[LAA] [ANN] jack_mixer version 15 released

[Christopher Arndt]

Hello FLOSS audio people!

I'm proud to announce the new release of jack_mixer version 15!

jack_mixer is a GTK+ JACK audio mixer app with a look & handling similar
to hardware mixing desks.

Please visit the project's homepage at rdio.space/jackmixer for more
information.

You can find the new release on Github at:

https://github.com/jack-mixer/jack_mixer/releases/tag/release-15


**Important change:** 'jack_mixer' now uses [meson] for building and
installation. See 'INSTALL.md' in the source for new build instructions.


New:

* A global setting for default project file path was added and can be
  changed in the preference dialog.

    The default value is '$XDG_DATA_HOME/jack_mixer' (which is normally
    '~/.local/share/jack_mixer').

* A "Recent projects" menu was added, to allow loading recently used /
  saved projects more quickly.

* Direct channel output ports are now optional and can be enabled /
  disabled in the channel preferences dialog.

* Ctrl+left-click on the mute ("M") or solo ("S") channel buttons now
  activates exclusive mute resp. solo.

* A man page for 'jack_mixer' was added.

* 'jack_mix_box' now supports the '-p|--pickup' command line option to
  enable MIDI pickup mode, to prevent sudden volume or balance value
  jumps.


Fixed:

* Activating the solo function on an input channel could cause its
  output signal be sent to the monitor outputs instead of the signal
  from the channel, which had monitoring activated.

* Volume and balance level and mute and solo state changes originating
  from the UI now send the correct assigned MIDI CCs, allowing for MIDI
  feedback to controllers. Same for changes originating from reception
  of assigend MIDI CCs.

* The handler for right-clicking the input channel mute/solo buttons,
  was accidentally removed and is now re-instated.

* Creating a new output channel assigns it a randomly chosen color,
  which can be changed in the new channel dialog (used to work
  some releases ago, but was broken at some point).

* The 'jack_mix_box' command line options '--help' and '--stereo'
  erroneously required an argument.

* Saving the current project on reception of the 'SIGUSR1' signal, which
  is a requirement for LADISH level L1 support, was broken in version
  14.

* When re-ording channels via drag-and-drop, the order of the edit /
  remove channel menu items were not updated.

* When creating an output channel, it could happen that the initial
  channel volume would ranmdomly be set to -inf or 0 dB, regardless of
  what was selected in new channel dialog.


Changed:

* The minimum supported Python version is now 3.6.

* The 'jack_mix_box' command line usage help message was improved.

* The channel strip buttons (solo, mute, etc.) now have more distinctive
  colors when activated or the mouse hovers over them.

* The balance slider step size was increased slightly so right-clicking
  the slider changes the value more rapidly.

* When using the "Save as..." function, 'jack_mixer' now sets the
  default filename and directory for file chooser to the last ones used.

* A window title was added to the preferences dialog.

* MIDI control for mute and solo now interprets control value 0-63 as
  off and 64-127 as on, instead of toggling the state on reception of
  any controller value.


Project infrastructure and internals:

* The 'jack_mixer_c' Python extension module, which was originally
  implemented in hand-written C code using the PYTHON C API, was
  replaced with the '_jack_mixer' extension module implemented in
  Cython, which  generates the C code in '_jack_mixer.c'.

* The autotools build toolchain was replaced with a build setup using
  meson, which improves build times and maintainability markedly. See
  the file 'INSTALL.md' for updated build and installation instructions.

* A build option to allow buidling only 'jack_mix_box' was added
  ('-Dgui=disabled').

* All Python code was re-formatted with [black].

* All errors and warings reported by [flake8] were fixed or are
  expressively and selectively ignored.

* The file 'version.py' is now generated from the version set in the
  project definition in the top-level 'meson.build' file, leaving this
  as the only place where the version number needs to be updated before
  a release.

* The 'NEWS' file was renamed to 'CHANGELOG.md' and converted to
  Markdown format.

This release was created by Christopher Arndt. With a contribution from
Athanasios Silis.


Share & enjoy!


Christopher Arndt