[mythtv] Need help debugging problem with scrambled TS streams.

Anders Hanson anders.hanson at speedo.nu
Tue Jan 11 17:46:42 EST 2005


More info!

I turned on DumpTPDUDataTransfer in both MythTV and VDR and compared the 
logs.
I did the test a couple of times with the same outcome. I had both VDR 
and MythTV use the same start channel.
Everytime I started VDR it successfully tuned to the channel and after a 
couple of seconds I got a picture.
Eveeytime I started MythTV it failed.

What I can tell from the logs is that the CA_PMT that is sent fromMythTV 
is 8 bytes shorted than the CA_PMT that is sent from VDR
and that I got 'Malformed PAT' errors in the MythTV.

All other TCPDump traces are identical between VDR and MythTV.

Here is the part from the log showing the CA_PMT diffrence.

----------------------< MythTv >----------------------
2005-01-11 23:04:45.181 DVB#0 CA: CiHandler needs CA_PMT
2005-01-11 23:04:45.182 DVB#0 CA: Creating CA_PMT, ServiceID=1022
2005-01-11 23:04:45.182 DVB#0 CA: Adding CA descriptor: CASID=0x500, ECM 
PID=774
2005-01-11 23:04:45.182 DVB#0 CA: Adding stream: Video, PID=4102
2005-01-11 23:04:45.182 DVB#0 CA: Adding stream: PCM, PID=4358
2005-01-11 23:04:45.182 DVB#0 CA: Adding stream: AC3, PID=4614
2005-01-11 23:04:45.182 DVB#0 CA: Adding stream: Teletext, PID=7942
2005-01-11 23:04:45.182 DVB#0 CA: Sending CA_PMT with CPLM_ONLY to CI 
slot #0

--> 00 01 A0 2A 01 90 02 00 03 9F 80 32 21 03 03 FE 01 00 07 01 09 04 05 
00 03 06 02 10 06 00 00 03 11 06 00 00 06 12 06 00 00 06 1F 06 00 00
--------------------------------------------------------

----------------------< VDR >----------------------
--> 00 01 A0 30 01 90 02 00 03 9F 80 32 27 03 03 FE 01 00 12 01 09 0F 05 
00 E3 06 10 01 00 13 01 40 14 03 00 88 00 02 10 06 00 00 04 11 06 00 00 
00 12 06 00 00
------------------------------------------------------

/Anders Hanson


Anders Hanson wrote:

> Jesper Sörensen wrote:
>
>> Anders Hanson skrev:
>>
>>> Hi have had problem with encrypted channels for a long time now and 
>>> I'm about to start debugging mythtv
>>> to try to find the cause of problem.
>>
>>
>>
>>
>> Does it work with VDR? Does it work from the command line if you use 
>> cam_set & cam_test?
>>
> It works much better with VDR. I only got the "no right" menu with VDR 
> once when I did channel surfing
> (changed channel approx 50 times) .
>
> I have just built cam_set & cam_test from libdvb-0.5.5 but I'm getting 
> the following error when trying to start cam_set.
> 'ca device: Device or resource busy'
>
>> Did you try enabling the debugging in dvbci.cpp? It's in the top of 
>> the file:
>> // Set these to 'true' for debug output:
>> static bool DumpTPDUDataTransfer = false;
>> static bool DebugProtocol = false;
>>
> Yes, but I can't get that much out of that at the moment.
>
>> The API MythTV uses to do CA stuff can be found in chapter 8, 
>> "Command Interface" in the EN50221 standard (can be downloaded for 
>> free if you google it). The lower level parts of the API is 
>> implemented in dvbci.cpp (originally from libdvb).
>>
> Good, will download that and start reading.
>
>> Hope that helps - should get you started anyway. It's hard for me to 
>> do the debugging for you since you need access to the CAM to do it, 
>> and I do have other stuff to do as well. However, if you have any 
>> specific questions I can try and answer them, or maybe someone else 
>> on this list or linux-dvb can help...
>>
> This information will get me started, and I will try to dig into this 
> now :)
>
>



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