4K, deinterlacing, various picture quality problems



At my wits’ end trying to get this to work, and hoping someone might be able to help.

Have a HTPC setup running Win11 connected to a 4K Philips TV, bought new, which has never displayed a 4K signal. Sent off for repair within warranty only to be told nothing wrong. Technician who collected the set suspected main board failure due to heavy posterising on multiple sources, including native streaming apps. I don’t compress any of my media stored externally, so can’t explain it. Have done my best to ensure the Kodi YouTube app receives either FHD or 4K, but even IMAX trailers look compressed. Xbox One goes blank when I try to enable 4K. Bought a replacement 4K cable, but no change.

Windows display properties are set to 3840 x 2160 50hz. Advanced Display Settings currently reads: 8-bit depth, YCbCr444, SDR, HDR Certification Dolby Vision. Just performed complete reinstall/repair AMD chipset drivers with no discernible difference. When HDR is enabled, anything remotely ‘light’ on screen is glaring and uncomfortable to look at. Meanwhile, Kodi GUI is dull and desaturated. Content plays fine either way, but I’d be amazed if actually being upscaled to 4K – 1080p seems to be the limit. Tried the Windows HDR tool without success.

Something else I noticed – media seems to play best if DXVA2 is not enabled. This is acceptable for modern content, but anything SD/interlaced doesn’t look right (or, certainly doesn’t play with expected smooth motion) unless DXVA2 is re-enabled.

Scrubbing interlaced media with DXVA2 enabled results in audio running smoothly, but massive visual disruption until it ‘catches up.’

Very grateful for any advice, please.