it's due to 
the SAA7146 chipset. Love the comment on the wiki 
(http://www.linuxtv.org/wiki/index.php/Philips_SAA7146): "This hackish 
approach works surprisingly well in most setups, and only a few have 
problems with high data loss."

On the bright side, I have ensured I have a decent cable connection (BER 
between 00000000 and 0000000a) and the sound and picture are absolutely 
perfect when it does record!

Kind regards,

Mark




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