| Jack MIDI Interface |
|---|
Enable Jack MIDI in your configuation file:
;; Add to ~/.incudinerc (setq *enable-jack-midi* t)
We can open/close JACKMIDI:STREAM's before or after the Jack startup.
For example:
SCRATCH> (defvar *midiin* (jackmidi:open))
creates and returns a new JACKMIDI:INPUT-STREAM (the
keyword :DIRECTION is :INPUT by default).
SCRATCH> (jackmidi:input-stream-p *midiin*)
T
The name of the port for a JACKMIDI:INPUT-STREAM
is "midi_in" by default
SCRATCH> (jackmidi:port-name *midiin*) "midi_in"
but it is possible to use the keyword :PORT-NAME
to set another name (an error is thrown if the name is used).
JACKMIDI:PORT-NAME is SETFable and we can change the port name before
to start Jack (the new name is ignored if Jack is running).
The ports are automatically registered after RT-START
and unregistered after RT-STOP.
SCRATCH> (rt-start) SCRATCH> (defvar *midiout* (jackmidi:open :direction :output)) SCRATCH> (jackmidi:output-stream-p *midiout*) T SCRATCH> (jackmidi:port-name *midiout*) "midi_out"
We can add other MIDI ports:
SCRATCH> (defvar *midiin2* (jackmidi:open :port-name "midi_in 2")) SCRATCH> (defvar *midiout2* (jackmidi:open :direction :output :port-name "midi_out 2"))
JACKMIDI:ALL-STREAMS returns a new list with the
opened Jack MIDI streams. It also works if Jack is stopped:
SCRATCH> (jackmidi:all-streams) (#<JACKMIDI:INPUT-STREAM "midi_in"> #<JACKMIDI:OUTPUT-STREAM "midi_out"> #<JACKMIDI:INPUT-STREAM "midi_in 2"> #<JACKMIDI:OUTPUT-STREAM "midi_out 2">) SCRATCH> (jackmidi:all-streams :input) (#<JACKMIDI:INPUT-STREAM "midi_in"> #<JACKMIDI:INPUT-STREAM "midi_in 2">) SCRATCH> (jackmidi:all-streams :output) (#<JACKMIDI:OUTPUT-STREAM "midi_out"> #<JACKMIDI:OUTPUT-STREAM "midi_out 2">)
There are two ways to close a JACKMIDI:STREAM
SCRATCH> (jackmidi:close *midiin*) SCRATCH> (jackmidi:close "midi_in 2") ; by name
JACKMIDI:GET-STREAM-BY-NAME is useful if we don't
use a variable:
SCRATCH> (jackmidi:get-stream-by-name "midi_out") #<JACKMIDI:OUTPUT-STREAM "midi_out">
JACKMIDI:WRITE-SHORT sends a MIDI message encoded
into a 32bit word; for example, a note-on:
SCRATCH> (at (now) #'jackmidi:write-short *midiout*
(jackmidi:message 144 60 96) 3)
If you test the MIDI output with the jack_midi_dump
command, after the following line:
SCRATCH> (at (+ (now) 23) #'jackmidi:write-short *midiout*
(jackmidi:message 128 60 0) 3)
the output of jack_midi_dump is
23: 80 3c 00 note off (channel 0): pitch 60, velocity 0
and you can notice that the frame number is precise.
We can send octets by using the function JACKMIDI:WRITE
SCRATCH> (defvar *msg0* (make-array 6 :element-type '(unsigned-byte 8) :initial-contents '(#xf0 #x7e #x7f #x09 #x01 #xf7))) SCRATCH> (jackmidi:write *midiout* *msg0*) SCRATCH> (jackmidi:write *midiout* (jackmidi:data #xf0 #x7e #x7f #x09 #x01 #xf7)) SCRATCH> (defvar *msg1* (coerce '(144 60 96 128 60 0 176 7 99) 'jackmidi:data)) SCRATCH> (jackmidi:write *midiout* *msg1* :end 3) ; note on SCRATCH> (jackmidi:write *midiout* *msg1* :start 3 :end 6) ; note off SCRATCH> (jackmidi:write *midiout* *msg1* :start 6) ; cc 7
If a MIDI message is stored into a foreign buffer, we can use
JACKMIDI:FOREIGN-WRITE to send that message.
JACKMIDI:READ fills a buffer with the events received
from a JACKMIDI:INPUT-STREAM. The version to fill a
foreign buffer is called JACKMIDI:FOREIGN-READ.
Jack MIDI input works fine with RECV-START and RECV-STOP:
SCRATCH> (defparameter *midiin* (jackmidi:open)) SCRATCH> (setf (logger-level) :info) SCRATCH> (defvar *midi-dump-test* (make-responder *midiin* (lambda (st d1 d2) (cond ((jackmidi:sysex-message-p st) (msg info "~S" (jackmidi:input-stream-sysex-octets *midiin*))) (t (msg info "~D ~D ~D" st d1 d2)))))) SCRATCH> (rt-start) SCRATCH> (recv-start *midiin*) ;; playing...
JACKMIDI:INPUT-STREAM-SYSEX-OCTETS returns a
buffer with the octets of the last received SysEx message.
If the second optional argument is a lisp buffer of type
JACKMIDI:DATA, that buffer is filled with the received SysEx
message.
JACKMIDI:INPUT-STREAM-SYSEX-POINTER returns two
values, the pointer to the foreign buffer that contains the last
received SysEx and the length of the message in bytes. If the
second value is zero, there isn't a cached SysEx message and
the foreign buffer is to ignore.
JACKMIDI:INPUT-STREAM-SYSEX-TIMESTAMP and
JACKMIDI:INPUT-STREAM-SYSEX-SIZE return the
timestamp and the length of the last SysEx message, respectively.
;; ...stop SCRATCH> (recv-stop *midiin*) SCRATCH> (remove-responder *midi-dump-test*) SCRATCH> (rt-stop) SCRATCH> (setf (logger-level) :warn)
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