[mythtv-users] I need to specify which channels are recordable by which dvb-s2 card

[Andre]

On 29 May 2011, at 15:38, Emmanuel wrote:

> On 29/05/2011 10:18, Andre wrote:
>> On 29 May 2011, at 14:09, Emmanuel wrote:
>> 
>>> Hi all,
>>> I have a problem to schedule my recordings: I have only on sat with 5
>>> TPs, 4 of which can be recorded by my 2 dvb-s2 cards, but one which can
>>> only be recorded by one of my card (it has a very high symbol rate of
>>> 45Ms/s which is unusual for dvb-S2 and the "old" cant tune to it).
>> I'm guessing you are the Manu who has been trying to find a high symbol rate DVBS2 card for some time?
>> 
>> Which one works???
>> 
>> I'm sure there will be many more wide transponder high rate muxes in the coming years as existing satellites are replaced.
> How did you guess ;-)

There are not so many Manu's on every satellite & TV forum that want 45MSym/s DVBS2 cards for Linux :-)


> The card that works: TBS6921, it is a taiwanese card which, for now, 
> works reliably, locks fast even to the 45MS/s DVB-S2 (QPSK) TP. It is a 
> PCI-E (1x) card and  I think there even is a dual tuner one, probablu 
> 6981. If you are interested make sure you choose the 6xx1 cards (there 
> were 6xx0 cards which are not as capable for hight rates). They are 
> rated for 45MS/s DVB-S2 and it works!

Great, thanks, The SatixS2 card I have "says" it's rated for 45MSym/s but I don't have 13E or 1W available and subscriptions to test high rate transponders.


>>> So I want to be able to tell the scheduler to schedule the problematic
>>> TP only to the new card. One more information: I only have one source
>>> and each card has a lnb input, so they can tune to different TPs at the
>>> same time.
>> This is the same problem as having a mixture of DVBS&  DVBS2 cards as I have.
>> 
>> You need two sources, one with all channels from the ordinary card (delete the high rate muxes if they are detected) and another with all the channels including the high rate mux ones. You link the reduced channels source to the ordinary card(s) and the second complete source to the high rate capable card(s).
>> 
>> You should add the cards in order starting with the least capable and adding the more capable high rate card(s) last. This way when programmes are scheduled the less capable card is used if it can be and the low rate card is skipped over if high rate mux channels are needed. This reduces the chance of the high rate card being busy with a low rate channel when a high rate channel is wanted.
>> 
>> Provided you have the same callsigns/names for the channels in both sources (which you will from a straightforward myth scan) they will schedule shows on either card but not both. The listings pages will just show listings for the lowest channel number that matches the channel callsign/name.
>> 
>> I would create the source for the low rate only card first and scan, then create the source for the high rate capable card and scan, that way the best utilisation of cards will happen automatically.
>> 
>> Here is a thread about the best way of deleting and re-creating cards&  sources.
>> 
>> http://www.gossamer-threads.com/lists/mythtv/users/260095#260095
>> 
>> Andre
> OK thanks. Just to sum up: you get two lineups then?

Yep.


> That does not 
> bother the scheduler apparently.

Not at all, I have three, extra one is for DVBT, when I get DVBT2 there will be four sources. It is important to create everything in the right order but the thread i linked talks about this, there are many UK Freesat & Freeview threads that essentially discuss a similar problem, same channels from cards with different capabilities.


> I also guess that I need to directly 
> modify the DB (for eg delete a TP for the first card).

You can just delete the channels or the mux from the channel editor, no need for dirty hands in mysql. :-P

Probably the scan won't detect those channels anyway, unless the card can sort of receive those muxes! If you scan the source with the right card probably it will do the right thing anyway.

> I was thinking of 
> patching mythtv to think that my old DVB-S2 is not DVB-S2 capable, that 
> could also work, but with the burden of maintaining the patch forever I 
> guess.

Not necessary, if you did this you would not get other DVBS2 muxes that work fine, I think there is some similar problem with North American Turbo PSK modulation, some DVBS cards do it some don't some DVBS2 cards do it some don't. It's only necessary to create sources with overlapping channels that are correct for each type/ capability of each card, the VDR boys have some big problems coping with this permutation, need patches and custom tuning files! 

Myth already copes with this situation, in fact much more, my DVBS card has broken lnb signalling but it works on the BBC HD mux so I just delete all muxes in high band or horizontal for this source and the scheduler uses another card for other channels but uses this "broken" card first if BBC HD or other low band vertical mux is wanted :-) 

> Anyway thx alot!

No worries, glad you found a 45MSym/s card, I think maybe I will need one next year or the one after when we get new satellites for DTH in the UK!

Andre