HTPC TV Card - what causes this defect?

It's happened on a couple of recordings, a patch of picture breakup accompanied by sound distortion, just for a few frames, and only 1 or 2 per hour. Full image:



I've been doing other things on the PC during the recording, and wondered if other processor demands could cause a stutter. Hauppauge Nova-T PCI card.

 

thats quite poss, as what amout of cpu usage does the card take whilst playing live TV and also recording it?

 

That's weird, it's usually 20-30% for either (Sempron 2600+, stock), but just tried and view-only was bouncing up to 100%, went down when I started recording (2/3 along) and stayed down after going back to view-only.

 

hmm.....need some time on this one, it maydo with its tuner but with all the hauppaggue stuff ive had allways had high or stuttering effects.

 

If you have been doing heavy stuff that uses your hard drive and cpu it is possibly that but if you havent then it's probably interference or signal problems(or a combo of both), it could be you PSU, your pc's fans or a light switch in the house or even your central heating switching on. Even a bus or a moped going pass your home can effect dvb-t signals.
I bet you see it more on ITV channels or five? why it's because these are QAM64 channels which are more likely to break up, also weather can play it's part in effecting signals. When the analogue signal is turned off they will increase the power of the broadcast signal for dvb-t which should help with some signal problems.
Finally some onboard SATA controllers (this might explain if it doesn't occur when watching but occurs when recording) and HT and cool n quiet can also effect it on occassions, so good luck fixing it. If you have a freeview set top box this is less likely to be effected due to less EMF from the components/fans inside the box and possibly psu being outside the box (although it still occurs), just before anyone says but my set top box doesn't suffer and it's on the same aerial.

To lower your cpu usage make the hauppauge software (if your using it) use vmr instead of overlay.

 

Just surfing, but my browser cache is on the same slave drive as the TV stuff store folder, I'll try moving it back to the other drive.

STB and card share an aerial through a hard-wired resistive splitter (masthead type), no problems with the STB and I can see the transmitter from ground level, good signal.

I'm using the ShowShifter software recording to mpeg2, not seen VMR/Overlay options in the menus. However, I can give the program higher priority, so I'll give that a try when recording good stuff.

One search result,

and there's a reg hack to enable VMR on the same page.

 

is that a digital card? as in DVB....
it's most probs a loss in signal if it is

 

yea we used to get this on our tv when using crappy indoor aerial, got a proper roof mounted aerial and it went away

 

It does look like signal breakup to me, we get it on Sky when somebody walks in front of the dish, or in really bad weather.

 

walks infront of the dish?

people walk on your roof fairly oftent then?

 

My house is Grade 2 Listed, so we can't add anything to the roof. It's on a pole by the side of the house.