[mythtv-users] Cannot get EIT and picture data on same channel

Stroller linux.luser at myrealbox.com
Thu Jan 25 13:46:27 UTC 2007

On 24 Jan 2007, at 18:54, Philip Allison wrote:

>> I'm not able to take that as a given, from your posting. I mean, if
>> you tell me that you can see Crystal Palace from your bedroom window
>> then I take it all back, but isn't it possible that poor reception
>> (or a bad tuner) would cause these symptoms?
> I don't know. I was kinda hoping that was the sort of thing this list
> could tell me. What I don't understand is how the application is  
> able to
> retrieve ONLY EIT from one multiplex, and ONLY picture/sound from  
> another,
> if that is indeed what it is doing - I would have assumed that, being
> digital, the signal would generally be good for all or nothing.

I don't know if this is a given or not. I mean, I've seen poor  
digital reception cause dropped frames and blocky mpeg artefacts.  
These are quite visible, and indicate that "some" of the signal is  
being received but not "all of it". Isn't it possible that at one  
frequency one might get a decent picture but poor reception cause the  
EPG to fail? I admit that it seems less likely that a poor signal  
would cause only EIT data to be received, but I'm really not  
qualified to say.

I read <http://www.gossamer-threads.com/lists/mythtv/users/ 
245481#245481> that with the ivtv driver it's possible to `cat /dev/ 
video0 > test.mpg` & `mplayer test.mpg`; is this possible with your  
card? I think this would allow you to view the channel 1 - is it  
jittery or blocky? - and maybe there tools that would allow you to  
try extracting the EPG data from channel 541. This would determine  
whether the problem is with MythTV or with your PCI card or its  
driver. I think you might also find the linux-dvb mailing list useful.

> Let me be more blunt, because clearly at least one person here is  
> having
> trouble seeing what I'm getting at.

I wasn't having trouble - I did understand your description of your  
symptoms. But I wasn't able to offer any better help, and seeing as  
no-one else had replied I thought that (if nothing else) my comments  
would give you a "bump".


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