[oldtvwatcher]

This is something that I've been meaning to ask for a while. It may affect all versions of XBMC but since I only run the Linux version (Frodo under Ubuntu) I will try asking here first, in case it's a Linux-specific issue.

Has anyone else noticed that video seems to be less sharp when viewed in XBMC as opposed to when viewed on other software? This is particularly noticeable when playing back TV shows that have been recorded. As an example, if I record a local newscast on a MythTV backend, and play it back through XBMC, the picture seems to me to be a bit degraded, as if it's scaling down to lower resolution. If I play the same program in the MythTV frontend, it's noticeably sharper. This is on a 42" LCD TV - it might not be as noticeable with a smaller screen. This is especially noticeable with live shots from a studio but it's also at least somewhat visible in regular HD TV shows.

The TV is set so there is no overscan, and I am not letting XBMC resize the picture or anything like that, so I can't see any reason I should be losing sharpness, but it appears that's exactly what's happening. Has anyone else noticed this? Is there any setting that can be changed that would improve the sharpness of the picture?

[ulibuck]

I had the exact same issue and could resolve it by setting "Adjust display refresh rate to match video" in the Video/Playback Settings

My recorded TV shows and Live TV are now displayed at their 50 Hz rate and not at the 60 Hz rate which my HTPC normally displays.

When exiting XBMC to the desktop environment the 50 Hz rate is maintained, which makes the display there a bit blurry. Changing the refresh rate back to 60 Hz in the Nvidia driver settings gets the desktop display back to its best sharpness.

[oldtvwatcher]

I had the exact same issue and could resolve it by setting "Adjust display refresh rate to match video" in the Video/Playback Settings

My recorded TV shows and Live TV are now displayed at their 50 Hz rate and not at the 60 Hz rate which my HTPC normally displays.

When exiting XBMC to the desktop environment the 50 Hz rate is maintained, which makes the display there a bit blurry. Changing the refresh rate back to 60 Hz in the Nvidia driver settings gets the desktop display back to its best sharpness.

Thank you. Do you recommend setting it to "On start/stop" or to "Always"?

Also, do you turn on the "Pause during refresh rate change" setting?

[ulibuck]

The settings I am using are

"On start/stop"

"Pause during refresh rate change" --> off

[nickr]

May be to do with deinterlacing.

Those mythtv guys do have the TV playback stuff pretty sorted, given that TV is myth's main rasion d'etre.

[oldtvwatcher]

The settings I am using are

"On start/stop"

"Pause during refresh rate change" --> off

That actually does appear to improve the picture quality - now I don't see any discernable difference between XBMC and the MythTV frontend. Thanks!

[noggin]

If you are watching native interlaced content - then you need to ensure that you have de-interlacing set to Auto, and a decent de-interlacing algorithm appropriate to your hardware (and build) enabled as well.

For recent OpenElec nightlies running on Intel for instance, I use VAAPI decoding but have software filters enabled to allow me to select "Deinterlace" as the deinterlacing algorithm, which is a good quality software Yadif 2x deinterlace. On an nVidia build I use Temporal/Spatial.

Because most of my video content is 50Hz, I have XBMC configured to run at 1920x1080/50Hz as the default, and then with Adjust display refresh rate to match video enabled it flips to 24/60Hz when I play that content.