RPi4 testbuild with HDR support

    Quote from noggin

    I guess the following is how the preferences work ?

    2160p30 and below : RGB 12-bit, YCbCr 4:2:2 12-bit, RGB 10-bit, RGB 8-bit

    2160p50 and above : YCbCr 4:2:2 12-bit, RGB 8-bit.

    (There are no 4:4:4/RGB modes at >8 bit supported in 2160p50 and above in HDMI 2.0, and 4:2:2 YCbCr is supported at 12-bit only)

    4:2:2 12-bit YCbCr at 2160p50/60 is often only supported by some (not all) HDMI inputs on some TVs (like my Sony XF9005 - which won't support this format on HDMI 1 and 4, only 2 and 3) and has to be enabled in TV menus. Similarly my Denon AVR has to have support for 4:2:2 12-bit enabled in its menus too. It's often called 'Enhanced HDMI' or similar. It also requires higher performance HDMI cables to work reliably as the bandwidth is pushing the limits of the HDMI 2.0a spec.

    if hdmi_enable_4kp60=1 then 2160p30 will use RGB12-bit (and scrambling due to increased clock). If it's not set you'll get YCC422 (no scrambling). Assuming edid allows.

    Correct for 2160p50 and above.

    What are the recommended Kodi settings to play back 4K HDR content?

    1) setting resolution to maximum supported, with limit gui to 1080 ? i thought this controlled the gui resolution, but then the limit gui option is a bit confusing.

    -or-

    2) setting adjust display refresh rate to on start/stop? this seems to work, however 24hz refresh rate playback was a bit weird (doesn't seem smooth, hard to describe)

    Samsung TV is reporting 3840x2160@24Hz, Input Signal Plus, HDR, UHD.

    Also, I don't see any 4Kp60 resolutions in Kodi, is that working or am I missing something?

    Edit:

    1. Option #2 seems fine, paired with whitelisting 50-60hz refresh rates and using the pull up/double options. I only whitelisted 1080 & 2160 resolutions, leaving Kodi to upscale to 1080.

    2. Still can't explain why Kodi didn't see 60hz refresh rates at 4K, but I restarted Kodi and they are showing up now.

    Edited once, last by frakkin64 (December 18, 2021 at 10:49 AM).

    FYI: the 10/12-bit video output patches have been merged into the master branch and will be included in the next nightly build (20211219) - please use those for testing when they are available as they include other fixes as well (eg for deinterlace).

    If you prefer to stay on LE10 here's a first LE10 testbuild with 10/12bit video output and deinterlace patches (plus lots of other fixes, too):

    https://www.horus.com/~hias/tmp/libreelec/LibreELEC-RPi4.arm-10.0-devel-20211218214422-480810e.tar

    It would be great to get some feedback on the LE10 testbuild as well, initial testing here looked good, but we'd like to have some more positive confirmation that things work as expected before adding the backport patches to official LE10 releases.

    so long,

    Hias

    chewitt Awesome guide, thanks. I ended up with the same settings, the only thing is 4Kp24 looked weird as I mentioned like it was sort of slow, hard to describe it. Whitelisting the 50-60hz ranges only and letting Kodi double up the frames seemed to smooth it out. I appreciate the notation you made about the HDMI cable, CanaKit claims it supports 4Kp60 and it seems to be working now, but I'll keep an eye out for problems there.

    So far I am using it on LE 10, with 5.15 kernel from LE11, and everything seems to work fine.

    This is great work from LibreELEC & Raspberry Pi teams. Thank you!

    Quote from HiassofT

    It would be great to get some feedback on the LE10 testbuild as well, initial testing here looked good, but we'd like to have some more positive confirmation that things work as expected before adding the backport patches to official LE10 releases.

    Installed on my spare machine, so far so good. Have flicked through a few channels with 1080i content and it looks as good as my main Intel HTPC. TV isn't 4K so haven't had a chance to try that or HDR etc yet.

    I have a raspberry pi4 running on LibreELEC 10.0.0 running with the official Raspberry PI4 HDMI Mini adapter & official RPI4 PSU type-c.

    My television is a TCL 50S431 which supports HDR and HDMI 2.0.

    When watching the Witcher (S2E2) via my own file, it shows washed out colors (Netflix symbol is orange).

    However, when I watch on Netflix, the HDR symbol of my television is actuated and the colors are vibrant and bright (Netflix symbol is red and looks fine)

    Any ideas? chewitt, HiassofT, you guys seem like geniuses, please help, the mindboggling complexity of HDR awaits.

    Thank you for your wonderful work on this project, despite my current issue, I remain quite impressed by this project.

    -Shawn / Glyph

    Edited 2 times, last by glyph (December 19, 2021 at 5:18 AM).

    Quote from HiassofT

    FYI: the 10/12-bit video output patches have been merged into the master branch and will be included in the next nightly build (20211219) - please use those for testing when they are available as they include other fixes as well (eg for deinterlace).

    Are nightlies here : https://test.libreelec.tv

    If so the Pi4 build seem to stop on the 18th Dec? Others are there for the 20th and 19th for other platforms. Does it take a while for Pi 4 nightlies to build?

    Quote from HiassofT

    If you prefer to stay on LE10 here's a first LE10 testbuild with 10/12bit video output and deinterlace patches (plus lots of other fixes, too):

    https://www.horus.com/~hias/tmp/libr…422-480810e.tar

    It would be great to get some feedback on the LE10 testbuild as well, initial testing here looked good, but we'd like to have some more positive confirmation that things work as expected before adding the backport patches to official LE10 releases.

    I Just updated from 10.0.1 to this version, and it's great! I had many problems/bugs with the 10.0.1 that I considered switching back to x86. But it's the first day and so far so good @4K60 and HDR. x264 also works now. HDR seems a lot better also. Thanks for the release.

    I have pi4 4GB > Marantz AVR > Samsung Qled.