I have read all about how xvmc makes everyone's PC run so much smoother. Well, when I gave it a go (R5D1), I get the black and white popups, but the playback is much worse than without it. I have an Nvidia 6200LE card. Playing HD content, it goes to about 50% CPU usage without Xvmc, about 70% when I enable it (sound gets choppy, some flicker in the video). I have tried various combinations of interlacing and stuff, the usual things people suggest on Xvmc problems without success. Might my card just not be compatible with Xvmc or something odd? This is on an Athlon 64, 3000+ processor.

I'm mostly just curious why it wouldn't work for me, when nearly everyone has such great success with it. And it is somewhat unstable when I play an HD recording while recording another. I was hoping this would stabilize it for me. As it is, I just wait until other recordings finish before I watch HD content, mildly annoying.

Thanks

ssh into the box while playing HD and run top. I have a feelling commflag is running and causing your problems.

You may want to try disableing it.

You will need to go into myth-setup to do disable it.

I had some of the same issues when I first tried XvMC with R5D1. I downloaded the latest version of the Nvidia drivers and then enabled XvMC and Bob2. Things worked great after that.

I don't have the same graphics card but it helped my situation.

From my understanding there may be issue with KnoppMyth that are running Myth 0.20 with Athlon 64bit processors. Human had been working on this problem, but I don't know what the current status is.

_________________
Girkers

Should be fixed in R5E50. Human did extensive testing of this before the release.

The upgrade hints include one simple fix for enabling the XvMC libraries.

I must be some kind of idiot but I can't find any mention of XvMC in the upgrade hints..

My bad. I added it to the fix-me list but forgot the hints... Sigh...

Edit /etc/X11/XvMCConfig and fix the path from:

to:

Credit for the fix goes to modemboy.

The above fix should be done for AMD processors only ?....

CPU Processor type has nothing to do with it. This version of the patch is for video cards with an Nvidia chipset which are using the nvidia drivers. I'm still waiting to hear if there is a similar fix for the XvMC in the SiS and ATI video drivers.

tjc,

I have done the change to XvMCConfig as per your instructions but I don't notice any difference in CPU utilization reported by 'top'. I am using KM R5E50

(corrected the typo, I'm actually using R5E50. I must get around to re-labeling that CD, then perhaps I won't keep making this error all the time )

For HD the CPU is at 95% and stuttering, especially if I overlay the channel details.
For SD the CPU is at 15% (and very smooth)

I have just used the KnoppMyth/Power off option in MythTV to power cycle my machine, is this sufficient to get it to use XvMC or do I have to start/stop the backend?

I know that my machine is probably underpowered but I was hoping it would be enough for a single tuner HD implementation. I have only just got my machine to tune the channels and so there is probably a lot still to do to tweak the performance of my box (check that DMA is enabled, etc), but even if it is underpowered wouldn't I expect the CPU % to change when I enable/disable XvMC?

Machine specs:

Motherboard: Asus A7V8X
CPU: Athlon XP2600+
RAM: 512M PC3200
HARD DRIVE: 80G IDE
VIDEO: MX440 AGP8X (Msi MX440-VTD8X- VIVO)
TUNER: AirStar-HD5000AV-PCI

thanks,

Kevin

Looking over your system specs I would say that you are underpowered for HDTV.


Not necessarily. I spent a lot of time playing with my first HDTV card - A Fusion HDTV5 RT Lite - trying to make it work right with my existing motherboard/CPU - Never did. XvMC will help, but it does not eliminate the problem of simply having too little CPU horsepower (NOTE: a CPU "on the edge" may exhibit little to no problems if an adequate amount of RAM is installed). I am currently playing with an Asus M2NPV-VM/Athlon 64 3200+/512Mb DDR2 533 combo, trying to come up with the right combination of playback settings in R5D1 to get reliable HDTV playback without pausing/stuttering. I haven't revisited it this weekend, but I believe I am close (will post in the Tier [1-3] forum when I conclude). I can tell you that a P4 3.0Ghz/HT processor in an ASRock P4i65G motherboard with 512Mb DDR RAM and a GeForce 6200LE AGP does playback HDTV smoothly for me running R5D1.

BTW, I assume the reference to R5B50 is a typo?

My result doing this, was that previously using P-in-P would blow away back to the 'penguin' screen... After I made the change P-in-P worked no problem...

I had been stutterless before (with a 3.2ghz processor) but I think enabling P-i-P indicates more offloading the processor to the nvidia card.

Slowtolearn & snaproll,

thanks for your advice. I seriously didn't expect to get away with my hardware setup, especially when I buy a 2nd tuner card. Since I wasn't even sure I could tune into the HD channels I wanted to use some old h/w and just fork out for a tuner card initially. Now I know the HD channels are unencrypted and the HD5000 works I am ready to go out and spend the cash to buy the right hardware for the job.

I don't suppose I should go on too much about the hardware, that would be taking it off thread so if you know of a good thread which is actively discussing hardware to work with R5E50 (phew, got it right that time) I would be very grateful.

'Slowtolearn', I look forward to seeing your tier1-3 post when you conclude your tests,

Kevin

bbear - Your current hardware should only hinder your ability to playback HDTV (either via Watch TV or Watch Recordings). Recording, scanning for channels, etc. should be fine as those functions don't make high demands of your CPU cycles. Again, the higher CPU requirements are strictly for HDTV playback.

You should be able to find many HDTV success stories in the Tier 1,2 forums.

Best of luck with it!

'slowtolearn',

I managed to get XvMC to work for my setup. I did not know about needing to change the MPEG2 decoder settings from the default, 'whitepines' pointed me to an article which discussed this.

I changed the preferred MPEG2 decoder settings to 'standard XvMC and one field (deintelacing) and my CPU (for HD content) dropped to 30%. This is using R5B7.

With R5E50 I get roughly the same savings, CPU dropped to 35%

I am using a ASUS A7V8X MB, with 512M PC3200 ram, XP2600+ CPU and MSI MX440-VTD8X (MX440 AGP8X VIVO)

I now get smooth playback on HD, but I do see the 'problem' with the pop-ups now being in greyscale. This in itself is not a big problem but the pop-ups make the video and audio stutter very badly. This stuttering seems much worse with R5E50 for some reason. I will do some searching on this forum, hopefully there is a solution to this.

Although smooth playback of HD is essential the problem with the pop-ups is a significant drawback in the usability of MythTv.

I know this might sound like I am being overly critical with what is aready a brilliant application but having used my Motorola DCT6412 for some time, one things that it does do well is the guide info and the video overlays. (it does however do many things far worse that MythTv manages to accomplish!)

Kevin