[mythtv] dvb cam problems with version 0.18

phil.vid at gmail.com phil.vid at gmail.com
Fri Apr 22 08:40:15 UTC 2005

> phil.vid at gmail.com wrote:
>>>> I've been having some issues with the dvb cam operation changes from
>>>> version 0.16 to 0.18.
>>> Could you please make a PMT dump with dvbsnoop?
>> As requested:
> <snip>
> Thanks. I can't see any CA descriptors on the program level so that part 
> seems to work as intended. I don't know why you got one there with 0.16? 
> I'm a bit busy now but I'll take a deeper look at it later. Sounds like 
> you have a pretty good handle on it though so if you're impatient maybe 
> you can track it down on your self. :-)

What I have found is tuning encrypted channels will succeed when only using 
the CA System ID 0x0624. If I use 0x0604 it fails, even though both are 
reported as acceptable by the CAM earlier in the logfile.

By putting a small if statement around the elementary stream capmt 
insertion, allowing it to only send 0x0624 system id, this now tunes 


2005-04-22 19:23:11.438 DVB#1 CA: CiHandler needs CA_PMT
2005-04-22 19:23:11.444 DVB#1 ERROR - CA: GetCaSystemIds returned NULL!
2005-04-22 19:23:11.450 DVB#1 CA: Creating CA_PMT, ServiceID=1008
2005-04-22 19:23:11.457 DVB#1 CA: Adding stream: MPEG-2 Video, PID=1081
2005-04-22 19:23:11.463 DVB#1 CA: Adding CA descriptor: CASID=0x624,ECM 
2005-04-22 19:23:11.469 DVB#1 CA: Adding stream: MPEG-2 Audio (eng, PID=1082
2005-04-22 19:23:11.475 DVB#1 CA: Adding CA descriptor: CASID=0x624,ECM 
2005-04-22 19:23:11.481 DVB#1 CA: Sending CA_PMT with CPLM_ONLY to CI slot 
--> 01 01 A0 27 01 90 02 00 03 9F 80 32 1E 03 03 F0 01 00 00 02 04 39 00 07 
01 0
9 04 06 24 13 C6 04 04 3A 00 07 01 09 04 06 24 13 C6

My question is now is that is there some standard requirement only to use 
the highest system id presented or use them in any particular order? It 
seems that the failure of the 0x0604 system id is either cam specific or 
intentional by the standard but I can't find any reference.
Any conditional access gurus able to shed any light on this?

As an aside by hacking the code up like this it allows me to tune but takes 
5-10 seconds of flickery screen to finally get a picture up. I don't know if 
this is a common multi dvb card issue or just specific to this problem.


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