4k 60hz not detected using Onkyo TX-SR393

Ack3r · December 7, 2019 at 9:28 PM

When using my Pi4 through an Onkyo TX-SR393 the Pi 4 will not output in 60hz. Only at 30hz.

The Xbox 1 which is also plugged into the Onkyo will passthrough 60hz but uses YCbCr420 24bit.

I have the following in my config.txt

# 4k 60hz Support

hdmi_enable_4kp60=1

hdmi_group=1

hdmi_mode=97

Interesting enough my TV a TCL 55r625 does allow 60hz, and I can move the HDMI from the TV to the AVR and the AVR will pass the 60hz signal.

Onkyo supports the following:

4K (3840×2160p) 50/60 Hz, 4K SMPTE (4096×2160p) 50/60 Hz : RGB/
YCbCr4:4:4 (8 bit), YCbCr4:2:2 (12 bit), YCbCr4:2:0 (8/10/12 bit)

TCL supports the following and I have the HDMI Input set for 2.0

4k @ 60 Hz : Yes

4k @ 60 Hz @ 4:4:4 : Yes

Using TVService mode 97 is missing when plugged into the Onkyo but shows when plugged into the TCL.

Is there a way to hardcode the resolution I want?

Thanks

**Da Flex** · December 7, 2019 at 10:51 PM Official Post

Using config.txt is the right way to hardcode a resolution. Please verify this values:

Quote from Ack3r

hdmi_group=1

hdmi_mode=97

According to this, the values might be wrong.

Ack3r · December 9, 2019 at 3:33 AM

My TV supports the mode, just not from the AVR.

I can force the 4k60hz signal using tvservice -e "CEA 97" but this introduces judder so this isn't ideal.

**Da Flex** · December 9, 2019 at 4:19 AM Official Post

Looks like HDMI does the negotiation for the signal chain, and chooses the best mode for all devices.

If you hardcode the mode, it will have no effect, because you have one device, which is not compatible to the selected HDMI mode.

**Da Flex** · December 9, 2019 at 5:42 PM Official Post

Suggested solution: Buy an HDMI audio splitter, and go audio-only (optical S/PDIF) from splitter to AVR.