Libreelec on Intel NUC i3-6100U video levels and stuttering

  • Hi,

    I am new to libreelec and Kodi. I've installed it to a new Intel NUC i3-6100U and I have several questions / problems that I hope I can find an answer here.

    1. The first problem is with video levels. As described in the Kodi wiki, the best setting for RGB colors is Limited - Full - Limited. I have setup my TV and Kodi to use limited RGB 16:235 and the GPU I have set it to full using xrandr. The problem is that when I reboot, the GPU switches back to 16:235 Pass-through. In order to solve that I have created a file in /storage/.config called autostart.sh and I chmoded it +x and when I launch it ./autostart.sh it works fine.

    In Openelec after reboot, this file is launched and the levels are Full, but in libreelec it does not work.


    Where should I put this file in order for libreelec to launch it at boot?

    2. Still concerning video levels, I have searched online but could not find an answer. I see in xrandr that the default setting is 16:235 Limited Pass-through. What is the difference between limited pass-through and limited? Does it mean it does not touch the video? I ask this, because, frankly I see no difference on my TV between Limited Pass-through and Full. I suppose that both settings leave the video untouched at GPU level, but I would like to be sure, then I would not need to set it to full anymore.

    3. I have also a Popcorn Hour A310 that works like a charm. The image the popcorn generates on the same TV with the same settings is better than my NUC with Kodi. As I have checked to see the differences, I see only one difference. Popcorn uses YCBYCR instead of RGB. The colors are warmer, more pronounced. I cannot seem to find a way to put my NUC in YCBYR. I only have RGB

    4. The other problem concerns stuttering. I have installed libreelec with Kodi 17.4 and I have no stutter, but after the last update to Kodi 17.5 I get stutter on 23.976 1080p movies, using the same settings as in 17.4.

    I use in Player - Switch refresh rate always and VAAPI hardware acceleration. Anyway, I have tested with or without acceleration, without is worse.

    So I have reinstalled 17.4, for the time being it's ok.

    5. I have a last question, less important, but still. With Popcorn when I play a 3d file, the TV detects automatically that it's a 3D and switches to 3D according to the encoding of the file (side by side or top to bottom). With Kodi, it just plays my file in 2 D showing the 2 images either side by side or top to bottom. I was wondering if there's something I can do to have the same behaviour as my Popcorn.

    Thank you in advance for your help,

    Adrian

  • 1) LibreELEC also does have the autostart.sh file, although I'm not sure why you are limiting the video coloring output to begin with.

    2) I'm not the top audio guru here, others will need to reply on that.

    3) Popcorn video may be 'warmer', perhaps its settings are boosted beyond the normal parameters.

    4) Stuttering can have many causes. Are you trying to play a HEVC/h.265 video, 10bit, or something with a ridiculous high bitrate perhaps? Provide the kodi.log file so we can see more technical info and data.

    5) It's an Intel thing. A Raspberry Pi will auto-change 3D settings on the TV, an Intel device/gpu will not. You will have to manually change your 3D settings in your TV. Call it a 1st World Problem. :)

  • 1) LibreELEC also does have the autostart.sh file, although I'm not sure why you are limiting the video coloring output to begin with.

    2) I'm not the top audio guru here, others will need to reply on that.

    3) Popcorn video may be 'warmer', perhaps its settings are boosted beyond the normal parameters.

    4) Stuttering can have many causes. Are you trying to play a HEVC/h.265 video, 10bit, or something with a ridiculous high bitrate perhaps? Provide the kodi.log file so we can see more technical info and data.

    5) It's an Intel thing. A Raspberry Pi will auto-change 3D settings on the TV, an Intel device/gpu will not. You will have to manually change your 3D settings in your TV. Call it a 1st World Problem. :)

    Hi, thank you for your reply.


    Could you please tell me the location of the autostart.sh file in libreelec?

    Thank you,


    Adrian

  • Hi, well that's the problem, it does not work. As I said in my first post, I have created it in /storage/.config and still it does not work. Here is the contents of my autostart.sh :

    Bash
    #!/bin/sh
    xrandr --output HDMI1 --set "Broadcast RGB" "Full"

    As you said, I want it in full and not limited, that's what I am trying to do, but when I reboot GBU goes back to 16:235 Limited Pass-through. By the way, in this case, pass-through refers to video, not audio. I have no problem with the audio pass-through.

    Can you see anything in my file that is wrong ? Why is it not launched at boot?

    As I said in my first post, I have installed Openelec, just for test purposes, and the same file in the same folder gets launched at boot, so there is really something with libreelec that it does not like my file.

    I have also chmod-ed it correctly :

    Code
    chmod +x autostart.sh

    Do you have any idea as to why it's not getting launched at boot?

    The code is correct, or I think it is because if I launch it from terminal ./autostart.sh the GPU switches to Full.

    Thank you,


    Adrian