Using cec-client with a raspberry pi on debian or ubuntu does not work out of the box, as the cec-client in the debian and ubuntu repositories has not been compiled with support for the propriary raspberry libraries. In addition, these libraries are 32-bit only. This is a guide in how to get this working.
First you need to set up a 32-bit chroot environment. Install debootstrap and then run
debootstrap --variant=buildd --arch=armhf bullseye /opt/cec-client/ You will then need to download the raspberry pi libraries.
