Guile-OSC: Open Sound Control for Guile Scheme

Guile-OSC is a Guile wrapper for liblo, enabling Open Sound Control clients and servers to be implemented from Scheme.

Getting started

You will need the development files for Guile and liblo installed, as well as Meson. Then:

$ git clone https://github.com/taw10/guile-osc.git guile-osc
$ cd guile-osc
$ meson setup build
$ meson compile -C build
$ meson install -C build

Then, to receive OSC messages from within a Guile program:

(use-modules (open-sound-control server-thread))

(define osc-server (make-osc-server-thread "osc.udp://:7770"))

(add-osc-method osc-server
                "/my/osc/method"   ;; Method name
                "fi"               ;; Argument types (see liblo manual)
                (lambda (float-arg int-arg)
                   (do-something ...)))

(add-osc-method osc-server
                "/my/other/method"   ;; Method name
                ""                   ;; No arguments
                (lambda ()
                   (do-stuff ...)))

To define a wildcard method, which matches everything, use add-osc-wildcard instead of add-osc-method, leave the method name out but keep everything else.

If the separate server thread doesn't work in your application, there's also a blocking server option:

(use-modules (open-sound-control server))

(define s (make-osc-server "osc.udp://:7770"))

(add-osc-method s ....)

(osc-recv s)  ;; Blocks for 1 second, or until a message is received

You can even have multiple blocking servers at once: (osc-recv server1 server2).

To send messages (with parameters):

(use-modules (open-sound-control client))

(define osc-send-addr (make-osc-address "osc.udp://localhost:7771"))

(osc-send osc-send-addr "/their/osc/method" 1 2 4)
(osc-send osc-send-addr "/their/other/method" "string-arg")
(osc-send osc-send-addr "/yet/another/method" 0.3 "hello")

To send messages "from" a particular server, e.g. to communicate bidirectionally via a TCP connection, use osc-send-from. For example:

(define srv (make-osc-server "osc.tcp://:8000"))
(define dst (make-osc-address "osc.tcp://192.168.178.35:8000"))
(osc-send-from dst srv "/method/name" 1 2 3)

Examples

• examples/eos-x1k2.scm is the script I use, in conjunction with x1k2-midi-osc-alsa, to connect a USB MIDI control surface to Eos.

• examples/ma3-x1k2.scm is something similar, but for GrandMA3.

Licence

LGPL 2.1 (or later), the same as liblo itself.