[mythtv] [PATCH] Enable recording of encrypted channels without decrypting them first.

[Emmanuel]

Janne Grunau a écrit :
> On Fri, Jul 09, 2010 at 10:09:01AM +0100, Stuart Auchterlonie wrote:
>   
>> On 09/07/2010 01:42, James Courtier-Dutton wrote:
>>     
>>> Hi,
>>>
>>> Here is a patch that lets one record encrypted channels without
>>> decrypting them first.
>>> It also includes the ECM PID so that the recording can be later
>>> decrypted at playback time.
>>> The main advantage of this is that one can then record as many
>>> encrypted channels as one has tuners, and then later, using the
>>> correct smart card, decrypt them while playing them back.
>>> In this way, you only have to decrypt one channel at a time.
>>>
>>> I would be interested to find out if this patch breaks anything.
>>>
>>> Kind Regards
>>>
>>>       
>> I may be missing something. but what is the point of creating
>> ProcessEncTSPacket ???
>>
>> An encrypted TS packet isn't any different from a normal TS packet
>> apart from the data portion being encrypted, as such the ProcessTSPacket
>> could be used instead?
>>     
>
> There is one important difference: the payload is encrypted.
> ProcessTSPacket() looks at the payload for keyframes.
>
> I haven't look at the patch in detail, there is nothing fundamentally
> wrong with it just one detail. Not writing scrambled TS packets is a
> good idea if there is no mean of unscramble it later and should be
> preserved.
>
> Janne
>   
I am reviving this thread as someone on the linux-media list is 
interested in implementing independant CI for supporting DVB cards; 
apparently some cards can route the stream from memory to the CI, so you 
can decode an encrypted file.
He is looking for suggestion on how to do this correctly (there are 
issues like several tuners sharing the same CI...). I guess an 
user-space app dev point of view could help.
Bye
Manu