The VideoLAN Forums

I embedded album covers into .opus and .m4a music files using kid3-cli, but unfortunately VLC does not show them until a file has been clicked. This is significant for me because the album covers help me recognize files. The album covers of .m4a files are loaded automatically though, this only concerns the .opus files. My VLC version is "3.0.11 Vetinari" (A Debian build from 15 June 2020).
Is there something I can do about this, or it is possible I hit a bug?

I don't believe it's a bug, but more of a feature that has yet to be featured into VLC. Unlike the album art in mp3 files (which has a native support for album art), opus uses the vorbis comment system, and like the name, it is only a comment not a tag system (idv3tag) like in mp3. However, somehow it is possible to turn the image into a video stream, without the need for encoding (processing it into ffmpeg using the command "ffmpeg -i inputsong.opus -f null nul" returns 2 streams, the audio and its metadata, and a video stream saying that it is an "attached pic"(ture) with the metadata saying it's "other"). Most likely m4a also uses some method like this and so it probably requires a constant recursive system to load all the "thumbnails" (just like in file explorer).