4k movies on my LG TV build-in player are significantly brighter and crispier than on the LibreELEC KODI on Raspberry Pi4

1st Official Post

    Check the picture settings of your TV, they can be adjusted separately for built-in players and each HDMI port - and there are separate picture settings for SDR and HDR.

    I've got a 55C8 here and when using the (usually recommended) ISF Expert Dark Room profile (set up with identical parameters for HDMI port and internal player) for SDR videos I don't see really a difference between RPi4 output and internal player.

    Edit: also make sure that you're not comparing HDR videos on the internal player with SDR from RPi4 (it doesn't support HDR output yet).

    so long,

    Hias

    • Official Post

    I had a similar issue on my RPi 3B+: The picture was darker than regular TV. After switching to a better PSU, the picture is as bright as TV. This is still a mystery to me, because HDMI is digital, and digital has no strong and weak signals. Probably it's about signals before HDMI.

    Quote from HiassofT

    Check the picture settings of your TV, they can be adjusted separately for built-in players and each HDMI port - and there are separate picture settings for SDR and HDR.

    That's the problem. The TV (LG) does not have anything special. The only option is "HDMI ULTRA HD Deep Color"

    LG Help Library: | LG Canada

    Is it relevant? I tried it ON and OFF, no effect.

    And there are no settigns for the internal TV player.

    And yes, both TV player and the Pi4 are playing the same content, when I compare.

    I noticed that this difference is huge for 4k movies and minot for the rest

    Quote from Da Flex

    I had a similar issue on my RPi 3B+: The picture was darker than regular TV. After switching to a better PSU, the picture is as bright as TV. This is still a mystery to me, because HDMI is digital, and digital has no strong and weak signals. Probably it's about signals before HDMI.

    I have a good one. 3A.

    Enabling "HDMI ULTRA HD Deep Color" is recommended as that'll make it possible to drive the display with 4kp60 (without it it'll be limited to 4kp30 on the RPi4). Other than that it doesn't make a difference for now.

    I meant checking the picture settings (i.e. where you can select picture mode, brightness, contrast etc).

    If the difference for non-4k videos is minor these settings are probably fine.

    I still suspect you are playing HDR 4k videos (eg HDR10, HLG or DolbyVision). In that case the difference will be indeed huge as RPi/Kodi can't currently output HDR. This means the maximum brightness, contrast etc will be far lower than if you play these natively on your TV.

    BTW: if you play HDR videos on your TV you may also notice a "DolbyVision" or similar popup and a change of available picture modes in the TV's settings.

    Basic support for HDR output has just landed in the Linux kernel and there are still quite some bits missing (in RPi video driver and Kodi) until HDR will be supported.

    so long,

    Hias