Posts by smp

I see no reason why the number of EUs would affect the video playback. It can only make a difference when rendering Kodi GUI.

Quote from PKOneTwo

Asking because in this test (Intel NUC7CJYH im Test mit LibreELEC und unter Windows 10) which is running on Kodi in WIndows, the test file did run perfectly on the J5005, but not on the 4005

That same test also says:

Quote

Under LibreELEC all of our test files run smoothly

Quote from TaceN

I need to get hold of version 8.2.5 for Le Potato.

There is no 8.2.5 for Le Potato.

And yes, 9.0.2 is buggy and unusable on Le Potato - live TV issues and also file transfer issues due to this buggy patch.

I figured out how to force YCbCr 4:4:4 instead of RGB:

diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 93ac0f2..6336b4b 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2418,7 +2418,7 @@ int intel_hdmi_compute_config(struct intel_encoder *encoder,
     if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
         return -EINVAL;
 
-    pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
+    pipe_config->output_format = INTEL_OUTPUT_FORMAT_YCBCR444;
     pipe_config->has_hdmi_sink = !force_dvi && intel_hdmi->has_hdmi_sink;
 
     if (pipe_config->has_hdmi_sink)

Unfortunately this did not fix the Samsung issue. 4K YCbCr 4:4:4 8-bit works fine but "no signal" with 12-bit.

Quote from noggin

That's not correct.

Yeah, it is indeed in the specs. But still the only useful 4:2:0 modes are 8-bit (for displays that don't support > 9Gbps link speed).

Quote from teeedub

Since GLK does not support 10bit modes, does that mean the signal being sent was 12bit?

No, the signal was 8-bit. Despite the popular opinion HDR does not really require 10/12 bit and the TV will switch to HDR/ST.2084 mode when HDR metadata is present.

Quote from teeedub

I wasnt sure how to get more info from the j4105 about what display mode is being used.

Enable DRM debug logging in syslinux.cfg:

drm.debug=0x1e log_buf_len=5M

Then

journalctl -f | grep -E 'color|bpc'

4K 4:2:0 with Deep color is not a part of HDMI spec. It should always be 8-bit.

No idea how to force YCbCr 4:4:4. Intel driver knows what's best for you and use RGB.

Quote from teeedub

From memory, to get it working I booted the j4105 with the TV in UHD mode, got the available UHD modelines via SSH, and then added them via a boot script and xrandr.

That will not give you the 12-bit Deep color modes in 4K (10-bit is not supported by GLK hardware). There is no difference how you force it to output the desired modes.

I also tried to mess around with editing the EDIDs dumped with both HDMI UHD Color On and Off to narrow down the issue.

Any 4K mode that requite the HDMI pixel clock higher than 297 Mhz give "no signal".

Intel driver does not support YCbCr 4:2:2 output. When the EDID report the max.pixel clock of 297 Mhz (UHD Color Off) - Intel driver is using those modes for 4K and they work fine:

4K 24/25/30Hz RGB 8-bit

4K 50/60Hz YCbCr 4:2:0 8-bit

When the EDID report the "high speed" pixel clock mode (594 Mhz) is available - Intel driver is using those modes (and they give no signal):

4K 24/25/30Hz RGB 12-bit

4K 50/60Hz RGB 8-bit

IMO the issue has something to do with Samsung having limited support for 4K RGB modes. It probably expects YCbCr 4:2:2 which Intel does not support.

Quote from piotrasd

I know still are some incompatibility example with Samsung HDR TV, which is actually issue of intel driver/

I tried to figure out what is causing that "no signal" issue on Samsung TV when "HDMI UHD color" is enabled.

At first I thought that Samsung does not support 4K RGB modes with Deep Color. But the odd thing is that when trying 4K 50/60 modes - Intel driver is switching to RGB 8-bit and it doesn't work as well.

So, the only 4K HDMI modes that work with GLK+Samsung TV are:

4K 24/25/30Hz RGB 8-bit

4K 50/60Hz YCbCr 4:2:0 8-bit

Index of /builds/master/Generic/

LibreELEC Testbuilds for x86_64 (Kodi 19.0)

It's a new Comet Lake CPU. No wonder LE 9.2.0 does not support it. Use the Milhouse nightly build.

Use the keymap editor addon to remap the buttons.

Quote from Zygmunt

So projector accepting 4K/60 4:4:4 should work like my VisioTV, it means 2160p/60fps and 4:4:4 or 4:2:2, right?

Sure.

Try the build that I posted here. 4K/60 4:2:0 should be usable.

I compiled a build with working HDR from Kwiboo 's work-in-progress branch. Tested on a Gemini Lake J4105 and Samsung 4K TV. In order for HDR to work go to Settings-->Player and enable "Allow using DRM PRIME decoder".

I believe this projector's HDMI port is limited to a maximum pixel clock frequency of 300mhz. This means it will only support 4K 50/60hz 4:2:0 8-bit.

4K 4:2:0 does not work on standard X11 builds of LibreELEC. AFAIK it's a limitation of Intel driver and/or X11.

Quote from ondertol

i tried with the command

echo 1 > /sys/module/di/parameters/bypass_all

That's only for Amlogic devices.

Quote from bobacisko

So if I understand you right Zotac has DP as 'primary/native' which is the result of the command

and for physical HDMI output it goes via DP to HDMI 2.0 converter.

Yes, Kaby Lake CPUs don't have a native HDMI 2.0 controller, so manufacturers have to use a DP->HDMI 2.0 converter chip.

Quote from bobacisko

Would it make sense to buy DP 2 HDMI cable please?

I don't know. If it is some kind of odd HDMI handshake issue between the Zotac and your new TV I guess that cable could in theory fix that.

Quote from bobacisko

Do not understand why it says DP1 connected when I have HDMI cable

Because your Zotac use a DP to HDMI 2.0 converter chip.