[mythtv-users] Re: New MythTV Hardware Review

Brad Templeton brad+myth at templetons.com
Mon Dec 6 19:23:43 UTC 2004

On Mon, Dec 06, 2004 at 09:04:47AM -0500, Joseph A. Caputo wrote:
> On Monday 06 December 2004 02:54, Brad Templeton wrote:
> > Sadly, the protocols include copy protection, so no open source
> > decoding of the firewire stream.   In theory, if they do
> > non-protected firewire on the broadcast shows you could get that.
> I thought they were required to provide access to the decrypted signal?  
> The deal was (IIRC) that devices not honoring the broadcast flag could 
> have unencrypted firewire access, but it would be 'downsampled' to 
> 480p, so you can get SD but not HD out of your box.

I am not sure they are required to provide access to this, but you
are correct, SD outputs are not prohibited by the rules, both SD
digital and analog.   Actually, analog HD outputs are also permitted
(and expected to be common until every TV has HDMI and HDCP) so the
great question people wonder is how long it will be until Moore's law
creates an inexpensive chip that can encode HDTV analog to a compressed
format in real time.

Problem is, if you do that, then you are transcoding.  The result will
be bigger and lower quality than the incoming digital stream that
generated the analog for you to re-compress it.   (Well, perhaps with
mpeg4 this can be corrected a little bit, but it will always be a bit lower

So how will the open PVR compete with the locked PVR which, after all,
need only be a very low powered box that records digital streams and
plays them back to a TV that decodes them?  It's tough.

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