[mythtv-users] Personal Choices

Jarod C. Wilson jcw at wilsonet.com
Tue Dec 16 02:13:07 EST 2003


On Dec 15, 2003, at 00:31, Dale Weber wrote:

> On Monday 15 December 2003 12:07 am, Jarod C. Wilson wrote:
>> On Dec 14, 2003, at 15:06, Philippe Daoust wrote:
>>> I'm confused...  The X-Box Linux website
>>> (http://xbox-linux.sourceforge.net/news_archive.php) recently 
>>> announced
>>> support for 480p and 720p HDTV modes.  Is this because Myth doesn't
>>> actually
>>> take full advantage of the HW on the XBOX?
>>
>> They can output those modes, meaning you can spit out a 480p or 720p
>> progressive scan signal to your HDTV. But just because they can 
>> display
>> those modes doesn't mean they can decode an HD stream. It simply means
>> you can have a nice 1280x720p modeline outputting everything to your 
>> HD
>> display from your X-Box Linux system. For example, I output a 960x540p
>> signal from my MythTV box through a VGA->Component Video adapter for
>> everything (desktop, shell, mythfrontend, dvd playback, etc.), but
>> that's just the video signal, it isn't an HD stream. I can decode an 
>> HD
>> stream and display it over that signal, producing a very good picture,
>> but my processor is an Athlon XP 2600, and is being heavily taxed by
>> that process.
>
> 	OK, if I am understanding this correctly, when I set up X to use my 
> 53" HDTV
> set, I can set these HD resolutions for the screens.  Is that correct?

Yes. That's what I'm doing right now.

> I need to get one of those VGA to component adapters.  Do DVI to 
> component
> adapters exist?

Yes and no. Not all HDTVs will work with a DVI signal from a computer. 
Success is rather hit and miss. To make it more interesting, some sets 
have RGB component video inputs, some have YPbPr component video 
inputs. DVI to RGB is a straight adapter (relatively cheap), while DVI 
to YPbPr requires a transcoder (a bit spendy).

> I'd rather not use the extra adapter to adapt the DVI output
> of the second head of my Matrox G550 to VGA before adding the component
> adapter.

I use an Audio Authority VGA to Component Video (YPbPr) adapter with my 
set. It works quite well.

> The box I am currently running Myth (backend and frontend) on has
> an Athlon XP 2100+ CPU and 512 Meg of DDR RAM.

2600, 512, GF4MX.

>> Long story short, being able to do an HD display mode doesn't mean you
>> can decode HD content. The X-Box is more or less a PIII-733 with a 
>> 64MB
>> GeForce 3 and 64 MB of system memory, if my own memory serves me 
>> right.
>> Linux takes advantage of it as well as it can. The system just 
>> flat-out
>> doesn't have enough juice to do anything HD. DVD, yes, but DVD is 
>> about
>> 1/4 the resolution of a full HD stream.
>
> 	Hmmm, I have a system here with slightly better specs than what the 
> X-Box
> has, except for video..  Does that mean it may be possible to run a 
> backend
> on this box of mine?

There are people running backend-only machines on far less. But you 
*must* use a hardware encoding card in the scenario. I have an Athlon 
800 w/a GF4MX & 512MB of RAM that plays back full 720x480 mpeg2 streams 
captured by a PVR-250 just fine (as a remote frontend only, but it'd 
probably handle the capture also).

> It has 192 Meg of SDRAM and a Pentium 3/733 Mhz CPU. I
> would not think this would be peppy enough to do recording, but might 
> serve
> as a nice little frontend box.

It *might* work as a frontend-only. Can't say for certain. You may be a 
bit shy on RAM and video card (the GF4MX helps my Athlon 800 out a fair 
amount). Plenty of juice for hardware-based encoding though, if you 
wanted to make it a backend. The only way you'll know for certain is to 
try it. :)

-- 
Jarod C. Wilson, RHCE

Got a question? Read this first...
     http://catb.org/~esr/faqs/smart-questions.html
MythTV, Fedora Core & ATrpms documentation:
     http://wilsonet.com/mythtv/
MythTV Searchable Mailing List Archive
     http://www.gossamer-threads.com/archive/MythTV_C2/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: PGP.sig
Type: application/pgp-signature
Size: 186 bytes
Desc: This is a digitally signed message part
Url : http://mythtv.org/pipermail/mythtv-users/attachments/20031215/d60f566f/PGP.pgp


More information about the mythtv-users mailing list