Stuttering Live TV

[Ferral]

Hi all,
For the most part GBPVR is behaving well. I'm quite impressed. Only one more issue, unfortunatly it's quit a big one.

Live TV seems to play like a slideshow. Not all the time mind you, or else I'd be certain that I had codec issues or something. It seems to behave okay for a few mionutes, even up to half an hour or so. Playback is smooth and continuous. Then it starts to have a few hiccups which stedily gets worse untill it is playing at about 5 frames per second.

I'm running a PVR-150 on a Celeron 2.2G with only 256 of RAM. I know I need more memory 256 is pathetic, especially under XP. I've looked at herd disk thrashing and CPU load and neither seem excessive. The HD is almost at idle, probably because I'm not timeshifting, and the CPU is at about 60%.

Anybody have any suggestions what to try or where to start looking? I'm not entirely sure if it's lack of resources or codecs/drivers or what. It's a dedicated HTPC so it's only running GBPVR and HIP really, I've shutdown most other unused services as well.

Any suggestions appreciated.


Cheers.

[HtV]

Could it be a temperature-issue. You might want to check the temps from your cpu and videocard, or clean the fans and see if that helps

[Ferral]

Good point. The CPU seems fine, runnign at about 45c which is pretty tidy for a Cellery. The Vid card is a ATI 9200, passivly coooled and it seems to put out quit a bit of heat. When I was building the thing there were lot's of people that advocated the use of passivly cooled cards, probably because of the noise factor. Looking back now I can't see that a card fan actually produces much noise, indeed the DVD drive is the loudest thing in the box anyow. It might actually be inteesting to put a fan on it and see if anything changes.

I do have two temp probes on the case, I'll attach one to the heatsink on the card and see exactly what sort of temp it's reaching. Not enitrely accurate I know but it's good enough indicator.

Also being a SFF box the Vid card hasn't got much room to breathe so what heat the card is putting out isn't dissapating as well as it should. Improving the overall case airflow isn't a bad idea either really.

I do know that the heatsink on the card is too hot to touch..!! I have looked at it before, but it's never shown up any artifacts or problems so I assumed that it was operating okay.

But now you mention it, it quite possibly could be the cause of my issues.

Cheers for the reply.

[ricklous]

what are you using to feed your PC to your TV? my graphics chip is integrated and the chipset isnt fully directx9 compliant which gives me problems with the picture juddering after any osd elements are displayed. sometimes it cleans itself up, sometimes the judder stays and sometimes it gets worse. in this case i have to exit Live TV and enter it again. this is despite having plenty of headroom CPU/RAM/HD-wise. various deinterlacing settings affect the judder too. So id start by examining the chipset/graphics card on your system...

EDIT: sorry took ages over writing this, so didnt see HTVs comments! sounds like the likly cause if its only happening after half an hour...

[HtV]

Good luck, let us know the outcome.
Going to bed now, finished my bottle

[Ferral]

Hmmm.......

I've moved a few cards around and given the vid card a bit more room to breathe. I will hook up some extra fans to add more cooling but I'm not convinced it's my problem anymore.

The stuttering never occurs when playing a DVD or Divx movie. It only happens on live TV and some channels are worse than others.

I'm starting to think it could be aerial/reception related. I don't have the clearest picture on some channels, no snow but pic is somewhat distorted. If the problem was heat it I'm thinking it would be consistant over all operations, certainly over all TV channels. DVD and Divx playback would have to be affected as well.

Any thoughts?

[HtV]

Have tried changing your de-interlace settings?
Do you use FFDshow post processing.
I think I rember reading somewhere sometime, that one of the mentioned above would take more cpupower when you have a not so good signal:confused:

[csy]

Are you using the same video and audio decoders and renderers in your playback settings and DVD settings?

If not, what happens when you make the settings the same.

What is your Live-TV deinterlace mode (none, encoder-passthrough, deinterlace-filter)?

[Ferral]

Thanks guys, that seems to have fixed it.

I changed the deinterlace and ffdshow settings and now everything is smooth.

I'm not sure which deinterlace I've enabled now, I'll have to look and take note in case I get the urge to play with it and stuff it up again...8)

cheers...