Hi,
Prompted by
tvden's post I thought I'd start a new thread about this.
Something I'll have to explain is that it's all very much "up in the air" at the moment, and exact system requirements will depend on what software is used and what features are required. Also it depends to some extent on me testing it all (and there's a lot to test) on different systems; and I've only got one system right now, and there's only one of me, too
At the moment, my full-featured MythTV PVR setup is working reasonably well on an 800MHz AMD Duron system with 256M RAM, but bits of MythTV are sluggish and off-air digital TV can take a good few minutes to settle down and stop "stuttering" after a channel-change. The MythTV developers are addressing a bug which should, when dealt with, lower the CPU load a bit and mean it settles down more rapidly.
So, as a rough estimate, an 800MHz Duron with 256M RAM or similar-spec Intel system ought to be ok for a 'basic' MythTV system running one
digital TV card. Anything less and you may struggle, but there's no harm in trying - DVD playback at least ought to work on lesser systems.
I first tried a 600MHz P3 system; this was ok playing back DVDs and was good enough to support direct unbuffered off-air TV from a basic analogue TV tuner/framegrabber card using a basic TV viewer application (
not MythTV - analogue TV with a basic framegrabber on MythTV would probably take a 1.3GHz processor.) I was unable to test the 600MHz P3 system with a digital TV card as the card wouldn't work in the particular motherboard; partly why I swapped the board for the 800MHz Duron board from one of my servers.
For some reason I couldn't get streamed video off the 'net to work particularly reliably with the 600MHz P3; but this may be down to configuration. I've not had time to work on streamed video again with the current system.
For anyone wishing to experiment; I'd suggest reading the general information on MythTV system requirements; particularly this section
http://www.mythtv.org/docs/mythtv-HOWTO-3.html#ss3.1
Any capture devices which already work with MythTV should work with MythTV on 405, 819, etc.
I'm using a Hauppauge Nova-T DVB-t internal PCI card (not the external USB version); this works fine although I've not got the bundled remote control working particularly well yet; so my system still has a wired PC keyboard on it.
Now - Graphics Cards. All I can say with any certainty is that the nVidia GeForce4 works, the nVidia GeForce2 doesn't support interlaced modes. There's some fun and games involved as nVidia have released some broken driver versions which refuse to produce proper syncs and interlace on the HD-15 RGB output; but I can confirm the latest driver does work - this is
version 1.0-8756
Theoretically, any nVidia card from GeForce4 onwards should be ok, but I've not tested them personally - again, feel free to try yourself. Other cards may work; some cards might work fine with the 405-line modeline I calculated for the GeForce4, some might need a new modeline calculating, and some may be completely unable to produce correct 405-line timings at all. This needs further investigation; I may end up asking for graphics cards on loan, so I can try them out myself.
Before I release my KnoppMyth-based custom "obsolete standard" distribution (FotH Linux), if anyone feels like experimenting with 405-line (or 441, 819, etc., when I've worked those out) from a PC; first get MythTV working on a PC monitor; then get it working with the card's TV-out (S-Video or composite) with a PAL/625 (or NTSC/525 if appropriate) set.
The easiest way I've found to do this is to install KnoppMyth (which is a complete dedicated-purpose Linux distro) see
http://knoppmythwiki.org/.
The latest KnoppMyth public pre-release (R5B7) currently contains an older (broken) nVidia driver though. At present it takes a bit of mucking around inside the system to install the
version 1.0-8756 nVidia driver. The included nVidia driver does work on a progressive-scanned PC monitor though, and at least lets you play with MythTV a bit
Additional hardware required for obsolete standards: an RGB+sync combiner circuit. I'm currently working on a Mark II version which I'll release schematics for once it's tested. Hopefully it'll be the Mark II in use at NVCF
I hope this isn't too off-putting - basically it's all still very much in the "experimental" stage - one thing where commercial software and open-source software differ is that open-source software is developed in public - you can get your hands on development software long before it's stable, complete, reliable...
After NVCF I hope I'll be able to find somewhere to host a "FotH Linux Wiki" where I and others can post information which, in the interim, will help anyone modifying KnoppMyth for obsolete TV standards and eventually become a repository for information about the FotH Linux distro itself.
Regards, Kat