[mythtv-users] What's the point of MythTV HD?

Ken Mandelberg km at mathcs.emory.edu
Tue Dec 4 02:23:02 UTC 2007

 > "Tom Dexter" <digitalaudiorock at gmail.com> write:
, Ken Mandelberg <km at mathcs.emory.edu> wrote:
 > > What's really missing here is a cable card HD tuner that MythTV could
 > > access. A cablecard hdhomerun would be optimal, and since CableLabs has
 > > blessed DTCP-IP it seems that one is possible. This would work a whole
 > > lot better than renting an expensive HD cablebox and manipulating it
 > > with a blaster to get a single channel of flakey firewire output.
 > >

 >I see this mentioned quite a bit and my first thought is usually
 >"don't hold your breath".  If cable card HD tuner that could be
 >accessed by open source projects were made available, it would
 >essentially obsolete all the encryption used by cable companies...it's
 >just not going to happen.

The DTCP-IP protocol is the ethernet version of the same DTCP protocol 
that the cable companies use on the firewire port. It wouldn't obsolete 
the encryption any more or less than the firewire does, and would use 
the same CCI criteria that they do on firewire. If the destination box 
could not authenticate (which the open source boxes can't) it would only 
get the CCI=0 (copy freely) content, as it does on firewire. Closed 
boxes that are certified by Cablelabs (like Vista MCE) could complete 
the cryptographic handshake and get the CCI=2 (copy once) content (as 
they can now over firewire).

The big advantage to MythTV users would be the ability to add a 
multi-tuner HD with a reliable data and control connection, with the 
only rental fee being for the cablecard(s). Most non premium content is 
CCI=0, a large amount compared to the QAM uncencrypted content.

I think the main obstacle is that the Cablelabs certification process 
may be too expensive and cumbersome for small companies like Silicondust.

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