midi2sc 0.1

Control SuperCollider Synths with MIDI

Installation

You can install midi2sc with easy_install:

$ easy_install midi2sc

However, you also need to install pkaudio and its dependencies.

Usage

midi2sc allows you to assign MIDI controllers to SuperCollider SynthDefs.

Configuration

An example configuration:

[SOSkick]
midi_channel = 01
001 = amp_mul=            AbsoluteControl(min=0.0, max=1.27, start_vel=100.0)
106 = mod_freq=           IDC(min=2.0, max=20.0, steps=50, value=2.0)
107 = mod_index=          IDC(min=2.0, max=20.0, steps=50, value=2.0)
108 = beater_noise_level= IDC(min=2.0, max=20.0, steps=50, value=18.0)
109 = decay=              IDC(min=0.05, max=1.0, steps=70, value=0.3)
noteon_args = out=18

This configuration will create and assign 7 controls: one of type AbsoluteControl, four of type IDC (IncDecControl). The two controls implicitly created are a NoteOnControl and a NoteOffControl.

The 001 midi controller is usually the modulation wheel. Here it’s bound to the amp_mul parameter of an SOSkick SynthDef. min is the value sent to the SuperCollider Synth when the wheel is at its lowest position, max the value at its highest position.

The 106 midi controller is bound to an endless encoder that sends relative values between 01 to 64 for increment and 127 to 065 for decrement. There’s 50 steps between the min and max value. And the value at which we start is 2.0. This corresponds to what the M-Audio Axiom User Guide calls 2's Complement from 0 / Relative (2's Complement).

There’s also dedicated controls for pitch bend and after touch.

SuperCollider

This is how a SynthDef could look like that uses the configuration from before:

SynthDef("SOSkick", {
  arg out = 0, freq = 50, mod_freq = 6.5, mod_index = 19.5,
  decay = 0.1, amp = 0.8, beater_noise_level = 0.001, amp_mul = 1.0;
  var x;

  // do stuff...
  Out.ar(out, x);
});

Make sure you have your SuperCollider server up and SynthDefs loaded before you start midi2sc.

Starting midi2sc

On the command-line, midi2sc is run like this:

$ midi2sc

This assumes that you have a midi2sc.ini configuration file in the current working directory. You can also provide this filename as an option on the command-line. Refer to the built-in help for more options:

$ midi2sc --help

midi2sc will ask you for a MIDI port to bind to, and then it’ll start a GUI that shows sliders for all controls and finally drop you into an interactive shell with access to variables like dictionary of control handlers and the save_presets and load_presets functions. To save presets (values from all controllers) from a file on the Python shell and then load them again later, you write:

>>> save_presets('presets1.pickle', midi_in)
>>> # ... time passes
>>> load_presets('presets0.pickle', midi_in)

You can also load a new midi2sc.ini configuration:

>>> handlers.update(configure.read('midi2sc2.ini'))

Screenshot

The top left window is the midi2sc Python shell. Below is the midi2sc GUI with a column of sliders for each synth. On the right are QJackCtl connections and Seq24:

Development Status

midi2sc is somewhat mature, and I use it. At the same time it’s a big hack and probably not thread-safe.

Change Log

0.1 - 2009-06-30

• First release.