[mythtv-users] Newbie Questions

R. G. Newbury newbury at mandamus.org
Fri Dec 15 21:27:41 UTC 2006

Brett Kosinski wrote:
>> 1.) Digital vs. Analog Cable
>> I am in Canada with Shaw as my cable provider.  There is not broadcast
>> digital service and I would not expect it anytime soon given our 
>> draconian
>> government controlled TV system.  I would like to make the jump to 
>> digital
>> cable but I want to make sure I can still use my PVR.  If I subscribe to
>> the service does the PRV tuner basically replace my providers tuner box?
>> i.e. it can tune into the digital channels?
> No.  You'll feed the output of your digital cable box into your MythTV PVR,
> and control it via an IR blaster-type device (so Myth can perform channel
> changes).  This is because the digital cable feeds are encrypted, so 
> there's
> no way to feed them directly into the Myth box.  This also, incidentally,
> makes HDTV out of the question.
NOT entirely true.

In North America, all digital feeds are QAM256 encoded but not all are 
encrypted. Rogers in the greater Toronto area, provides about 30 encoded 
but unencrypted digital channel feeds plus about 70 stereo audio feeds. 
The other 364 digital streams are the encrypted ones.

If you have an ATSC capable card, such as the pchdtc HD3000 or HD5000 
you can receive and record those 30 TV channels with mythtv. The quality 
is standard definition. You do not need a set top box and you can use 
lirc and your usual remote, if your case has an IR receiver.

Big question is whether or to what extent Shaw puts unencrypted digital 
feeds on their cable. You probably need, at the least, to have a full 
analog subscription...about 70 channels or so!

You can bet that NONE of the channels you might receive will be HD. For 
that you do need the set top box etc....and unless the STB has a 
firewire output, (which is not a requirement in Canada, damn CRTC 
*spit*) you will not be able to record from the STB.

You can have any reasonable number of analog tuners and record the 
analog channels from your cable with those. I have a PVR500 card with 2 
tuners for analog and an HD3000 for one digital tuner. I can record all 
three at once, and watch a recorded program at the same time, on the TV.

These are all at standard definition levels and you do not need 2 STB'
s. You only need an STN for encrypted (generlly HD) special channels.

Note that Canada will eventually be going digital and an HD3000 will 
pick up digital broadcasts with an antenna.

Front end/backend...the problem is that the requirements are different 
in terms of size and noise, so it is sometimes better to have a big 
backend for the tuners and disks, and a small front end which is quiet, 
for placement near the TV.
But you can have a small quiet PC in the l;iving room doing both. I have 
an EPIA SP13000 motherboard, 3 tuners, one hard drive and the DVD is the 
noisiest part when its running and the power supply fan is barely 
audible...My wife hates the bright blue power LED...Its basically the 
same size as the stereo receiver which sits on top of it... the receiver 
is hotter than the mythbox... and has more lights..The receiver powers
the speakers.

Go to the myth site and browse through the wiki. There is lots of info 
there and in the gossamer-threads lists...which are searchable....


> Incidentally, I'm also on Shaw Cable and have a Motorola DCT-2524.  It 
> works
> beautifully with my blaster from irblaster.info and the DCT2500 remote 
> codes
> (and quickly, after I removed the delay between clicks in my channel
> changing script).
> 2.) Dual tuners
>> Can I have two tuners and record 2 shows at the same time?
> Yes, but you'll need two cable boxes and two IR blasters to do it.
> 3.) Front End vs. Back End
>> I recall reading that the ideal solution would be to have a dedicated box
>> to record content (i.e. tuner cards, host the database etc) and a 
>> separate
>> box to watch TV / content.  Is it realistic to not just build a high end
>> system with lots of RAM etc and use it for both?
> You could, but then you'd have this big, hot, noisy PC in your living room.
> The advantage of a split system is that you can have a big BE with fans and
> hard disks whirring in some closet somewhere, while your FE can be small,
> quiet, and stylish.  But it really is a matter of preference.

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