Add an `always_off` option to outputs that causes them to never start
playback even if they're enabled.
This allows placeholder `null` outputs to be defined for the purpose
of having an external client react to the enabled state without the
side effects of real outputs. Like an external mixer, the client can
perform some action when an output is enabled.
Normally `null` outputs can be used for playback so it's possible for
MPD to continue playback silently if a problem occurs with all the real
outputs (or there are none enabled).
Boost makes building a piece of software much more difficult than
necessary. It's a huge library, and just uncompressing it takes a
considerable amount of time. MPD only used a tiny fraction of it, yet
its header bloat made the MPD build very slow. Locating Boost was
difficult due to its arcane build system and its resistance to use
pkg-config; it's always a special case. MPD could never use features
of newer Boost versions because Linux distributions always shipped old
Boost versions. Boost made everything complicated and slow.
So, finally, after getting rid of GLib (commit ccdb94b06c), switching
to C++ and using Boost (commit 0801b3f495), we've finally get rid of
it 8 years later.
Unfortunately, I had to reimplement parts of it along the way
(e.g. IntrusiveList). Kind of NIH, but on the other hand, compiling
MPD has become much easier for users.
The writing and reading of metadata involves lots of different programs
and libraries. Therefore it is prudent to point out how exactly MPD
receives metadata. Ideally this helps to point users to the right place
if their tags are not picked up correctly.
NB: Check the sysconfdir setting to determine where mpd will look for mpd.conf; if you expect mpd to look for /etc/mpd.conf the sysconfdir must be '/etc' (i.e., not 'etc' which will result in mpd looking for /usr/local/etc/mpd.conf):
.. code-block:: none
meson configure output/release |grep sysconfdir
If this is not /etc (or another path you wish to specify):
.. code-block:: none
$ meson configure output/release -Dsysconfdir='/etc' ; meson configure output/release |grep syscon
sysconfdir /etc Sysconf data directory
This allows users to disable the "CUE files as directories" feature
without having to disable the CUE playlist plugin completely. This
feature has been annoying some users.
