[mythtv-users] many questions from a MythTV newbie

[R. G. Newbury]

Peter Watkins wrote:
> Daniel Jarboe wrote:
>> First time posting to this list.  I've recently been looking at
>> requirements for a new MythTV box for HD.  I currently tune HD with a
>> cable converter, but may be switching to ATSC soon.
> 
> There's a good chance that your cable feed will give you the "local" HD
> channels as usable QAM channels. My indoor ATSC antenna can't capture as
> many local stations as my cable company provides in unencrypted QAM (one
> local station is neither in unencrypted QAM nor tunable with the indoor
> antenna and ATSC).
> 
>> Frontend/backend:
>>
>> I'm leaning toward frontend/backend setup to keep drive/fan noise in
>> living room at a minimum.
> 
> I've got an Antec midtower with a 120mm case fan, stock Athlon64
> sink/fan and an Antec TruePower power supply. While I don't have access
> to a SPL meter, it's fairly quiet, probably as quiet as the cheap home
> theater in a box DVD/receiver with its always-on ~30mm case fan that
> I've got. My advice: it's not much more expensive to build a fairly
> quiet PC, so build your backend with a fairly quiet case, fairly quiet
> drives, and a fanless vid card like an FX5200 and see if that's good
> enough before spending more on a separate frontend.
> 
>> Any idea approximately what kind of network thruput would be required?
>>  The back of the envelope type network calculations in the MythTV
>> Howto looked to be for non-HD.  The captured files would be shared
>> over NFS unless there is some other recommendation.
> 
> 100mbit wired would be fine. You could put one device on a 802.11g wifi
> connection, but probably not both. My HDTV/ATSC recordings seem to clock
> in around 6-7GB an hour, or ~ 16 megabits/second. With backend and
> frontend both using wifi, that's 32 mbit/s before you consider network
> and MythTV protocol overhead. Most 802.11g clients don't get a full
> 54mbps connection. BTW, it's easy with NTSC standard def capture cards
> like the Hauppauge PVR-x50 series to get SDTV recordings that take as
> much space & bandwidth as HDTV, and you may want to do that (if you have
> any SD tuners), especially for shows that are broadcast letterboxed --
> zooming in on a low bitrate SD recording with an HD set can be ugly.
> 
>> Capture Cards:
>>
>> I like that the pcHDTV-3000 and DViCO FusionHDTV Lite 5 reportedly do
>> ATSC, QAM, and NTSC.  Is anyone aware of any compelling differences
>> from a usability perspective?  Do they both work well?  Similar
>> ease/challenges with configuration?  Would you be indifferent?
> 
> I can only speak about the HD3000. I've been fairly happy with picture
> quality for ATSC. Haven't worked much with QAM yet. But I think the
> HD3000 has one of the worst physical designs -- the coax jack doesn't
> stick out far enough from the back of the card, so very few coax cables
> will screw onto the HD3000 jack all the way. Compare pics of the HD3000
> to pics of others like the AverMedia A180 or Air2PC HD5000 and you'll
> see what I mean. I expect my next HDTV capture card will be an AverMedia
>  A180 card; for less than half the cost of an HD3000, it seems worth
> checking out.
> 
>> Should there be no trouble with just stereo sound for the HDTV
>> broadcasts?  My audio receiver does not support digital audio inputs. 
> 
> Should be fine; I use the stereo RCA inputs on my TV.

You must understand that the hd3000 does not go a good job in NTSC mode, 
as it has no hardware encode/decode capability. You have to use the box 
and software to deal with the signal...The Hauppauge cards, on the other 
hand have that built in, and therefor feed the same digital stream as 
the HD card does in ATSC to the bus.
Therefore my small/quiet Via SP13000 can record 3 simultaneous programs: 
2 in SD from a PV500 and 1 ATSC from the HD3000. Note that this 
motherboard does not do full HD... it is limited to 1024x1024 on TV out 
(but the internal video to monitor will do 1980x 1080 and uses Xvmc.

Tradeoffs....compromises.

Geoff