[GRLUG] MythTV

[Tim Schmidt]

On 10/16/06, Michael Mol <mikemol at gmail.com> wrote:
> Several members of the GRCC Computer Club want to build a MythTV box,
> but the components are prohibitively expenseive.  Any recipes for a
> budget MythTV box?

Unfortunately, with MythTV, you tend to get what you pay for.  The
cheapest tuner I feel OK reccomending is a PVR150...  They require a
bit of setup as mentioned earlier.  eBay helps.  The cheaper
BTTV-based cards don't produce great output.  They're OK, just not
great.

Skipping TV-Out saves cash too...  Not too hard to watch TV on a
monitor - so long as it's big enough.

A backend machine with a PVR-series card need only be a few hundred
megahertz.  Faster, of course, is better - especially for transcoding,
commercial detection, etc.  Similarly, ram need only be as much as
your base distribution wants plus a little extra (mysql and
mythbackend can probably coexist fine in 32Mb).

A frontend needs only to be fast enough to decode the type of video
you're dealing with - MPEG2 for the PVR-series cards, MPEG4 for
transcoded or downloaded stuff...  anywhere from 500Mhz to 1.5Ghz
depending on CPU type, and whether or not the graphics driver can do
XvMC.  Again, low memory requirements.

A combined frontend / backend machine needs to be fast enough to
encode video, decode video, and manage a database at the same time -
with a PVR-series card, encoding is done in hardware, decoding needs
are the same as the frontend, tack on a hundred Mhz or two, and a tiny
bit of ram for mysql.

I've built quite usable combined machines with BTTV-based cards (which
do nothing in hardware - all software) on an Athlon XP 1800+ (1533Mhz)
w/ 256Mb ram.  The current setup is a C7-based frontend with 256Mb,
and a Celeron 1.3Ghz machine w/ 384Mb backend.  Still stuck with a
crappy BTTV-based card.

For really nice systems, the Plextor TV402U is an external USB2 tv
tuner that does MPEG2 and MPEG4 in hardware...  saving some disk space
compared to the PVR-series cards.  They're $200 MSRP unfortunately.

--tim