Features, settings & updates

[ric982]

I've got the following connections:

Roku Express 4K+ -> Anthem AVM 70 8K AV Preprocessor -> LG OLED55C1PUB TV

The AVP and TV are both HDMI 2.1. AVP supports HDR10 4K/60, 4K/120, 8K/60. The TV supports HDR 10. There aren't any controls to select HDMI 1.4.

By BDP is playing 4K Dolby Vision through the AVP to TV without problems.

During setup, the Roku selected Display Mode: Automatic (HDR10 1080p). I was worried this might affect 4K operation in general, so I set it to 4K HDR TV (which is what I have). But it says "Your current TV or AV receiver settings can display 4K HDR10 at 30 frames per second (not recommended). For help... go.roku.com/HDR." I didn't see any of the settings they mention on the LG and I don't see anything that would help on the Anthem.

I know the Express doesn't support Dolby Vision. Is it limited to 4K 30FPS for HDR10?
Why does it say my TV settings do not support 4K/60 HDR10?

[ric982 · Accepted solution]

So I didn't get this message from the LG TV initially, but after some re-cabling and a lot of playing around with settings, a message popped up about changing a setting to optimize the display or something like that.

The setting that needs changing on an LG C1 (or maybe any LG Cx or Gx model) is:

Settings button on Remote> All Settings>  General> Devices> HDMI Settings> HDMI Deep Color: Select 4K.

After setting this, the Roku no longer complains about the TV/AVR not being setup for 4K/60 and does play 4K/60 from channels that have media that is in this format, including: Amazon Prime (Casino Royal), Acorn (Monsieur Spade), Britbox (Father Brown Season 11e1). The TV is also showing 4K/60 as a Mac 2nd Display.

The Roku is playing through the AVM 70 8K - but I think the video is just passed through so it shouldn't matter. The Mac Studio is connected through a Hyper Hyper Drive 8K USB-HDMI Adapter to the LG

Using the LG remote inputs selector, selecting Dashboard, and then selecting the input with the Roku, displays Dolby Vision (temporarily in upper right corner). Pressing the remote green button about 6 times opens the VRR info display and the above mentioned Roku channels show:

60.0 Hz, FIXED, 3840 x 2160P@60Hz YCBCR422 8b TM.

Before the setting change I was getting 30 Hz, so the setting fixed the 60 fps issue. There is chatter on the web about whether the LG can detect 10b/12b color when it reports the color depth (e.g. it may just say 8b in all cases), but the C1 is supposed to support 10 bit color and perhaps it is displaying it OK (just not reporting it correctly). The picture image is stunning.

FWIW - the Mac Studio USB > USB-HDMI Adapter ->L G 2nd monitor display is showing:

60 Hz, FIXED, 3840 x 2160P@60, YCBCR444 8b 4L10. 

LG Firmware Level: 03.36.50 (current level @ 1/2024).