[mythtv-users] Can a pcHDTV record standard definition?

R. G. Newbury newbury at mandamus.org
Wed Dec 13 15:23:52 UTC 2006

Robert Tsai wrote:
> On Tue, Dec 12, 2006 at 08:58:12PM -0600, Brad wrote:
>> On Tue, 2006-12-12 at 18:49 -0800, Robert Tsai wrote:
>>> You don't have to upgrade your cable box if you can get OTA HD
>>> signals.
>> But then when I recorded something off of cable my CPU would be
>> doing the work instead of the card right?  I guess I could try to
>> schedule cable shows to record on the PVR and shows available OTA HD
>> to the pcHDTV.
> The pcHDTV can record QAM, which requires a digital cable subscription.
> The pcHDTV can also record OTA, which only requires OTA reception.
> You get to pick one.

Not quite correct.
Cable. at least in North America, gives 3 choices:

(1) analog (NTSC) SD channel
(2)  digital (ATSC) SD channel, usually QAM256 encoded, and
(3)  digital (ATSC) HD channels usually encrypted, but may be 
unencrypted  (and QAM256 encoded) if FCC mandated (not available in 

Frame grabbers receive (1) and require CPU power to encode the stream to 
PVR cards receive (1) and have hardware encoders to create the output 
The HCHDTV HD3000 card will receive (1) but does not contain a hardware 
encoder: it needs CPU power to create the output MPEG stream. (I think 
the HD5000 is the same).
The HD3000/5000 will receive (2) as they do QAM256 decoding. Most cable 
co's. have free digital streams (but they may only be available on an 
'extended subscription...not to be confused with an HD subscruption.)
Fro example Rogers Cable provides about 30 QAM256 digital SD channesls 
and about 70 free audio only feeds on an 'extended' subscription. (This 
is out of a total of 464 digital streams!)

Encrypted HD streams (3) require a subscription and a Set-Top-Box or 
Cable-Card to decrypt. Output is usually by firewire from the STB. 
HD3000 cannot handle the decryption, although it probably can receive 
the stream.

And, using a completely different methodology, the HD3000 can receive 
both SD and HD digital broadcasts using an antenna..(OTA)...Free for the 
price of the card and the antenna.


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