Dominique Dumont wrote:

Hello

Here are some explanation provided by a CAM developer.

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Subject: Re: [vdr] Querying CAM doesn't work From: marc.abramson@free.fr Date: Mon, 29 Aug 2005 12:40:15 +0200 To: vdr@linuxtv.org

To: vdr@linuxtv.org CC: Dominique Dumont domi.dumont@free.fr

Hello Klaus.

you are 100% right. The EN50221 spec does clearly define a QUERY procedure. However, this query is not correctly handle by a lot of module, because for a lot of different CA_smart_card, the only way to be 100% sure if the smart card is able or not to descramble something is to request a real descrambling. But then, if it works, it means that the smart card will also have started to descrambling, and also (depending of what was in the encryption message), to use token or the card, or to start a preview...

From all the CA_system I know , there is only one CA system for which the smartcard itself allow a query that will not start "consumming" anything, but only answer the query. ...

Hello Marc,

thanks for these in-depth infos.

So this means that in a device with more than one CAM that provides a given decryption method, VDR will have to explicitly try to start receiving the desired channel on each of them, and take the one that actually delivers data. Well, so much for "standards"...

Klaus