Occasional pixelation on Freeview

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Seasport

50 posts

Geek

#29882 22-Jan-2009 10:22

Ok so I have Mediaportal V1 running well and have most of my teething problems sorted. I get a great picture most of the time. However, I continue to get intermittent problems with pixelation or blockiness in the picture. What I mean by this is that I get a transient pixelation effect in parts of the picture (seems to mostly around edges). This only happens sometimes - like I can be watching a program for an hour and it is perfect and then it starts happening every 10-20 seconds or so. This happens in both Mediaportal and DVB Viewer so is not application related.

I have read a few older posts where people have put this problem down to the codec or signal levels. If it was codec related you would think it would happen all the time. Also I think I have good signal strength (line of sight to transmitter and good quality cabling). Has anyone been able to verify the cause of this problem?

3GHz P4
Vista 32
1GB RAM
8500GT with H.264 h/w acceleration
Hauppauge HVR3000
Mediaportal V1.0
Cyberlink PowerDVD 8 codec
EVR

mthand

148 posts

Master Geek

#191402 22-Jan-2009 22:50

From memory, when I was looking around for information/confirmation of this issue, I read that someone with a set-top box had this issue too. I have to say, I was pretty disappointed with it at the time, but I accept the fact that this is something that is perhaps out of mine, or anyone's, control.

I only notice it very occasionally now, and since I don't have line of sight to waiatarua, it only confirms to me that it is an atmospheric signal disruption, or some kind of interference.

Perhaps the only thing I would be willing to do now if it really bothered me would be to get up on the roof and play with the aerial. But it's not that big of an issue, I'm a little scared of heights and it certainly wouldn't give me any excuses when it comes to not cleaning out the gutters!

Seasport

50 posts

Geek

#191636 23-Jan-2009 17:48

Thanks. I think you're right. It must be related to signal strength or perhaps interference of some sort. The picture is just fine most of the time but then once this starts happening, it happens frequently and it is very annoying.

I guess I need to check whether this happens when I am watching recorded TV. (I don't think it does). That will give me an idea of whether it is signal related.

What's the best way to measure the signal strength?

mthand

148 posts

Master Geek

#191669 23-Jan-2009 21:32

Mediaportal has some signal strength and signal quality bars under tv server config/manual control, and also has some information in the logs when the tuner cards are "engaged" (for want of a better word). Also, when viewing a program in Mediaportal, i can press the "i" button (hauppauge remote) to bring up a menu. At the bottom of the menu, it will have something like "tuning detail", which, when selected, will then bring up a box with all sorts of information about the channel you're viewing.

When this starts happening again, hit the record button on what you're watching, and compare the spots during the show that are distorted, then replay and you should see the same distortion at the same spot(s). Just like VHS, it will record any distortion, blockiness, green screen and, worst of all, commercials that are received by the capture card.

Added to that, the recorded content also gets corrupted, either by the PVR or some errors on the drive and exhibits a kind of fast play or skipping effect on playback.Only for a few seconds though.

ajst2duk

170 posts

Master Geek

#191729 24-Jan-2009 08:19

Hey I'm glad it's not just me. When it happens on our machine (GBPVR Vista Hauppauge Nvidia 9600gt) we can often fix it by restarting the PVR during an ad break. I often suspect it may be the Hauppauge 2200 tuner as I also have 2 USB tuners. Anyway, my other half and kids are pretty critical of it when it does happen - you guys probably know the looks - it would be brilliant if someone has actually isolated the issue

Seasport

50 posts

Geek

#192105 26-Jan-2009 12:21

Thanks for the tips. I'll have a play around with Mediaportal. I wonder if it is a Happauge thing. The thing is that it works fine most of the time and just seems to start after you have been watching for an hour or so. So maybe signal related or maybe heat related??

Yeah can identify with the looks from the other half! Mine prefers MySky HD even though the picture is crap compared to Freeview HD on most channels. Sort of smarts when you've spent hours getting this stuff working & tweaking etc.

Oh well I guess a box with an on/off button is always going to win!