Merge pull request #3 from oplS17projects/rtmidi-interface-dev

Experimental set of rtmidi interface procedures

rtmidi_interface.rkt

@@ -25,68 +25,186 @@
 ;; -	install --mode=644 RtMidi.h RtError.h $(PREFIX)/include
 
 
-
+; to set up a port use the following call sequence
+
+; (define in (make-in-port))
+; (define out (make-out-port))
+; (open-in-port in "MIDI-DEVICE")
+; (open-out-port out "MIDI-DEVICE")
+
+; replace "MIDI-DEVICE" with the appropriate midi device by calling the
+; following procedures to find the name of the available devices
+; the (open-in-port) and (open-out-port) procedures pick the first
+; available port that has a name that contains "MIDI-DEVICE" as a substring
+
+; (list-in-ports in)
+; (list-out-ports out)
+
+; the usb to midi cable I have is shown as
+
+; "a2j:Turtle Beach USB MIDI 1x1 [20] (capture): Turtle Beach USB MIDI 1x1 MIDI "
+; and
+; "a2j:Turtle Beach USB MIDI 1x1 [20] (playback): Turtle Beach USB MIDI 1x1 MIDI "
+
+
+
+; for mor information about the midi specifications, see www.midi.org/specifications
+; refer to the General midi specification level 1
+
+
 ; Create RtMidiIn and RtMidiOut
-(define in (make-rtmidi-in))
-(define out (make-rtmidi-out))
-
-; List input and output ports
-(define in-ports (rtmidi-ports in))
-(printf "Input ports: ~a~n" in-ports)
-
-(define out-ports (rtmidi-ports out))
-(printf "Output ports: ~a~n" out-ports)
-
-; Open the first input and output port, if any
-
-(match in-ports
-  [(cons a-port other-ports) (rtmidi-open-port in 0)]
-;;  [other (printf (current-error-port) "no input ports\n")])
-  [other (printf "no input ports\n")])
-
-(match out-ports
-  [(cons a-port other-ports) (rtmidi-open-port out 0)]
-;;  [other (printf (current-error-port) "no output ports\n")])
-  [other (printf "no output ports\n")])
+(define (make-in-port) (make-rtmidi-in))
+(define (make-out-port) (make-rtmidi-out))
+
+;list input and output ports
+(define (list-in-ports in) (rtmidi-ports in))
+
+(define (list-out-ports out) (rtmidi-ports out))
+
+
+; Open the specified midi ports for input and output
+(define (in-ports-length in) (length (list-in-ports in)))
+(define (out-ports-length out) (length (list-out-ports out)))
+
+
+(define (open-in-port in-port name)
+  (define i 0)
+  (for ([j (in-range (in-ports-length in-port))])
+    #:break (string-contains? (list-ref (list-in-ports in-port) i) name)
+    (set! i j))
+  (if (not (= i (in-ports-length in-port)))
+        (rtmidi-open-port in-port i)
+        (printf "Port ~a not found" name)))
+
+
+(define (open-out-port out-port name)
+  (define i 0)
+  (for ([j (in-range (out-ports-length out-port))])
+    #:break (string-contains? (list-ref (list-out-ports out-port) i) name)
+    (set! i j))
+  (if (not (= i (out-ports-length out-port)))
+      (rtmidi-open-port out-port i)
+      (printf "Port ~a not found" name)))
+
+; Close the in port
+(define (close-in-port in-port) (rtmidi-close-port in-port))
+
+; Close the out port
+(define (close-out-port out-port) (rtmidi-close-port out-port))
+
+; Sends a midi message to the port
+(define (send-midi-message port status data1 data2)
+  (rtmidi-send-message port (list status data1 data2)))
 
-(define (send-midi-message status data1 data2) (rtmidi-send-message out (list status data1 data2)))
+; Read a midi message from the port
+(define (read-midi-message port)
+  (sync port))
 
-(define (play-midi-note length note on-veloc off-veloc channel) (thread (lambda () (begin (send-midi-message (+ channel 144) note on-veloc)
-                                                                               (sleep length)
-                                                                               (send-midi-message (+ channel 128) note off-veloc)
-                                                                               (printf "note sent (play-midi-note)\n")))))
 
-(sleep 15)
 
-(play-midi-note 2 64 93 64 0)
+;; all values start from 0
+;; channel 1 is channel number 0, channel 10 (purcusion) is channel number 9
 
-(printf "note sent (main)\n")
+; Procedures for sending midi messages
+
+(define (note-off port channel note) (send-midi-message port (+ 128 channel) note 0))
+(define (note-on port channel note velocity) (send-midi-message port (+ 144 channel) note velocity))
+
+; plays a note for a specified length of time in seconds, length can have arbitrary precision
+(define (play-note port channel note velocity length)
+  (thread (lambda () (note-on port channel note velocity)(sleep length)(note-off port channel note))))
+
+; polyphonic key pressure (aftertouch)
+(define (poly-key-pressure port channel note pressure) (send-midi-message port (+ 160 channel) note pressure))
+(define (control-change port channel controller value) (send-midi-message port (+ 176 channel) controller value))
+; program change is tone select
+(define (program-change port channel program) (send-midi-message port (+ 192 channel) program 0))
+; channel-pressure (aftertouch)
+(define (channel-pressure port channel pressure) (send-midi-message port (+ 208 channel) pressure 0))
+; pitch bend value is a 14 bit value, center (no change) is 8192 or lsb=0 msb=40
+(define (pitch-bend port channel lsb msb) (send-midi-message port (+ 224 channel) lsb msb))
+
+
+; control changes and mode changes
+(define (bank-select port channel bank tone)
+  (thread (lambda ()
+            (send-midi-message port (+ 176 channel) 0 bank)
+            (send-midi-message port (+ 176 channel) 32 0)
+            (program-change port channel tone))))
+
+(define (channel-volume-change port channel volume)
+  (send-midi-message port (+ 176 channel) 7 volume))
+
+;left-right balance
+(define (set-pan port channel pan)
+  (send-midi-message port (+ 176 channel) 10 pan))
+
+
+; expression controller
+(define (set-expression-controller port channel expression-value)
+  (send-midi-message port (+ 176 channel) 11 expression-value))
+
+
+; hold1 (sustain) pedal. set on to #t to enable sustain, set on argument to #f to turn off
+(define (set-sustain port channel on)
+  (send-midi-message port (+ 176 channel) 64 (if on 64 0)))
+
+; Sostenuto pedal
+(define (set-sostenuto port channel on)
+  (send-midi-message port (+ 176 channel) 66 (if on 64 0)))
+
+; Soft pedal
+(define (set-soft-pedal port channel on)
+  (send-midi-message port (+ 176 channel) 67 (if on 64 0)))
+
+
+
+
+
+
+;;(define (play-midi-message-list lst) (begin (sleep (car lst)) (send-midi-message (cadr lst) (caddr lst) (cadddr lst)) (if (null? (cddddr lst)) 0 (play-midi-message-list (cddddr lst)))))
+
+;;(define (parse-midi-message-list lst (
+;; this will eventually be able to take a list of midi messages and create a list of midi notes and other midi messages
+
+
+;(sleep 15)
+
+;(play-midi-note 2 64 93 64 0)
+
+;(printf "note sent (main)\n")
 
-(define (play-note note)
+;(define (play-note note)
 ; Send a note
-(rtmidi-send-message out (list (* 11 16) 7 128))
-(printf "sending note~n")
-(rtmidi-send-message out (list 144 65 96))
-(sleep 2)
-(rtmidi-send-message out (list 128 65 64))
-(printf "note sent~n"))
+;(rtmidi-send-message out (list (* 11 16) 7 128))
+;(printf "sending note~n")
+;(rtmidi-send-message out (list 144 65 96))
+;(sleep 2)
+;(rtmidi-send-message out (list 128 65 64))
+;(printf "note sent~n"))
 
 
 ;(sleep 10)
 
 ;(play-note)
 
 
-(define (listen-midi-events)
+;(define (listen-midi-events)
 ; Read incoming messages until break
-(let loop ()
-  (pretty-print (sync in))
+;(let loop ()
+;  (pretty-print (sync in))
 ;  (play-note)
-  (loop))
-)
+;  (loop)))
+
+;(define listenthread (thread listen-midi-events))
+
+;(sleep 60)
 
-(define listenthread (thread listen-midi-events))
+;(kill-thread listenthread)
 
-(sleep 60)
+;(define (echo-midi-events)
+;  (let loop ()
+;    ((lambda (evnt) (pretty-print evnt)(sleep (car evnt))(send-midi-message (cadr evnt) (caddr evnt) (cadddr evnt))) (sync in))
+;    (loop)))
 
-(kill-thread listenthread)
+;(define echothread (thread echo-midi-events))