The only package that referenced gtkmm2 was cdrdao to build
an obsolete program, gcdmaster. That program also needed an
obsolete gnome2 library. cdrdao was last updated May 2018.
Since ffmpeg5 no longer carries libavresample, we can't build transcode without
disabling ffmpeg support.. With some rudimentary testing, it seems that this
doesn't have any negative impact.
Currently we only build pipewire for satisfying GNOME building
dependency. I've switched to use Pipewire instead of Pulseaudio as the
audio daemon on my system. For the Pipewire daemon to function
properly, a Pipewire session manager is needed. The upstream recommends
to use WirePlumber.
It's too early to provide instruction for running a Pipewire daemon in
the book, but we can list the external dependency as it does no harm.
Both packages handle libsoup2 and libsoup3 as follows: if one libsoup is
already loaded by the process, it will use the loaded one. Otherwise,
try to load libsoup3 first, and if it's not found try libsoup2.
But they need the headers of one libsoup version at build time to
support loading this version at runtime, so we can't make the libsoups
runtime dependency.
For tracker 3, also demote libsoup2 to recommended. It can be built with
libsoup3 only (and the building system will do it silently if libsoup3
is installed but libsoup2 not). But I'm not sure if it will cause
runtime issues.
There is a new gstreamer vaapi plugin in gst-plugins-bad, which seems
designed for replacing gstreamer-vaapi. But it's still experimental now
and not enabled unless it's set in GST_PLUGIN_FEATURE_RANK explicitly.
I've used this plugin for a while because gstreamer-vaapi does not work
fine on my system with iHD_drv_video.so.
See https://gitlab.freedesktop.org/gstreamer/gstreamer-vaapi/-/issues/312.
Instead of displaying the sysv development url, display the url
corresponding to the revision and release of the book.
Also fix a gst-xxx-version usage.
