LinHES Forums :: View topic - Abit NF7-M / pcHDTV / built-in GeForce MX

LinHES Forums http://forums.linhes.org/

Abit NF7-M / pcHDTV / built-in GeForce MX http://forums.linhes.org/viewtopic.php?f=9&t=2509	Page 1 of 1

Author:	Liv2Cod [ Sun Sep 26, 2004 1:00 am ]
Post subject:	Abit NF7-M / pcHDTV / built-in GeForce MX
I finally have a functioning Myth box based on KnoppMyth and the following hardware: Abit NF7-M mainboard (incl. IGP video and MCP audio) Athlon XP 2500+ processor (Barton core) pcHDTV tuner card 200G hard disk (1) and 250G hard disks (2) LiteOn wireless keyboard This system is hooked to a rear-projection HDTV monitor and provides the main viewing experience for the home. The Abit motherboard includes the nForce2 chipset along with the nVidia IGP (integrated graphics processor) and MCP (media control processor). It has optical S/PDIF out, which I use to drive my receiver (which does DD5.1 decoding). I'm using a Pioneer PRO-610HD television which has a VGA input in addition to component video. The VGA input is locked to 1920x1080 interlaced, so that is the only video mode I'm using. (It makes the XF86Config-4 file shorter!) I encountered significant difficulties at a couple of points. First I tried using an RF Versapoint wireless keyboard/mouse device. It was a USB keyboard/mouse combo and it would NOT work as the only keyboard on the system. I had no end of troubles and ultimately solved it by getting the LiteOn unit which I highly recommend. The installation of KnoppMyth was pretty straightforward. I opted to use LVM for the /myth partition so that I could add disk space easily as well as distribute (stripe) files across the volumes for better performance. The best reference I found here: LVM HowTo Next I had a black screen when trying to view HDTV. I had installed the pcHDTV kernel as described in cesman's note in the file /usr/src/debs/pchdtv-kernel/README but I had missed the all-important detail when using the pcHDTV card: your video source must be /dev/video32 to use the ATSC tuner card. I had difficulty configuring audio as digital out but ceenvee703 set me straight in the excellent article DigitalAudioHowTo. Now I get digital audio out of the optical connector which is piped into my Pioneer VSX-39TX receiver. All decoding of dolby digital and A/D conversion is handled by the receiver. (And I avoid that horrible PC speaker BEEP that comes out my analog audio out at system boot.) My remaining issues are related to image quality and ease of use. My only interface is through the RPTV set. Overscan is a fact of life with TVs and the setup menus of Myth are a son-of-a-gun to use when you can't see the edges of the screen. The nVidia XvMC driver (6111) is working pretty well now, but I still see less-than-perfect performance when it comes to HDTV display. Most annoying is that my 1080i sources (CBS, PBS, NBC) are displaying pretty well but 720P sources (ABC, FOX) are displaying at half speed! It looks like something is passing bad information to the MythTv player that causes it to think the frame rate is only 30Hz for 720p. There are also issues with the handling of interlace video at 1080i. None of my problems are in the domain of KnoppMyth. My installation of KnoppMyth V4R4.1 and subsequent update to V4R5 went very well. All problems reside squarely in the MythTv or nVidia domains. Overall, my system is VERY usable and will only get better as I fine-tune it. Joe Barnhart

Author:	Liv2Cod [ Tue Oct 19, 2004 2:43 am ]
Post subject:
A short followup here... The built-in video of the motherboard is limited to AGP 4x and it was just a little too slow to handle my 1080i output format. I got some relief by adding a nVidia GF 5200 card that supported AGP 8x. It still wasn't quite enough speed to handle HD smoothly with the Athlon XP 2500 processor, so... First I tried an Athlon 2800 I have in another system. Not enough difference to worry about. I then got an Athlon 3000 and tried it out. All of these processors share the 333 MHz FSB of the Barton core. The 3000 was just barely hacking it, but I didn't think I would be satisfied when flagging two or three shows, recording another and watching 1080i at the same time. The sad fact is I can't get hardware decoding working under Myth very reliably (XvMC) and I'm not sure when or if it will be corrected. I still think the Abit NF7-M is a heck of a board for Myth, but HDTV is probably best done on Intel P4 right now. It just has a slightly better instruction set for software decoding of MPEG, and that is critical since I'm stuck with Xv and software decoding for now. Mind you, nothing said here affects you if you are not using a pcHDTV card and viewing the shows on an HDTV monitor. It is strictly the amount of decoding -- and the fact that XvMC doesn't work reliably -- that indicates a P4 solution.

Author:	Xsecrets [ Tue Oct 19, 2004 8:41 am ]
Post subject:
I haven't really followed anyone but you trying to use the pchdtv card. is xvmc not working properly just something that you ran into, or is it just a known fact that it doesn't work reliably with mythtv?

Author:	Liv2Cod [ Tue Oct 19, 2004 10:45 am ]
Post subject:
The XvMC issue seemed pretty well known on the myth-users list. I was told by the developers of the HDTV code that they don't use it much. It has problems because it doesn't fit the Myth video architecture very well. This is particularly with nVidia cards, I have no idea of other XvMC implementations work better. But you can pretty much write off XvMC on nVidia and HDTV.

Author:	Xsecrets [ Tue Oct 19, 2004 3:59 pm ]
Post subject:
well as far as I know nvidia is the only one that supports xvmc at all, I think I heard about a new driver for the epia that does xvmc, but that's very new. So you are probaly going to have to have a 3+ Ghz proc to run hdtv? That sucks, I was wanting to try out hdtv, but I certianly cannot afford a new proc along with the pchdtv card and vga -> component converter. and I don't see that changing before the broadcast flag restrictions come into play. I guess I'll have a useless hdtv card for a while.

Author:	Liv2Cod [ Tue Oct 19, 2004 11:40 pm ]
Post subject:
Not to worry. If you have the pcHDTV card you've already beaten the broadcast flag deadline. The XvMC thing just has to be fixed at some point. It's just too good an idea not to. I'm just impatient and want my system right now, so I went for the P4 motherboard.

Author:	Xsecrets [ Wed Oct 20, 2004 12:15 am ]
Post subject:
well I'm going to try to get a pchdtv card if they ever start selling them again. Have you had yours a while or did you find somewhere else to get it?

Author:	Liv2Cod [ Wed Oct 20, 2004 1:21 am ]
Post subject:
I've had mine a couple of months. Just got around to building a myth box around it, tho. The good news is that they're now taking orders for the new HD-3000 card for deliveries beginning Nov. 8th. I'm eager to get one or two more, since they're pitting shows like NYPD Blue and Law and Order against each other in the same timeslot. I think three would be optimum...

Author:	Xsecrets [ Wed Oct 20, 2004 8:09 am ]
Post subject:
Man it must be nice to have as much money as you want to throw at your mythbox.

Author:	Jet_Jaguar [ Thu Oct 21, 2004 4:54 pm ]
Post subject:
I can't afford all this hardware, but I'm really interested in seeing how an athlon64 would do.

Author:	tjc [ Thu Oct 21, 2004 5:26 pm ]
Post subject:
Click over to http://www.gossamer-threads.com/lists/mythtv/users/ and search for Athlon64. There are a couple threads discussing experiences with using them to run MythTV.

Page 1 of 1	All times are UTC - 6 hours
Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/