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

[Janne Grunau]

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