Re: MythTV HD and DRM

On Thu, 2009-02-05 at 07:37 -0700, Aaron Birenboim wrote:
> I'm making an order to set up my new server, with MythTV backend.
> This looks like a very nice device, although I had a simple,
> single DTV internal card in mind.
> 
> I see many reviews that like this external, ethernet device,
> and recommend steering clear of others, so I am considering it.

I've only used internal PCI cards, (I'm using a KWORLD ATSC110)
but I also was interested in this device when I heard about it this
morning on the linux link tech show:
http://feeds.feedburner.com/~r/TheLinuxLinkTechShowOgg-vorbisFeed/~3/532176533/tllts_284-02-04-09.ogg

There is a -$20 discount code for it right now:
http://www.xpbargains.com/index.php/send_deal/103036

> All I'm looking for (at first) is a card to tune over-the-air
> digital TV (MPEG2) and record it.
> Perhaps de-multiplex and record only the sub-channel/audio/cc
> I want.  (Are things like KOB 4-1 and 4-1 multiplexed in a single
> stream?)

When I change channels from eg. 4-1 to 4-2, mythtv gives a message like
"changing to 4-2 on same multiplex" or similar, so I think the answer is
yes.  

> AFAIK, the un-transcoded HDTV bit rates are well within
> modern storage and bandwidth capabilities.
> (Correct me if I'm wrong)

I'm inclined to take issue with the use of "well within"
it's fine but it is sometimes really really big. I've got a AMD XP2500+
and ~200GB of storage space. And both are significant handicaps to the
usefulness of the box. But if you're building a new box you should be
fine.

> I'm having a hard time finding simple cards for this use.
> (I don't fully understand all the acronyms they throw around)
> It seems that most cards will digitize analog, perform display...
> All I want is something to tune the digital stream, and record it.
> Un-transcoded is fine.
> I can transcode on the CPU if necessary.  I plan to get a 3-core AMD.

In case you've not yet discovered the magic word that means over-the-air
digital in North America, is "ATSC" (DVB-T is in other parts of the
world and QAMxxx is something to do with Cable or Satellite.)

> I don't know what might be classified as a "pcHDTV" card... is that
> specifically designed for MS media center programs... or does that
> mean
> ANY internal PC tuner card?

That's a specific brand.
http://www.pchdtv.com

> If you think that the external Ethernet tuner is the best way
> to go for my simple needs, I'll go that way....
> but I might be interested in trying a cheap, digital tuning only
> internal card first... if I can find one.

Try listening to that TLTS show I linked above, I've only listened to
the first 20 minutes or so (and the quality of the show is no better
than it ever is :) but it is a recent conversation on exactly this topic
with at least anecdotal discussion of several different cards from
several of the major vendors.

I'm not sure why DRM is in the subject line, so far there doesn't seem
to be any encryption on the broadcast networks ATSC signals. However
there does appear to be encrypted broadcasts over ATSC of some channels
that are not available on analog over the air like ESPN and DISCOVERY.
I've been guessing that these might be being received on cell phones
that advertise that they have TV reception, but that's just a guess.

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