[mythtv-users] XvMC - Nvidia isssues?

[Dan Seddon]

mike choy wrote:

>Dan Seddon wrote:
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>>Hi
>>This is my first post to the list after getting my system up and 
>>running. I have a Mythtv setup which I'm really pleased with it's 95% 
>>perfect! However - that remaining 5% is always worth persuing so... I'm 
>>using XvMC which means my Athlon XP 1600 trundles away at 15% usage 
>>whilst playing DVB-T (standard definition PAL) video. This has 3 issues 
>>which reading through the list have been mentioned on and off - but I 
>>haven't found all the answers.
>>
>>First off - the menus become monochrome, which isn't a biggy and worth 
>>putting up with for the performance gain (but it would be nice to know 
>>if this is preventable).
>>
>>Secondly the menus cause the video to jump when they appear, which can 
>>be very distracting -  this has been mentioned a lot on the list from 
>>what I can see. Hopefully I have something useful to add here.... I have 
>>Quadro FX500 card (don't ask why I'm sticking such an expensive card in 
>>a PVR box) and I found enabling overlays ( |Option "Overlay" "true") 
>>|gets rid of this problem - this is listed as a quadro only option and 
>>I'd be interested to know if anyone has success with this option using a 
>>non-quadro card, as I could then sell it as I've been intending to do.....
>>
>>Lastly the problem which I count as my final 5% - I have an issue with 
>>some programs where the video stutters (the video may stutter in time 
>>too, but it's hard to tell when your ears are hurting). It's been a 
>>complete bafflement to me as it happens on only some programs (not 
>>channels) and non of the configurations I've tried get rid of it (other 
>>than diabling XvMC) - playing the same .nuvs with mplayer reveals that 
>>the only unique characteristic of these recording seems to be that the 
>>audio is at 256 kbits, whereas most of the other recording I have are at 
>>192... I haven't been very scientific in checking it - but it seems to 
>>be consistant, having checked a few recordings. It happens to about 1 in 
>>5 recordings, or maybe less, at the moments - but is fustrating as I 
>>have to go in to my options and reconfigure everytime I want to watch 
>>such a recording. I've only seen this issue posted once by a guy who 
>>said he was using the via equivalent of XvMC (I haven't found his post 
>>again - as it was a while ago) - which might be important as is implies 
>>it isn't a driver problem (I get the same issue when running the 
>>frontend on my laptop with a completely different sound card and older 
>>Quadro card). Is anyone else familier with this problem? I'm in the UK - 
>>where we don't have HDTV yet, so I can't be that my systems overwhelmed 
>>by what I'm throwing at it?
>>
>>Any help/interest would be appreciated.
>>
>>Dan
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>>mythtv-users mailing list
>>mythtv-users at mythtv.org
>>http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>>
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>Dan Just so we are all in sync, what version of the driver are you using?
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I'm fairly certain I'm running 8178 (stuck here at work) - though I 
stepped through 7667-8178 to see if this effected things, with no 
obvious difference. Is there a concensus on the best driver to use?

>Also on the video stutter thing, it might be the problem with mainly 
>white or mainly black screens problem
>that a lot of people have had issues with on DVB which manifests itself 
>as an audio stutter as well. You see it
>most during adverts which use blank screens alot. The fix to this seems 
>to be to move to TS rather than PS stream processing on your dvb card.
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Yes, I know of this problem, it differs to the one I'm mentioning  - I 
seem to get it mainly with libmpeg maybe partly with Mythtvs decoding, 
but I don't think I get is at all with XvMC (unless I'm mistaken). In 
fact on the whole I get much smoother playback with XvMC (it's just what 
I mentioned which is a problem). Though, since you mention TS is the 
cure - I should check my mythtv-setup again as Justin mentions this too 
and that I get the black frame problem implies I may not have it enabled 
as I thought.

>Meanwhile I'll go and have a look at my rig on the XvMC overlay thing 
>and report back. I dont use it at the mo cause I like colour menus, the 
>machine running at 15 to 30% is no big thing to me as its not doing much 
>else.
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Yup - colour menus are nice ; ) Though, I do find XvMC is smoother 
generally with my machine + HDTV is imminant in the UK and I don't fancy 
my chances of getting it to run on my current CPU without a leg-up from 
my video card.... I've just been glancing at a few options in the Nvidia 
help though and I noticed this hidding in what seems like the wrong section:

|Option "XvmcUsesTextures" "boolean"|

    Forces XvMC to use the 3D engine for XvMCPutSurface requests rather
    than the video overlay. Default: false (video overlay is used when
    available).

Could be of use for getting the menus not to jitter (on non-quadro) and 
maybe in colour too..... There is also CIOverlay (indexed colour) but I 
couldn't get that to do anything : (

Thanks for your help!

Dan