JACK_MIX_BOX(1) audio JACK_MIX_BOX(1)

jack_mix_box - A minimal JACK audio mixer with MIDI volume control

jack_mix_box [-n <name>] [-p] [-s] [-v <dB>] MIDI_CC...

This manual page documents the jack_mix_box command.

jack_mix_box is a minimal, GUI-less version of jack_mixer. It creates a JACK client with stereo output ports and a fixed number of mono or stereo input ports. The number of input ports and the MIDI Control Change message controlling the volume level of each is set via the command line. The signal of each input channel is mixed into the stereo outputs.

Positional arguments:

MIDI_CC... add input channel controlled by MIDI_CC

Optional arguments:

print this help message
set JACK client name
enable MIDI pickup mode (default: jump-to-value)
make all input channels stereo with left+right input
initial volume gain in dBFS (default 0.0, i.e. unity gain)

Each positional argument is interpreted as a MIDI Control Change number and adds a mixer channel with one (mono) or left+right (stereo) inputs, whose volume can be controlled via the given MIDI Control Change.

Use jack_connect or any other JACK conmection manager to connect other JACK clients or system ports to the input and output port.

Send a SIGUSR1 signal to the jack_mix_box process to have the current volumes per input channel reported to the standard output.

  • For each input channel, jack_mix_box will create one (if it is a mono channel) or two (stereo) JACK audio input ports. The input port(s) will be named "Channel <n>", where "<n>" is the channel number, and have an " L" resp. " R" suffix, it the channel is stereo.
  • It will create two JACK audio output ports named "MAIN L" and "MAIN R".
  • It will also create one JACK MIDI input ("midi in") and one MIDI output ("midi out") port.

The first of these environment variables set to a non-empty value is used to determine the language(s) for loading gettext translation files. The value should be a colon separated list of language codes.
The language set via this environment determines the floating point number format used to parse volume levels given on the command line and to format them in the output. If LC_NUMERIC is not set, its value is inherited from one of the language environment variables described above.
With this environment variable, the base directory for the gettext translation files can be changed from the default set at compile time, which is usually <prefix>/share/locale.

Send SIGUSR1 to the jack_mix_box process to have the current volumes reported per input channel.

Nedko Arnaudov <nedko@arnaudov.name> (original author), Frédéric Peters <fpeters@0d.be> (current maintainer).

GNU General Public License Version 2

2021-04-14 19