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TV Tuner Card - Pixelation

Last response: in Graphics & Displays
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April 23, 2009 12:46:12 AM

I have setup a HTPC. When watching digital TV through the HTPC, I get intermittent pixilation, which is quite frustrating.

My current rig setup is:

 Pentium 4 with 3GHz
 Intel 955X Chipset
 3 gig of DDR 2 RAM
 Inno3D/Nvidia 9500GT 1gig video card
 1T SATA hard drive
 Compro VideoMate Vista T750F
 Windows Vista 32-bit Ultimate and Windows 7 64-bit running in dual boot
 Display is a Sony Bravia 42” LCD connected through HDMI
 TV tuner card is connected direct to an external roof digital antenna

The problem seems to occur at various levels with all media center software tried. I have taken the following measures to try and resolve the issue but none seem to have identified the problem or fixed the problem:

 Monitored CPU load – not an issue, less than 30%. CPU load doesn’t seem to increase when the image pixlates.
 Tried Windows Media Center, DVB Viewer, Media Portal, Seasam TV and Compro software.
 Added additional 2 gig of DDR2 RAM.
 Changed codecs to NVIDIA PureVideo.
 Checked that the reception is okay. I get excellent reception when connecting the same antenna to a TV.
 Using a splitter and connecting two devices to the antenna because I read that the signal can be ‘too strong’.

Can anyone provide any guidance?

Thanks for your help.
Shamus

More about : tuner card pixelation

April 24, 2009 4:08:00 AM

I monitored my CPU load for a while last night and it seems to clock at 50% plus most of the time while I have digital tv running and no other programs. The load suddenly jumps to 100% every few minutes. I am thinking I might upgrade my CPU to a Pentium D.
April 24, 2009 7:26:57 AM

Its definatly your CPU that is causing the issue a P4 just isnt up to the amount of decoding needed for smooth digital viewing.
Upgrading to a dual of some sort will definatly help the issue, using one of teh ATI HD range of GPU's would be good also as they have hardware decoding built in.
I would get the CPU first as this will most probably be all you need to do, just keep the ATI card in mind in case you get any more issues.
Also be sure to check with your Motherboard manufacturer regarding compatability for duals or core 2 CPU's. A Bios update may be needed.

Mactronix
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April 24, 2009 4:59:46 PM

Since the CPU spike doesn't happen at the same time as the pixellation, I really don't think the CPU is the issue here. I've used different HDTV tuner cards with slower systems then yours and when decoding causes the CPU to spike, the display always skips rather than pixellates (granted, this could be due to software.) I think this is an important distinction because the only time I have ever seen pixellation is due to signal issues. Even the same signal being fed to two different pieces of hardware can have dramatic differences. I would really consider trying a different tuner card and/or clearing out the old drivers, codecs, and software before committing to new hardware, unless of course you're just looking for an excuse to upgrade anyway!
April 24, 2009 5:56:21 PM

If your pixelation is occurring EXACTLY when the CPU spikes to 100% then that' almost definitely.

However, if you get pixelation and you see your monitor isn't maxed out then it's NOT your CPU.

Since the antenna works with an HDTV, aside from checking your software is up to date I have no other ideas.

Product Requirements

* CPU
-1.7 GHz for TV viewing, DVD-quality recording
-2.6 GHz with SSE 2 support for HDTV
-3.0 GHz with SSE 2 for multiple PIP/POP TV watching
*  Memory: 512 MB ( 1GB recommended)
*  Available PCI 2.2 slot
*  Free disc space: 50MB minimum
*  CD drive for software installation
*  Sound card or on-board sound chip
*  Graphics Card or on-board graphics supports DirectX 9
*  ATX power
*  2-pin power switch connector from system case
*  OS: Windows XP SP2 / Vista x86/x64
*  Digital TV antenna

I still think your CPU is good enough. Again, monitoring the CPU usage (CTRL-ALT-DEL->Task Manager) will show this. Simply leave the Task Manager running overtop the screen with Digital TV decoding then glance down when you get pixels to see where your CPU is at.

It might even be Antivirus, Defrag or something else turning on which uses CPU power. You may be able schedule these better.
April 26, 2009 2:00:51 AM

I have a working Set-up of HD-Tuner in my PC.... I use with Media Center and or software that is provided by the vendor. In my case its hauppage-2250.


I can't comment on CPU requirement since I'm using a QUAD Core. When i look at my CPU utilization while watching its always single digits. For video cards i have tried 3870 512 , 4870 512, 8800GT OC 512, GTX 280 OC, & 4890 XOC...When i'm watching using media center my GPU utilization is ~ 7%. CPU utlization is less than 9%.

I have an old ATI Analog TV running on my OLD PC with ATI9800 PRO... That setup works well. HD TV is something else. It may need more horsepower.

When watching HD tv shows the most common cause of image distortion is related to reception. I have an AMPLIFIED ANTENNA specifically for HD TV reception. The GAIN is variable from 0 to 50DB. The Amplified antenna- is ~ $30.
April 26, 2009 5:41:29 AM

Thanks guys, I've used the excuse to upgrade to a Pentium D 925 3GHz, which is suitable for my motherboard. I'm also going to try reinstalling Window s and all drivers.
!