[mythtv-users] DVB-T Hell in Sydney

Stephen Worthington stephen_agent at jsw.gen.nz
Mon Jun 6 04:37:57 UTC 2016


On Mon, 6 Jun 2016 01:18:15 +0000, you wrote:

>Hi,
>
>On 4/06/2016, 10:00 PM, "mythtv-users on behalf of
>mythtv-users-request at mythtv.org" <mythtv-users-bounces at mythtv.org on
>behalf of mythtv-users-request at mythtv.org> wrote:
>
>>I've found w-scan to be very good & fast.
>>https://linuxtv.org/wiki/index.php/W_scan
>>http://wirbel.htpc-forum.de/w_scan/index_en.html
>>
>>Mythtv-setup scan with verbose logging (of scanning/tuning) is very
>>impressive & informative.
>>
>>"Femon" is handy for checking cables/connections etc..
>>
>
>	I agree, mythtv-setup's scanning is impressive and seems to leave my old
>trusted tools in the dust.
>
>	I hadn't heard of w_scan so I tried it out:
>
>root at spug:~# w_scan -v -c AU -X -C UTF-8
>using settings for AUSTRALIA
>DVB aerial
>DVB-T AU
>scan type TERRESTRIAL, channellist 3
>output format czap/tzap/szap/xine
>output charset 'UTF-8'
>Info: using DVB adapter auto detection.
>   check DiBcom 7000PC:
>           DVB-T
>        /dev/dvb/adapter0/frontend0 -> TERRESTRIAL "DiBcom 7000PC": good
>:-)
>   check DiBcom 7000PC:
>           DVB-T
>        /dev/dvb/adapter1/frontend0 -> TERRESTRIAL "DiBcom 7000PC": good
>:-)
>Using TERRESTRIAL frontend (adapter /dev/dvb/adapter0/frontend0)
>... lines omitted for brevity ...
>
>
>(time: 11:14.647) dumping lists (29 services)
>
>	So w_scan(1) doesn't do quite as well as MythTV 0.28's 43 but it is
>better than scan(1) or dvbv5_scan(1).
>
>	Cheers,
>
>	Doug

scan and dvbv5-scan rely on the config files in /usr/share/dvb/dvb-t
to specify the frequencies to tune to, and for New Zealand, those
config files are hopelessly out of date.  It might be the same for
Sydney also, in which case they will be missing one or more of the
frequencies completely and hence all the channels on those
frequencies.  You probably need to make your own updated config file.
The output of w_scan can help with that - it should see all the
frequencies that have a signal on them.

There is another problem with switching modes.  I have two DVB-S2
cards, and one (TBS 9522) will automatically switch from DVB-S to
DVB-S2 as required.  The other (TeVii S470) seems to require that the
software doing the tuning specify the DVB-S/S2 mode.  MythTV in 0.28
has the code to detect the sort of card and make the DVB-S/S2 switch
itself if necessary, but scan and dvbv5-scan do not seem to have that
ability, and also do not seem to have any options on their command
lines to set either DVB-S or DVB-S2 mode.  So unless there is
something in the config file which specifies the DVB-S/S2 mode, which
I have not found, they are unable to scan DVB-S2 transponders on using
cards that do not auto switch.  I am guessing that DVB-T2 cards may
also be built the same way, so that if their drivers do not auto
switch the DVB-T/T2 mode, scan and dvbv5-scan may not be able to scan
DVB-T2 transponders using cards that do not auto switch.  But MythTV
can.  That would only affect you though, if Sydney has any DVB-T2
transmitters - I have no idea if they do or do not.


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