OPEN SOUND CONTROL - NETWORK COMMUNICATION

Open Sound Control (OSC) is a network protocol format for musical control data communication. A few of its advantages compared to MIDI are, that it's more accurate, quicker and much more flexible. With OSC you can easily send messages to other software independent if it's running on the same machine or over network. There is OSC support in software like PD, Max/Msp, Chuck or SuperCollider. A nice screencast of Andrés Cabrera shows communication between PD and Csound via OSC.¹ 

OSC messages contain an IP adress with port information and the data-package which will be send over network. In Csound, there are two opcodes, which provide access to network communication called OSCsend, OSClisten.

Example 08A01_osc.csd

<CsoundSynthesizer>
<CsOptions>
-o dac
</CsOptions>
<CsInstruments>
sr = 48000
ksmps = 32
nchnls = 2
0dbfs = 1

; localhost means communication on the same machine, otherwise you need
; an IP adress
#define IPADDRESS       # "localhost" #
#define S_PORT          # 47120 #
#define R_PORT          # 47120 #

turnon 1000  ; starts instrument 1000 immediately
turnon 1001  ; starts instrument 1001 immediately
        

instr 1000  ; this instrument sends OSC-values
        kValue1 randomh 0, 0.8, 4
        kNum randomh 0, 8, 8
        kMidiKey tab (int(kNum)), 2
        kOctave randomh 0, 7, 4
        kValue2 = cpsmidinn (kMidiKey*kOctave+33)
        kValue3 randomh 0.4, 1, 4
        Stext sprintf "%i", $S_PORT
        OSCsend   kValue1+kValue2, $IPADDRESS, $S_PORT, "/QuteCsound",
                  "fff", kValue1, kValue2, kValue3
endin


instr 1001  ; this instrument receives OSC-values       
        kValue1Received init 0.0
        kValue2Received init 0.0
        kValue3Received init 0.0
        Stext sprintf "%i", $R_PORT
        ihandle OSCinit $R_PORT
        kAction  OSClisten      ihandle, "/QuteCsound", "fff",
                 kValue1Received, kValue2Received, kValue3Received
                if (kAction == 1) then  
                        printk2 kValue2Received
                        printk2 kValue1Received
                        
                endif
        aSine poscil3 kValue1Received, kValue2Received, 1
        ; a bit reverbration
        aInVerb = aSine*kValue3Received
        aWetL, aWetR freeverb aInVerb, aInVerb, 0.4, 0.8
outs aWetL+aSine, aWetR+aSine
endin

</CsInstruments>
<CsScore>
f 1 0 1024 10 1
f 2 0 8 -2      0 2 4 7 9 11 0 2
e 3600
</CsScore>
</CsoundSynthesizer>
; example by Alex Hofmann (Mar. 2011)

1. As another example you can communicate via OSC between Csound and Grame's Inscore. Find the code at https://github.com/joachimheintz/cs_inscore and video tutorials at
   http://vimeo.com/54160283 (installation)
   http://vimeo.com/54160405 (examples) ^{^}