(c) 2021 Steven Jones

Pigiron is a fully configurable MIDI routing utility written in Go. It includes a MIDI file player and has a comprehensive OSC interface.

The primary Pigiron object is called an Operator. Each Operator has zero or more MIDI inputs and zero or more MIDI outputs. When an Operator receives a MIDI message, it determines if the message should be forwarded to its outputs. An Operator may also modify the message prior to re-sending it.

Version 0.2.0 replaces the original portmidi backend with gomidi. After approximately 6 weeks of practical use, it appears to be more stable. There are still timing issues with the MIDIPlayer. It is OK for auditioning MIDI files, but not quite there for production use.

The following Operators are currently available:

• ChannelFilter - filter events by MIDI channel.
• SingleChannelFilter - More efficient channel filter fir single channel filtering.
• Distributor - transmit events over several MIDI channels.
• MIDIInput - wrapper for MIDI input device.
• MIDIOutput - wrapper for MIDI output device.
• MIDIPlayer - MIDI file player.
• Monitor - print incoming MIDI messages.
• Transformer - manipulate MIDI data bytes.

There are three distinct ways to interact with Pigiron.

1. Remotely via OSC messages.
2. Manually enter commands at terminal prompt.
3. Load a batch file of commands.

The command syntax for these modes are nearly identical. The only difference is that the command 'foo' at the terminal prompt or in a batch file is entered directly, while as an OSC message it is prefixed with the application OSC id (by default /pig/).

    foo        command at terminal or in batch file.
    /pig/foo   as OSC message.

On startup Pigiron displays a command prompt (by default /pig: ). For a list of help topics enter

/pig: help topics

For a list of commands enter

/pig: q-commands

For details on how OSC messages are handled, enter

/pig: help OSC

In general commands which begin with 'q-' (for query) returns some information.

The resources/batch directory contains the batch file 'example' which illustrates several commands to set up a basic MIDI process. It is heavily annotated.

Pigiron has been compiled and tested on Linux.   For compilation on
Ubuntu 22.04 the following packages were required:

- build-essential
- librtmidi-dev
 
Golang dependencies are:

- go 1.16
- github.com/pelletier/go-toml
- github.com/rakyll/portmidi
- github.com/hypebeast/go-osc

Build Pigiron

In a terminal navigate into the Pigiron directory and enter

[pigiron]$ go build .

Install

Copy the generated pigiron executable to a location included on $HOME/$PATH, typical locations would be ~/.local/bin or ~.bin

Configuration Directory

• Linux : ~/.config/pigiron/
• Windows : To be determined.
• OSX : To be determined.

The structure within the .config/pigiron/ directory is:

 ~/.config/
     |
     +--pigiron/
          |
          +-- config.toml
          +-- log
          |
          +-- batch/
          |
          +-- resources/
                |
                +-- help/
                +-- testFiles/

Within .config/pigiron/ create the batch directory and either simlink or copy the resources directory from the Pigiron project. Pigiron can operate without the resources directory but help will not be available and some unit test will fail.

Pigiron has the following command line options:

--config filename    # Use alternate configuration file.
--batch filename     # Load named batch file.

In general filenames within Pigiron may be prefixed with one of two special characters.

'~/foo' names the file foo relative to the user's home directory.
'!/foo' names a file relative to the configuration directory.

Pigiron is strictly a terminal based, however due to it's OSC interface it should be relatively easy to write a GUI client app.