I needed to decode midi data for FirmataPi. I learned a lot from node-firmata, Essentials of the MIDI protocol and Control Systems for Live Entertainment which is a great book, and this nice little C library Miby: MIDI Byte-stream Parser based off the MIDI 1.0 spec.
The midi-parser library is a node event emitter. You write midi commands in buffers and it emits
sysex commands as events. We avoid releasing zalgo by always emitting events immediately.
The SysEx commands are unwrapped of their header and footer bytes and provided on the
sysex event with the command, and data. Since any multibyte data (eg strings) or values over 127 need to be "14 bit encoded". The class methods
encodeString are available to assist.
The Midi command are emitted on the
midi event with command, channel (or null if N/A), and an array of data bytes.
This is public domain work. Feel free to use it, abuse it, complain about performance, bugs, etc. Patches that add core parser or extensibility features are very welcome. The libraries intention is to decode the messages and make them available to another program, not to decode the meanings of these messages for humans. All Patches are welcome with that in mind.