[mythtv-users] HD input in the future (DVI and HDMI)

[Brad Templeton]

On Mon, Jan 17, 2005 at 04:53:59PM -0500, Sean Cier wrote:
> clarity's sake, but wanted to point out that HDMI does not mean DVI + copy 
> protection: DVI+HDCP means DVI + copy protection, while HDMI basically 
> means DVI+HDCP+Audio+BidirectionalCommunications (to negotiate formats, 

I had read a source that suggested you could not get a licence for the
HDMI stuff if you didn't promise to do HDCP, but I haven't verified that.

However, what I said remains true, their goal is to marginalize unencrypted
DVI from the market, so that so few TVs exist that can only take clear DVI
that it becomes practical to convince creators of set top boxes that they
can output nothing but HDCP based signals and not hurt their market.

Today if you made an STB that did only HDCP, there would be many problems
because of people who can't use it.  That, they plan to change.

They are currently less concerned about component video because it adds
A2D to the problem of recording it, and today that's expensive.  But
when it gets cheaper the goal is to marginalize that as well.

> Also note that there's been a lot of suggestion that HDCP is quite readily 
> crackable, quite possibly already effectively cracked; there's just not yet 
> a good motivation to distribute the cracks ala libdvdcss, since nobody 
> could yet do anything useful with the unencrypted DVI stream anyhow.  It's 
> a slightly fuzzy area since the industry(*) could fight back against *some* 
> kinds of cracks by using key revocation -- but key revocation is an 
> entirely untested technology, and is likely utterly, laughably impractical 
> in the real world.

They have developed whole new rafts of key revocation tech that, in theory,
let them revoke only the solo device that was compromised.   In addition,
now that more and more devices are getting flash card slots or even
internet connections, one can imagine regimes where, just like satellite
vendors sending out new smart cards, TV owners are sent out updates to
replace compromised keys.

With the long term goal of putting the decryption at the very last stage
before display (ie. cablecard etc.) we'll probably see this sort of
technique.

> and MPEG2 encoders which, as Brad suggested, Moore's law will inevitably 
> bring us -- will mean that HD input to our Myth boxes will be a real 
> possibility long-term, with likely the only 'hack' being obtaining a 

Rather, there will be an arms race that goes back and forth.  Today we're
in the loser category, we can't record our cable and satellite based HD
signals.   In the future, we'll move into the winner category.  I suspect
that _eventually_ we will win but they will always counter.

Consumers aren't interested in that game, only us.    Few want a
technology that can record their shows today, but might stop working
tomorrow.   I guess that's what they have in the bootleg satellite "industry."
The companies do countermeasures, ship out new smart cards to paying
customers, it goes back and forth.  Sometimes your satellite gives you
free everything, sometimes it barely gives you anything.  Since this is
a difference of paying $100/month to get the same stuff, people put up
with it -- some people.

Here, we're talking about the difference between renting/buying their crippled
but fully able to record proprietary PVR and for a not too different
price getting an open PVR which has more features but might lose the
ability to record if the key it uses is disabled.

> Of course, for OTA or unencrypted cable, using a GnuRadio card
> <http://comsec.com/wiki?UniversalSoftwareRadioPeripheral> and ATSC (or QAM) 
> software codec could result in a more elegant solution even in a 
> post-broadcast-flag era; but that doesn't necessarily work for encrypted 
> cable signals, and its legal status for OTA remains to be determined 
> (though it would have to be a pretty flaky legal decision to make that 
> hardware illegal).

The harder question is, since it was crazy to think about making hardware
illegal, is it much more crazy to imagine them trying to ban the software
too?  Decss is banned, though not by the FCC.  The FCC is overstepping its
bounds in making hardware illegal but they did it.

> Even better would be if the EFF and others succeeded in getting the 
> ridiculous broadcast flag struck down in court (well, more specifically, 
> the FCC's self-granted oversight over the entire data chain and hence the 
> entire technology industry).  And/or maybe a cable tuner PCI card that took 
> a CableCard and delivered clear MPEG2 bitstreams or, hell, even 
> uncompressed frames... hey, a guy can dream, can't he?

We hope to win that fight, but I fear it's not the last fight.  The
juristiction of congress over hardware is harder to fight.  We even lost
a battle over their jurisdiction over software.  But not the war.