This project aims to ease the usage of legacy, non JACK enabled applications, in a JACK MIDI enabled system, when using jack2
There are two ways to use legacy ALSA sequencer applications in a JACK MIDI system:
Automatic bridging: For every ALSA sequencer port you get one JACK MIDI port. If an ALSA sequencer port is both an input and an output, you get two JACK MIDI ports, one input and output. (This approach works almost always except when the legacy ALSA sequencer application does not create ports and/or wants to use an existing port to capture from or playback to. Such programs are using a feature of the |alsa| sequencer framework that allows sending and receiving MIDI events to/from a port, without creating a connection to it.)
Static bridges: You start an application that creates one ALSA sequencer port and one JACK MIDI port. Such a bridge is unidirectional.
For details on how to build and install this project, look at INSTALLATION.rst.
a2jmidid is a daemon that implements automatic bridging.
It has two modes of operation: Running a bridge manually or as a backgrounded D-Bus service.
To start a2jmidid in manual mode, just run the executable. a2jmidid will start bridging, and you will get output on stdout and stderr. You can stop the bridge using ctrl-c.
Usually you want to bridge software ports and not bridge hardware ports (they are handled by JACK itself). In case you want to force a2jmidid to bridge hardware ports nonetheless, you can use the according flags:
a2jmidid -e
or:
a2jmidid --export-hw
In D-Bus service mode, a2jmidid works in the background. When service access is requested by some application (such as a2j_control), the D-Bus session bus daemon activates the object by executing the service executable.
The object has methods for starting and stopping the bridging. You can use a2j_control to do this:
a2j_control --start a2j_control --stop
You can deactivate (that may cause later reactivation) the service like this:
a2j_control --exit
You can query the bridge status using this command:
a2j_control --status
There also methods (and corresponding a2j_control commands) that can be used to query mapping information:
a2j_control --help
The a2jmidid implementation is based on jack-alsamidi-0.5, which is (almost) identical to the jackd ALSA seq MIDI backend), both created by Dmitry Baikov.
a2jmidi_bridge creates a static bridge between one ALSA sequencer playback port and one JACK MIDI capture port. MIDI events sent to the ALSA sequencer playback port can be read from the JACK MIDI capture port.
a2jmidi_bridge has an optional argument that allows overriding the name used for the JACK and ALSA client:
a2jmidi_bridge "my precious bridge"
The a2jmidi_bridge implementation is based on alsaseq2jackmidi by Sean Bolton.
j2amidi_bridge creates a static bridge between one JACK MIDI playback port and one ALSA sequencer capture port. MIDI events sent to JACK MIDI playback port can be read from the ALSA sequencer capture port.
j2amidi_bridge has an optional argument that allows overriding the name used for the JACK and ALSA client:
j2amidi_bridge "my precious bridge"
The j2amidi_bridge implementation is based on jackmidi2alsaseq by Lars Luthman.