[mythtv-users] Okay, slow down, HDTV idiot here...

Cory Papenfuss papenfuss at juneau.me.vt.edu
Sat Jul 17 11:10:30 EDT 2004


>>     Correct me if I'm wrong, but my understanding is that the broadcast 
>> flag is a "voluntary" (until it's mandated) thing.  The broadcast streams 
>> may have the broadcast flag set, but won't be encrypted.  In fact, the 
>> demod cards now (e.g. pcHDTV) must *still work*, so the stream can't be 
>> encrypted.
>
> The broadcast flag is just that -- a flag in the ATSC headers that indicates 
> that this material was broadcast.  Older hardware is free to ignore the flag. 
> Newer hardware must take special care to make sure it doesn't leak to the 
> internet.  It's cable TV that will have encrypted MPEG-TS.

 	... and QAM signaling.  Is it too much to hope that not all cable 
channels will be encrypted?  If a local channel is sent over the cable, would 
most cable companies encrypt it as well as throw in the broadcast flag?

>
>>     So if one were to build a receiver under the new rules and have a 
>> firewire output port spewing demodulated MPEG-TS, it must also encrypt the 
>> stream? 
>
> That's correct.  Or downsample to no better than 480p.

 	OK... that's the way I read it, too.

>
>>     If that's the case, then I'm sure it won't take too long to have 
>> "Billy-Bob's HDTV tuner with firewire output" product hacked to receive 
>> all again.
>
> Another requirement is that the implementation be "robust" against physical 
> and software hacking -- e.g. (my interpretation) no socketed or flashable 
> firmware, no accessible bus ports, etc.  Each design must be approved by FCC 
> and MPAA.  This also seems to indicate that no PC-based hardware could be 
> good enough unless it does all processing inside a single chip.  And of 
> course any attempts to distribute software that bypasses the encryption (no 
> matter how lame)--or even just strip off the broadcast flag--is prosecutable 
> under DMCA.

 	Robust is such a vague term... :)  I do believe that it will be the 
DeCSS thing all over again.  It did what was intended for awhile, but due to an 
oops and an original oversight, it was compromised.  The only difference here 
is that there's the potential for more than one "standard" of protection.  Of 
course, consumer's won't like their Sony brand HD-DVD recorder not playing 
their Toshiba recorded HD-DVD disks.

>
> I should point out that this is my interpretation of this fine state of 
> affairs, and I'm certainly not a lawyer.
>
 	Me neither, and I can't stay awake while trying to read the whole 
ruling.  I think I'll just build a software radio PCI card instead... :)

-Cory


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