LibreELEC 11.0.3 - 10-bit HDR VP9 no video display / corrupted GUI on Alder Lake-N (N100) using HW decoding

Using LibreELEC 11.0.3 on a Alder Lake-N (N100) system. I've found 10bit (HDR?) VP9 HW decoding seems to be broken. HDR VP9 videos at 1080p, 1440p, UHD/4K don't play correctly. I did not try lower resolution versions. Audio plays, but nothing from the video is drawn on the screen and the GUI gets a bit corrupted. Nothing crashes and the video can be stopped and the GUI returns to normal. The HDR clips will play displaying an image with HW acceleration turned off for VP9.

I don't have a 10-bit non HDR VP9 video to test with (my understanding is that all YT non-HDR VP9 is 8-bit), so I don't know if it's 10-bit HDR specific or not. The standard non-HDR UHD/4K VP9 version plays fine.

The test videos are extracted from this Kodi sample library clip:

FWIW, the UHD/4K HDR AV1 version plays fine with HW acceleration. Also, if anyone is curious the N100 isn't able to play back the 8K/HDR AV1 version (to a 1080p screen) smoothly at the full 60FPS. It can only achieve ~33fps, but I suspect that's a lack of graphics processing capability in the Xe cores.

The UHD/4K HDR version info:

Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom (isom/iso2/mp41)
File size                                : 908 MiB
Duration                                 : 4 min 27 s
Overall bit rate mode                    : Variable
Overall bit rate                         : 28.5 Mb/s
Frame rate                               : 59.940 FPS
Writing application                      : Lavf60.10.100


Video
ID                                       : 1
Format                                   : vp09
HDR format                               : SMPTE ST 2086, HDR10 compatible
Codec ID                                 : vp09
Duration                                 : 4 min 27 s
Bit rate                                 : 28.3 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Variable
Frame rate                               : 59.940 FPS
Minimum frame rate                       : 58.824 FPS
Maximum frame rate                       : 62.500 FPS
Color space                              : YUV
Bits/(Pixel*Frame)                       : 0.057
Stream size                              : 903 MiB (99%)
Language                                 : English
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant
Mastering display color primaries        : R: x=0.677980 y=0.321980, G: x=0.245000 y=0.703000, B: x=0.137980 y=0.052000, White point: x=0.312700 y=0.328980
Mastering display luminance              : min: 0.0000 cd/m2, max: 1000 cd/m2
Maximum Content Light Level              : 1100 cd/m2
Maximum Frame-Average Light Level        : 180 cd/m2

Quote from chewitt

HDR support in Kodi is still a little WIP but I'd start investigation with the current 'Generic' nightly as this will have newer kernel and drivers and that may (or may not) help with recent-ish Intel hardware.

Okay, I will give the latest nightly a test later today and report back.

Quote from chewitt

HDR support in Kodi is still a little WIP but I'd start investigation with the current 'Generic' nightly as this will have newer kernel and drivers and that may (or may not) help with recent-ish Intel hardware.

The latest nightly does not fix it. Same issue.

http://ix.io/4Ec0

Seems like the decoder doesn't like it.

2023-08-21 17:41:57.503 T:972     debug <general>: CDVDVideoCodecFFmpeg - Updated codec: ff-vp9-vaapi
2023-08-21 17:41:57.515 T:972     error <general>: ffmpeg[0x55e6620]: [vp9] Failed to end picture decode issue: 18 (invalid parameter).
2023-08-21 17:41:57.516 T:972     error <general>: ffmpeg[0x55e6620]: [vp9] Not all references are available
2023-08-21 17:41:57.516 T:972      info <general>: Skipped 1 duplicate messages..
2023-08-21 17:41:57.516 T:972     error <general>: GetPicture - avcodec_receive_frame returned failure
2023-08-21 17:41:57.516 T:972     debug <general>: CVideoPlayerVideo - video decoder returned error
2023-08-21 17:41:57.516 T:972     error <general>: ffmpeg[0x55e6620]: [vp9] Not all references are available

Also discussing it here: RE: NUC recommendation for 4k HDR, hi-def audio

FWIW, I also confirmed the same behavior on a Whiskey Lake-U powered laptop.

Quote from smp

I can reproduce this on my Tiger Lake-U box. I opened a Kodi github issue.

Based on your discussion with Intel back in 2021 it looks like the issue is not the driver, but the way Kodi interfaces/interacts with the driver since the same iHD driver on the same LibreELEC system when accessed by FFMPEG can decode the 10-bit VP9 clips.

That latest nightly builds of LE 12 (after 08-29) can play 10-bit VP9 now.