[devilledham]

My HTPC is on Ubuntu 18.04.6 LSB with Kodi 17.6, using KDE. It's a Xeon X5677, and I have a gtx1050 running the latest Nvidia drivers, 515.57.

It plays almost everything I throw at it perfectly, except for 4k60 HEVC videos from my phone, which playback very choppy.

I have tried putting a gtx1060 that I have spare into it, but unfortunately it had the same result as with the gtx1050.

I imagine that it's not doing hardware decode for those particular videos for some reason. I believe that a gtx1050 should be able to hardware decode those videos.

I'm pretty green when it comes to the details on how GPU drivers in linux and how kodi works.

Does anyone have any ideas or links on how I can resolve this, or how exactly to troubleshoot it?

[Klojum]

I've been using Ubuntu Linux on various PC over the last decade, and one thing I noticed that graphics drivers are still handled relatively poorly in Linux compared to Windows. This has involved Nvidia GTX 950/1030 cards and currently Intel igpus. For some reason, Linux still cannot keep up speedwise on desktop graphics and things like Youtube videos in a web browser.

One example: with my low-power J5005 Intel UHD605 box, in Windows 11, a Youtube video in Firefox will do upto 4K60 in VP9. That same video in Ubuntu Linux 21.10 (my current daily driver) and Firefox on the same box, is acceptably shown upto 1440p30. Above that, stutters will come in. Similar experiences came with the Nvidia setups before that. I'm pretty sure the same will happen in HEVC videos. So are your phone videos 10bit videos?

So yeah, Windows gives a smoother 2D video experience. There is that. On top of that, Nvidia in Linux using VAAPI only supports 8bit video. I can do upto 8K video in LibreELEC that way. There are the NVENC drivers for Nvidia, but I don't know if they are available for Ubuntu 18.x already. You are using KDE and probably a more powerful CPU/machine than I do, so your mileage may still vary. I still prefer Ubuntu for its overall user-friendliness (imo), but it does come at a price.

[devilledham]

Here's the mediainfo output for one of the videos. I was surprised because I thought they were 10 bit but actually they're only 8 bit.
It's sad to me that my phone can play these smoothly and the full HTPC with a GTX1060 can't!! Nvidia needs to get their shit together on Linux. The current GPU in my desktop is AMD now because I value Linux support.

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : [email protected]@main
Codec ID                                 : hvc1
Codec ID/Info                            : High Efficiency Video Coding
Duration                                 : 1 min 22 s
Bit rate                                 : 40.4 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Variable
Frame rate                               : 60.000 FPS
Minimum frame rate                       : 30.000 FPS
Maximum frame rate                       : 60.362 FPS
Real frame rate                          : 60.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Bits/(Pixel*Frame)                       : 0.081
Stream size                              : 395 MiB (99%)
Title                                    : VideoHandle
Language                                 : English
Encoded date                             : UTC 2022-04-27 01:03:46
Tagged date                              : UTC 2022-04-27 01:03:46
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
transfer_characteristics_Original        : BT.601
Matrix coefficients                      : BT.709
Codec configuration box                  : hvcC