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:

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    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:

    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.

    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.

    Code
    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

    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.