========
a2jmidid
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
--------
a2jmidid is a daemon that implements **automatic bridging**.
It has two modes of operation: Running a bridge manually or as a backgrounded
|dbus| service.
Start daemon
____________
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
Start D-Bus service
___________________
In D-Bus service mode, a2jmidid works in the background. When service access is
requested by some application (such as *a2j_control*), the |dbus| 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
--------------
*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
--------------
*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.
.. |jack| raw:: html
JACK
.. |jack2| raw:: html
jack2
.. |dbus| raw:: html
D-Bus
.. |alsa| raw:: html
ALSA