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

Anders Hanson anders.hanson at speedo.nu
Wed Jan 12 18:14:38 EST 2005


Jesper Sörensen wrote:

>
>>> Please try the attached patch (against patch 3.5). Unfortunately the 
>>> paths in the patch are wrong but it should work if you specify the 
>>> file names manually when applying the patch. Let me know if you 
>>> can't get it to apply and I'll try and make a new one for you.
>>>
>> I managed to apply the patch but the CA_PMT is still not identical 
>> for MythTV and VDR :( This time MythTV is sending more info than VDR!
>
>
>
> The data is not supposed to be identical, since the Autopid mechanisms 
> work a bit differently in Myth and VDR, so they may select different 
> streams, and there could be other valid differences too. So you need 
> to analyze the data and determine if the differences are okay, or if 
> they are bugs. The structure for the CA PMT is defined in section 
> 8.4.3.4 in EN50221, and in the data below I think there is a 9 byte 
> header before the CA PMT begins. I can take a look at later but I 
> don't have time right now...
>
>> MythTV --> 00 01 A0 35 01 90 02 00 03 9F 80 32 2C 03 03 FE 01 00 12 
>> 01 09 04 05 00 03 06 10 01 00 13 01 40 14 03 00 88 00 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
>
I found one small error in your patch. You forgot to add the data_len to 
in the to the descriptor_len in cCiCaPmt::AddCaDescriptor()

-capmt[length++] = 0x04;   // descriptor length
+capmt[length++] = 0x04+data_len;   // descriptor length

With this fix added to your patch I do not get the "no_right" menu but 
instead i get lots of "Malformed PAT!" the first time I tried.
Now two hours after the first test everything looks good and I have a 
clear picture from all the encrypted channels I have access to!


/Anders Hanson



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