[mythtv-users] PCTV 292e DVB-T2

[Chris Simmons]

I recently emailed about DVB-T2 tuners and contrary to what I initially 
said I got a PCTV 292e tuner :)  I am fickle...

I'm using 3.17.2-200.fc20.x86_64 (fedora 20) and there's an in kernel 
driver which basically works.

- It tunes in to DVB-T stuff fine including in mythtv
- but DVB-T2 multiplexes don't work in mythtv
- dvbv5-zap in Fedora 20 crashes but
- I've compiled latest v4l-utils and with this dvbv5-zap works and I 
recorded some HD stuff off a DVB-T2 multiplex yay!

So that's pretty good, it basically works but sadly mythtv doesn't work 
on the DVB-T2 multiplexes.  I'm sure I've got the right multiplexes 
because I previously had them working on a PCTV 290e.  I see similar 
behaviour in that tzap doesn't work with this device for the T2 
multiplexes, I think because it isn't using the dvb v5 APIs.

Has anyone got this working?

Summarizing the blog and associated links starting here

http://www.linuxtv.org/wiki/index.php/PCTV_Systems_tripleStick_T2_%28292e%29

I think what's happened is that the guy who wrote the driver didn't want 
to hack it so that it switched to DVB-T2 mode automatically. Whether 
this is a reasonable position to take I can't really say but that's how 
it is for better or for worse.  I've been rooting around the mythtv code 
a bit and it seems that there isn't support for marking a tuner as 
DVB-T2 and/or using the DVB-T2 modulation system.  It does, on the other 
hand, certainly special case DVB-S2 vs DVB-S.  There's code like this in 
dtvmultiplex.cpp but nothing analogous for DVB-T vs DVB-T2:-

     // For #10153, guess at modulation system based on modulation
     if (DTVModulationSystem::kModulationSystem_UNDEFINED == mod_sys)
     {
         mod_sys = (DTVModulation::kModulationQPSK == modulation) ?
             DTVModulationSystem::kModulationSystem_DVBS :
             DTVModulationSystem::kModulationSystem_DVBS2;
     }


I'm reading between the lines a bit but I think the solution might be to 
have a similar switches for DVB-T vs DVB-T2.

I'd be happy enough if I could get it working only on DVB-T2 multiplexes 
only as I've got a dual DVB-T tuner.

Am I on the right track here?  Any hints?

Cheers,

Chris Simmons.

PS If I do start hacking up mythbackend to get it working I'd rather do 
it on a test system.  Would I have to put it on a different subnet?  Is 
this best done in a VM?