JackoInit — Initializes Csound as a Jack client.


Plugin opcode in jacko. This opcode is part of the plugin repository and has to be installed separately. The plugin repository can be found here: https://github.com/csound/plugins

Initializes this instance of Csound as a Jack client. If the name of the Jack daemon is not specified, then its name is literally "default" (see https://manpages.debian.org/buster/jackd2/jackd.1.en.html) If you configure Jack to use a different name, then you need to specify that name in the JackoInit call.

Csound's sr must be equal to the Jack daemon's frames per second.

Csound's ksmps must be equal to the Jack daemon's frames per period.

Frames per period must not only (a) be a power of 2, but also (b) go evenly into the frames per second, e.g. 128 frames per period goes into 48000 frames per second 375 times, for a latency or MIDI time granularity of about 2.7 milliseconds (as good as or better than the absolute best human performers).

The order of processing of all signals that pass from Jack input ports, through Csound processing, and to Jack output ports, must be properly determined by sequence of instrument and opcode definition within Csound.


JackoInit ServerName, SclientName


SclientName -- The name of the Jack client; normally, should be "csound".

ServerName -- The name of the Jack daemon; normally, will be "default".

This opcode must be called once and only once in the orchestra header, and before any other Jack opcodes. If more than one instance of Csound is using the Jack opcodes at the same time, then each instance of Csound must use a different client name.

[Note] Note
works with an already running Jack daemon. Do not use -+rtaudio=jack in CsOptions


Here is an example of the JackoInit opcode. It uses the file JackoInit.csd.

Example 496. Example of the JackoInit opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.


sr  = 48000
ksmps = 128
nchnls  = 2
0dbfs   = 1

; by Menno Knevel - 2023

JackoInit "default", "csound"

instr 1


i 1 0 1

See also

Jacko Opcodes


By: Michael Gogins 2010