@robertoj: $ ffmpeg ffmpeg: symbol lookup error: ffmpeg: undefined symbol: av_buffersrc_get_status, version LIBAVFILTER_10 Looks like Friendlyelec deleted some functions in their version of the library, or based it on an outdated version. ffmpeg is version 7:7.1.5-0+deb13u1 Filename: pool/main/f/ffmpeg/ffmpeg_7.1.5-0+deb13u1_arm64.deb MD5sum: 18e560e3b4c4b992d74d2bf3020d9a53 No v4l2request info with `mpv -v`

@eselarm: Thanks enormously for this information. I'm not a hardware expert, so much of this is over my head, but you clarified a number of things for me right away and raised a new bunch of questions. Will research things further. One correction: the Friendlyelec libav* libraries are under /usr/local and take preference to those under /usr, so they won't be affected by a Debian update.

That's the advantage when you use a device that doesn't have a PMIC and only goes into deep sleep mode for Off Mode. This is only supported by the proprietary, closed-source manufacturer firmware, for which of course no publicly available API description exists. Mainline support will therefore most likely not become available. So it basically just leaves reverse engineering and an out-of-tree implementation. Good luck.

moved to tvboxes

The board should have RT8821CU as wifi chip. Since Linux 6.17 there is no out of tree driver necessary anymore, mainline i used. So perhaps this is a an issue or regression upstream. You can try to switch to edge kernel, perhaps this has been addressed but not back-ported.