[mythtv] dvb-c scanning problems

Markus Schulz msc at antzsystem.de
Fri May 11 18:16:26 UTC 2007


i've some trouble with transponder scans on my dvb-c network.

My provider broadcasts wrong NIT(-other) data, it comes directly from 
satelit and therefore is completely wrong for my cable-network.
Also scanning with a correctely prefilled dtv_multiplex list breaks all 
channels and destroys the multiplex list (all mutiplexes are updated 
with wrong [dvb-s] data).
The multiplexes will be overwritten cause the get_dtv_multiplex() (used 
inside insert_dtv_multiplex to find existing) method dont respect the 
modulation parameter for dvb. For users with DVB-c _and_ DVB-s cards 
this should be fixed too.

Whats now the best way to solve this? Make it switchable (enable/disable 
of NIT-processing)? Or better to check if NIT informations are for the 
same network type what we are scanning and drop the NIT informations if 
it was for another type? 

For the latter i've taken a look into SIScan::HandleNIT(), here this 
could be handled. But i don't know how to detect which 
network-scan-type is currently running to skip the 
ChannelUtil::CreateMultiplexes() call if desc.DescriptorTag() was 
HandleNIT seems to be called thru QT-Events, but don't find from which 
place. Can someone give me a hint?

Whats the general way for scanning dvb-[cst] with an empty mulitplex 
list from users-point of view? 
I think it would be nice to support the transponder lists from dvb-utils 
package and let the user choose a transponder list based on his region.

Markus Schulz

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