Pixelation During Live TV, but Recording Fine

[drw6]

I'm using WMC with an HDHomeRun Prime. When I come back to it after an extended period of time (like, the next day), the video will be completely pixelated (grey blocks, no visible picture) with normal audio. Switching channels will not correct the problem; however, tapping record and switching channels (i.e. forcing it to switch tuners) will clear up the problem, as will briefly playing a recorded show and then returning to live tv. Interestingly, tapping record without switching channels does not fix the problem, but subsequently viewing the recording of the pixelating show will display the picture normally (i.e. the problem is not the tuner nor the connection to the tuner). The problem never affects recordings or recording playback, only Live TV, so I don't think that it's a codec or display driver issue.

I've never witnessed the issue actually occur. That is, I've never had a clear picture that I was watching suddenly start exhibiting pixelation while watching it.

Since the problem occurs when the HTPC sits overnight, I tried disabling the optimization settings in WMC (i.e. preventing the overnight service restart), in case that was freaking it out, with no effect. Upgrading to Windows 8.1 didn't fix the issue, but I don't know if they made any changes to WMC in the update, so perhaps there's no reason that it should have.

The HTPC is running on a 3.3 GHz i3 with 8GB of RAM and both the computer and HDHomeRun Prime are directly connected to a Gigabit router via cable, so wireless isn't the issue. OS is installed on an SSD. Recoding drive is a dedicated 2TB SATA3.

Google searching has turned up nothing, as all the usual causes of pixelation appear normal during the issue. If I query the tuner during the problem, it reports a clear, strong signal. CPU, network I/O, and disk I/O appear normal during the issue.

Anyone seen this problem before?

[Scallica]

What firmware are you running on the HDHR?

When the issue occurs, connect to the tuner's web page. What is the signal strength and quality?

What router are you using? You should really be using a gigabit switch to connect the PC and the HDHR.

[drw6]

Firmware is 20130328

Can't say for certain what the signal strength is during the issue, as the mere act of un-maximizing WMC to check clears up the picture. At that point, both are in the high 80s (at least currently; I've seen them in the high 90s).

Router/switch is a Motorola SURFBoard SBG6580, so it is a gigabit connection.

I don't think that the problem is with the HDHR connection. If it was, it wouldn't record the pixelated show correctly. Also, if that we the cause, I would expected, at least once, for it to have affected a recorded show, rather than only affecting live TV after WMC has sat for a while. I don't see any evidence that this is anything other than a display issue in WMC.

[Scallica]

What video card and driver version are you using?

[drw6]

Intel HD Graphics 4000 (i.e. the on-chip for an i3).

Driver version is 10.18.10.3316, dated 10/1/2013; although I saw the same behavior with previous versions.

[Scallica]

I think the latest driver is 15.33.5.64.3316.

Have you tried an add-on video card as a test?

[STC]

Any power management getting in the way?

[drw6]

I've turned off every power management setting that I can. Doesn't help.

Haven't tried a separate video card, 'cause I don't have one (my other machine is a laptop). I don't think that it's the video card, though, because during the issue all other features (on screen menus, etc.) appear normally. True, it's possible that the card/driver could still be at fault, but the odds are sufficiently low that I'm not going to buy a card just to rule it out.

[Scallica]

I would test different driver versions. You can probably find a decent used video card on eBay for not much.

[homerholmes]

I too have the same issue where if I record a program I can view it fine, but if I try watching a HD live program I get pixelization.
I have other computers but none with exactly the same hardware. The other computers don't seem to have this issue.

If I watch a show using the older hdhomerun viewer (not the new one) it works fine as well.

I am currently using a EVGA Nvidia Gt610 2 gig video card with the latest drivers. I have 8 gig of ddr2 ram. My processor is an intel core duo running at 3 ghz.
and I have a ton of space on my defragged hard drive. My built in NIC supports 1gig byte rates.

I have tried swapping the video card, and the motherboard with no change to the problem.

The items left to swap are the memory, hard drive and last the cpu.

[poit57]

I don't see this issue under in the same situations as the original post, but the symptoms are similar. I usually notice the gray screen/pixelation when I pause TV to take a phone call for several minutes. It doesn't matter if it is live or recorded TV. To resolve the issue for a recording, I can either stop then resume the recording or switch to live TV before resuming. To resolve the issue for live TV, I can either switch to a different channel or stop the live TV and restart it. That is kind of frustrating when I'm in the middle of watching something that I hadn't set to record.

I think this is an issue with the graphics drivers. I use Intel HD 4000 graphics and try my best to keep my drivers up to date.