media-libs/xine-lib should have slot operator for media-libs/libaom so that a rebuild could be triggered in this case.
!!! existing preserved libs:
>>> package: media-libs/libaom-3.0.0
* - /usr/lib64/libaom.so.2
* - /usr/lib64/libaom.so.2.0.0
* used by /usr/lib64/gstreamer-1.0/libgstaom.so (media-libs/gst-plugins-bad-9999)
* used by /usr/lib64/xine/plugins/2.9/xineplug_decode_libaom.so (media-libs/xine-lib-1.2.11)
Use emerge @preserved-rebuild to rebuild packages using these libraries
* After world updates, it is important to remove obsolete packages with
* emerge --depclean. Refer to `man emerge` for more information.
Looks like xine-lib-1.2.11 has a default enabled --with-libaom configure option, which triggers this whenever libaom is installed.
I'll take the liberty to add one more that's also missing to the same bug.
$ grep dav1d NEEDED
* video decoder plugins:
- MPEG 1,2 (libmpeg2)
- Amiga Bitplane
- Raw RGB
- Raw YUV
- libaom (AV1)
- dav1d (AV1)
(disabled plugins: dxr3 gdk-pixbuf image libjpeg theora w32dll vdpau mmal libvpx OpenHEVC)
Thanks Ionen, I noticed it and was thinking about adding it but didn't do it, because I was unsure.