[mythtv-users] Cannot change channels with M179

Joseph A. Caputo jcaputo1 at comcast.net
Wed Jul 20 13:39:45 EDT 2005

On Wednesday 20 July 2005 0:45, Scott Alfter wrote:
> Are you running into any signal-quality issues, by any chance?  I got 
> one of 
> my M179s running again (this time alongside a PVR-350 and a 
> PVR-250MCE).  
> I'm using the same ivtv version as you, with the kernel (2.6.9) 
> tuner.ko 
> used instead of the one provided with ivtv.  Passing the tuner types 
> (8 for 
> the PVR-250MCE, 2 for the PVR-350 and M179) to ivtv got the tuners on 
> all 
> three cards working.
> However, the signal quality on the M179 is still far inferior to the 
> two 
> Hauppauge cards.  The tuner input picks up more RF noise that shows up 
> as 
> various kinds of interference patterns (odd, since the PVR-350 uses 
> the 
> exact same tuner).  I then figured I'd go ahead and use the Hauppauge 
> cards 
> to tune analog cable and plug the digital-cable box into the M179.  
> While 
> the picture quality on the S-video input is good enough, the audio has 
> an 
> unacceptable amount of crackling noise in the background.
> Is there anything I can do to get the M179 working better on either 
> the 
> tuner or S-video input, or should I rip it back out and forget about 
> ever 
> getting it working properly with MythTV?
> (I've done some composite video capture with the M179 on a WinXP box, 
> and 
> the audio didn't make the crackling noise it does under Linux.  Is 
> ivtv not 
> initializing something on the card properly?)

I don't have  any other cards to compare to, and my TV-out is so crappy 
it's hard to figure out whether any picture problems are introduced by 
the M-179 or the TV-out encoder.  I will say that the quality degrades 
quickly if there's any noise in the incoming signal.  As soon as I have 
some spare time and spare cash I'm going to try out ain Air2PC or 
pcHDTV card, plus get a TV with digital inputs so I can take the TV 
encoder chip out of the equation.


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