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[linux-dvb] Re: PID's in FF and Budget cards, summary. Encryption case?



Hi,

At 09:24 9/09/04 +0300, Irek Defée wrote:

<...>
>Now there is one issue remaining still and it concerns ENCRYPTED PID’s:
> 
>When the FF card is equipped with CI, CAM and subscription card, how
>encrypted/decrypted 
>TS packets are flowing through it? 

When the external CAM is enabled, a set of tristate buffers in the DVB 
card disconnect the outputs of the MPEG2 demodulator (in the tuner) and 
connect the TS ouputs of the the CAM from/to the AV711x Transport Parser 
input port.

>...In particular:
>
>Can the DECRYPTED PID’s  be filtered out and transferred from the card
>over PCI bus? 

Yes, as already Holger have commented; I talked (shortly) about it on
the Readme.txt of the file Ttf_tsc1.zip, that today I've re-uploaded.
On the included PCB files, there is one "adapter" intended for this;
mechanically, it's to be mount as the other ("L" chaped), between the
tuner and SAA7146 pins, but now the signals are to be connected, with
discrete wires, to the CI TS output pins. If I'm not wrong, this 11 
signals can be easilly taped on the PCB vias that are located on two
*equaly spaced* sets of seven and three vias, in the left-upper side of
the AV711x (watching the DVB card by the components side and with the 
PCI connector down); the remaning via, of the "data bus", is below the
seven set. This is hard to describe but easy to see :-).

>If the CAM is able to decrypt say the allowed maximum of 32 PID’s, can
>all those decrypted PID’s be
>transferred from the card like in the case of unencrypted PID’s?

One problem is that very few CAMs will decode so many PID's :-(. While
it's common that the Descrambler in the CAM can support several PID's, 
with its related Control Words, the CAM firmware normally only support 
one Control Word (which normally imply one channel). You can the thread:

http://www.linuxtv.org/mailinglists/linux-dvb/2004/02-2004/msg00205.html


Best regards:
--
Roberto Deza Asensio
Universidad de Navarra
Data Procesing Center
rdeza@unav.es




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