HDTV gives stuttering picture

[thrilled]

Hi everyone,

Been trying a few other forums without a single response so now my hope lies here

When I am playing HDTV then I experience stuttering and this is really annoying. It's only when I am playing HDTV Live since when I am playin a 1080p 46Mbit movie from HDD then it works perfectly. So I think it's a configuration/codec issue here.

I have a 52" Sony KDL-W4500 Full HD TV and using the resolution 1920x1080 on my HTPC to the TV.

I am using:

Windows Vista Sp1
Hauppauge WinTV Nova S2 HD
Mediaportal 1 RC3
CoreAVC Codec for HDTV
Nvidia Purevision codec for SDTV
Nvidia 7800 GTX
4GB Memory
E5200 2,5GHz @ 3,6Ghz

I am open to all kinds of ideas which may improve my picture quality and most of all getting rid of the stuttering

Sincerely!

/Mikael

[jagabo]

If the stuttering is very fast and consistent you may have the field order wrong in the deinterlacer. People often call this strobing or flickering.

If it is more random you might have a decoding problem. Are you using CoreAVC Pro or the standard version? The standard version is only single threaded. The pro version is less likely to run out of CPU power on a dual (or more) core CPUs because it's multithreaded.

[thrilled]

Hi Jagabo,

Thanks for replying. Much appreciated!

I am using the CoreAVC Pro version. Currently I have the deinterlace setting set to hardware (I changed that yesterday, and have not been able to test HDTV yet after the change).

Beside that I am not sure what settings is to be used with CoreAVC Pro.

Best Regards!

/Thrilled

[jagabo]

There are two field orders in interlaced video -- top field first, and bottom field first. Some programs refer to them by other names, even/odd, A/B, 1/2, etc. Basically, an interlaced frame consists of two half images called fields. These fields are meant to be viewed one at a time. On an interlaced display there is no problem, they are designed to view one field at a time. But progressive displays have to deinterlace and produce two full pictures from the two half pictures. And they need to display them in the correct order. When displayed in the wrong order you get a very fast jerkiness whenever there is motion.

If the hardware deinterlacing setting in CoreAVC is causing problems try switching to BOB or Single Field.

[thrilled]

Will come back with the results from my tests tonight.

You don't happen to have any good advice of what codecs gives the best picture quality in standard resolutions (by that I mean material which isn't HD)

Best Regards!

/Thrilled

[thrilled]

Ok some testings made.... tried both hardware and bob deinterlace with CoreAVC and BOB seems best. However still having "stuttering" on some channels.. But another (VoomHD) looks just perfect with very minimal stuttering.

However when I am looking with my HDTV box that I bought along with the subscription of Canal Digital then I can see all the HD channels without and stuttering. So there are something with the my config/settings. Damn I wish I could find out

/Thrilled

[thrilled]

This is indeed a strange problem.. I hope you have some ideas about this

/Thrilled

[jagabo]

From the Display Properties dialog select the Settings tab then press the Advanced button. At the next dialog select the Troubleshoot tab. Make sure Hardware acceleration is turned all the way up and Write Combining is enabled:



You'll have to reboot for the settings to fully apply.

[thrilled]

Will try when I am back home, once again thanks for your most precious help!

/Thrilled

[thrilled]

Hi again,

Yesterday I was checking my HTPC and for some reason these settings are "greyed out" and a text saying the display driver does not support these options (when I want to click on the advanced settings under Troubleshooting).

Strange I though and made sure that I had the latest drivers installed which I had.

Any ideas what to do?

Best Regards!

/Thrilled

[johns0]

I'm on vista 64 sp1 with a geforce 8800gt and my display is grayed out as well for advanced settings,just a vista issue,also the stuttering might be your cpu cant keep up with the data output of playing HDTV Live.

[jagabo]

You may have to run as administrator to change those settings.

[thrilled]

I have turned off the UAC so isn't a problem with administrator rights but more a vista issue as johns0 said. Also it's not a CPU issue since I can play the HD files perfectly if I am running them from the harddisk. Only experience this with live tv it seems.

Also noticed that PowerDVD's codec is much worse then the Nvidia Purevideo codec however I cannot find a way to set which codec I want to use in PowerDVD8

Sincerely!

/Thrilled

[jagabo]

My guess is PowerDVD will only use it's own internal codecs. You might check to see if it supports different output options. Video Overlay, VMR7, VMR9, etc.