Vero4K+ strange CEC behaviour


I’ve decided to create a thread here after searching the forums and not getting the right information.

With both my previous Nvidia Shield TV, as well as S905 box running Libreelec, CEC has always worked out of the box perfectly for my setup, namely, using my TV box remote to do everything I needed: power on projector and AVR, power off all devices, volume control for my AVR etc. Most importantly volume control my passthrough audio.

Similarly, I would like my Vero 4K+ remote to control my passthrough audio on my AVR but I can’t get it to work.

I have upgraded my projector early in the year to an Optoma UHD40 which seemingly does not support CEC so perhaps that is the cause of my problems. The AVR (Denon AVR-X1400H), HDMI cables, etc is all the same and known to be working and set up correctly.

I don’t mind getting my hands dirty, it’s just I have no idea what to do further.

For starters here’s what I see when I run cec-client:


I’ve always found implementation of CEC on Optoma projectors to basically be a write off when using an AVR.

I’ve found this with HD23, HD25 and UHD-51A.

If you run things to your AVR and another display as a test I suspect you’ll find things work.
Can you confirm that your Shield and S905 box with LE still work as expected on the new PJ? I’ll be surprised if this is the case, and if it is, it means it’s something we can fix.

I’ve mentioned this to Optoma. The UHD51-A supports OTA firmware updates, which is why I chose it over the UHD51 (I’m not interested in Alexa). So there’s some promise of a resolution in the future.

I assume you’re trying to control your volume with the OSMC RF remote controller?


Hi @sam_nazarko

I’ve had back and forth interaction with head of Optoma UK support and they were very ignorant of the facts that I have given them (about another, unrelated, firmware bug) so good luck with that. Their extremely poor level of support, and patronizing and condescending attitude only makes me appreciate it all the more that you are giving proper support for your OSMC hardware, so sincerely thank you for this, this is exactly why I bought into OSMC

I’ve since sold my Shield because the UHD40 couldn’t display standard 4K bluray content (10bit 4:2:0 YUV bt2020) properly without colour banding when the content was passed in 23.98 Hz at 12bit 4:2:2 YUV so again, Vero 4K+ wins the Shield in that department because it outputs the same 23.98 hz content @ 10bit 4:4:4 (YUV) bt2020 which my projector can display without banding.

Back on topic, my old Optoma HD142X worked fine with CEC, like powering on and off together with AVR controlled by Libreelec on a box with S905 chipset.

I can indeed confirm that out of the box the Nvidia Shield TV as well as my old Libreelec box can control volume on my AVR without any additional settings/tweaks, even on the new UHD40 projector as my display.

I am trying with both OSMC RF remote control as well as my favourite remote, the Xiaomi TV box BT remote (non-voice control). The latter worked straight away after pairing so that was really pleasant. I also attempted remapping volume control with Keymap editor but I assume it didn’t really change anything because it still tries to control the kodi volume, nothing with CEC that I can see.


Obviously I can’t comment with regards to your experience with them, but hopefully I’ll have more luck than you here. I can prove where CEC is being problematic in the chain, and it’s overwhelmingly on the Optoma’s end in negotiation and RX.

Can you upload debug logs from one of those systems, ideally LE as it’s Linux based, and then OSMC so I can compare things?

Can you also ensure that on both tests they’re connected to the same HDMI ports (both in to AVR and AVR out) as well as with the same peripherals attached to AVR/TV?



Hi @sam_nazarko

As per your request, I have swopped out the Vero4K+ with my S905 libreelec box, keeping the cables and everything the same. I used Vero’s remote on both, but on the Libreelec box I had to remap VolumeUp to the stop key with Keymap Editor for this test as it did not detect the volume buttons.

Vero4K+ logs:

LibreElec box kodi logs:

LibreElec box sys logs:

Test setup:

Box under test → Denon AVR-X1400H → Optoma UHD40

I pressed the relevant volumeup key.

On the Vero4K+ VolumeUp attempts only to control onscreen volume which does not affect passthrough audio because it does not control the volume on my AVR via CEC.

On the LibreElec box VolumeUp successfully sends CEC volume command to AVR as expected, AVR volume increases.

Thanks for your assistance

That’s odd. Are you using an old version of LibreELEC? Support was added to LE in February 2018.

Are you definitely testing on the same versions of Kodi (both 18.3)?

Hi @sam_nazarko

No - my Vero4K+ is fully updated and the LibreElec box runs an old community build.

The LibreElec box has the following version info:
OS: LibreELEC (community): (kernel: Linux 3.14.29)
Kodi: 17.6 Git:a9a7a20

Ah, that probably explains the difference. That LE build will have a much older version of CEC.

I will look in to it.

I’m not sure what CEC version you are talking about specifically, not sure if this is useful but cec-client outputs a version as “libCEC version 4.0.2”

Yes. We are on 4.0.4 here. Will check it out.

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Hi @sam_nazarko let me know if I can assist with anything to help find a solution

Still looking in to this.

On the subject of strange CEC behaviour, I’ve been having a battle with my AVR-connected Vero, when I switch source away from the Vero, the Vero insists on switching it back to the Vero. A serious pain. Not sure which OSMC update introduced this, never used to have the problem. I might have fixed it by disabling CEC, rebooting, then restarting CEC and rebooting again. If the problem returns I may just have to disable CEC entirely as a workaround?

What is the make and model of the TV?

My AVR is a Marantz NR1603, and the TV is a Panasonic TX-P46G20BA. At some point in the last few months, switching the source on the Marantz away from the Vero has become glitchy. My son has complained about that when trying to use the PS4, and I noticed it when trying to switch to my Apple TV box. The AVR would temporarily switch to the desired source, but then back to the Vero. Through random rebooting, I might have fixed it, will monitor, and if I can find a reproducible way of creating the problem, will post an update.

I can’t think of anything off the top of my head that would cause this.
The CEC implementation is somewhat static; beyond the occasional attempts to fix LG connectivity issues.

I’ve noticed the same on my NR1608. Reboot has stopped it for a while. The amp will also occasionally switch itself off as soon as I’ve switched it on (vero input) but stays on the second time.

@figrin_dan, for how long have you had this behaviour with the NR1608? I’ve been running a Vero into my NR1603 for quite a while now, and this issue with the random over-ride of source switching has only come up in the last few months or so, which seems to point to OSMC (the firmware on the NR1603 has not been updated since December, so that can’t be a factor).

I couldn’t really say for sure. I got the Vero just over a year ago and have had all sorts of problems with it powering on/off, TV and amp changing inputs and the vero switching itself on when I don’t want it to. Sometimes a reboot appears to fix a fault but then it comes back later. I’m not sure if it’s CEC or some other thing but if I switch CEC off seems to help until I get fed up with juggling remotes and try it again.

This is still a problem for me. I have to keep two remotes with me, one for controlling the volume on my AVR and one for Vero 4K+ operation. I don’t have any other CEC capable display to see if CEC will then work correctly. I really hope we can find a solution to get this working like it used to on my former Libreelec box.