[mythtv] Problems with channel scanning (DVB-C, PAL, Finland)

Ilja Jetsu ilja.jetsu at gmail.com
Wed Sep 20 06:42:04 UTC 2006

Actually I must now again reply to myself, since I noticed that there
is one message that I sent that got stuck inside some moderation
engine of this list :) (Didn't send it from the correct address)

On 18.9.2006 Ilja wrote: (talking about the problems with EIT)

This might be actually trying to fix the wrong problem (the channel
scan doesn't work, I have heard from at least 2 different cases in.
All in finland and on DVB-C), but if I get the EIT work my wife wont
have a problem -> I dont have problem :)

Janne Grunau wrote:

> On Monday 18 September 2006 08:55, Ilja Jetsu wrote:
>> Answering to myself :)
>> Unfortunately no complete solution has been found yet.
>> (I think that I'll have to compile the program with debug mode on.)
> No, it's not neccessary. You have to look what (if any) data is broadcasted. dvbsnoop -nph -n 10 0x12 while tuned to each multiplex should clarify if EIT data is transmitted.

Ok, that's great. It worked well, see bottom for examples.

>> But.. something has happened to this, because I can't get any EIT
>> information for other than the programs in the second multiplex. (YLE
>> programs) Even though it scans from all mplex:es.
>> It doesn't seem to be a myhtv-specific problem, because tv_grab_dvb
>> doesn't find any EIT info for those other channels either.
> I would think that your cable provider doesn't transmit any guide data (according to the DVB specs he should at least transmit now/next data).

Actually they do. I didn't remember wether I should attach the files
to this message, but now here is links for different results:

dvbsnoop from multiplex that works (nwid:15 tpid:3)

dvbsnoop from multiplex that does not work (oddly it seems to
transport as much info as the other)

Result of making a full scan of the network:
(starting with values      162000000,6900000,auto,qam_128)

(should be about)
MHz     Mod    Symb
426    QAM128     6900
418     QAM128     6900     MTV3,Nelonen (not working)
162     QAM128     6900     YLE (working)
154     QAM128     6900
410     QAM128     6900
434     QAM128     6900
450     QAM128     6900
458     QAM128     6900
466     QAM128     6900
170     QAM128     6900
402     QAM128     6900

Channels found only from the YLE-multiplex (162MHz)
Other multiplexes give errors about not being correct

If somebody can give some other ideas what to try, it would be great.
I'll try to fix the values created by scan by hand, let's see if that helps.

WAF of MythTV is getting lower in this household minute by minute.. :)


--End of the original message --

I actually did some extra screencaptures, to give better idea what I
am doing. (English is not my native tongue, so  te pictures might tell
more than thosand words.. ot something)

Beginning state, no multiplexes set, doing scan

Scan complete, channels from that multiplex found no errors

List of other multiplexes found (that one frequency is a bit odd :)

Well, i want more channels so let's do a scan for all multiplexes

Whoops some errors occured

Same errors on a background commandline

List of multiplexes after doing the full scan

I'm willing to help investigate this problem further. I actually
managed to build the svn trunk in a debug mode, but haven't installed
it yet (must do some work, will continue on the subject at evening :)


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