GENMIDI.OP2 is a sound bank file used by players based on DMX sound library to play MIDI files with General MIDI instruments using OPL2 sound chip (which was commonly installed on popular AdLib and Sound Blaster sound cards).
Major users of DMX sound library include:
This page hosts a formal specification of GENMIDI.OP2 OPL2 sound bank using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for JavaScript generated by Kaitai Struct depends on the JavaScript runtime library. You have to install it before you can parse data.
The JavaScript runtime library is available at npm:
npm install kaitai-structSee the usage examples in the JavaScript notes.
Parse structure from an ArrayBuffer:
var arrayBuffer = ...;
var data = new GenmidiOp2(new KaitaiStream(arrayBuffer));
After that, one can get various attributes from the structure by accessing fields or properties like:
data.magic // => get magic
// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
(function (root, factory) {
if (typeof define === 'function' && define.amd) {
define(['kaitai-struct/KaitaiStream'], factory);
} else if (typeof module === 'object' && module.exports) {
module.exports = factory(require('kaitai-struct/KaitaiStream'));
} else {
root.GenmidiOp2 = factory(root.KaitaiStream);
}
}(typeof self !== 'undefined' ? self : this, function (KaitaiStream) {
/**
* GENMIDI.OP2 is a sound bank file used by players based on DMX sound
* library to play MIDI files with General MIDI instruments using OPL2
* sound chip (which was commonly installed on popular AdLib and Sound
* Blaster sound cards).
*
* Major users of DMX sound library include:
*
* * Original Doom game engine (and games based on it: Heretic, Hexen, Strife, Chex Quest)
* * Raptor: Call of the Shadows
* @see {@link http://www.fit.vutbr.cz/~arnost/muslib/op2_form.zip|Source}
* @see {@link https://doom.fandom.com/wiki/GENMIDI|Source}
* @see {@link https://moddingwiki.shikadi.net/wiki/OP2_Bank_Format|Source}
*/
var GenmidiOp2 = (function() {
function GenmidiOp2(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root || this;
this._read();
}
GenmidiOp2.prototype._read = function() {
this.magic = this._io.readBytes(8);
if (!((KaitaiStream.byteArrayCompare(this.magic, [35, 79, 80, 76, 95, 73, 73, 35]) == 0))) {
throw new KaitaiStream.ValidationNotEqualError([35, 79, 80, 76, 95, 73, 73, 35], this.magic, this._io, "/seq/0");
}
this.instruments = [];
for (var i = 0; i < 175; i++) {
this.instruments.push(new InstrumentEntry(this._io, this, this._root));
}
this.instrumentNames = [];
for (var i = 0; i < 175; i++) {
this.instrumentNames.push(KaitaiStream.bytesToStr(KaitaiStream.bytesTerminate(KaitaiStream.bytesStripRight(this._io.readBytes(32), 0), 0, false), "ASCII"));
}
}
var InstrumentEntry = GenmidiOp2.InstrumentEntry = (function() {
function InstrumentEntry(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root || this;
this._read();
}
InstrumentEntry.prototype._read = function() {
this.flags = this._io.readU2le();
this.finetune = this._io.readU1();
this.note = this._io.readU1();
this.instruments = [];
for (var i = 0; i < 2; i++) {
this.instruments.push(new Instrument(this._io, this, this._root));
}
}
/**
* MIDI note for fixed instruments, 0 otherwise
*/
return InstrumentEntry;
})();
var Instrument = GenmidiOp2.Instrument = (function() {
function Instrument(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root || this;
this._read();
}
Instrument.prototype._read = function() {
this.op1 = new OpSettings(this._io, this, this._root);
this.feedback = this._io.readU1();
this.op2 = new OpSettings(this._io, this, this._root);
this.unused = this._io.readU1();
this.baseNote = this._io.readS2le();
}
/**
* Feedback/AM-FM (both operators)
*/
/**
* Base note offset
*/
return Instrument;
})();
/**
* OPL2 settings for one operator (carrier or modulator)
*/
var OpSettings = GenmidiOp2.OpSettings = (function() {
function OpSettings(_io, _parent, _root) {
this._io = _io;
this._parent = _parent;
this._root = _root || this;
this._read();
}
OpSettings.prototype._read = function() {
this.tremVibr = this._io.readU1();
this.attDec = this._io.readU1();
this.sustRel = this._io.readU1();
this.wave = this._io.readU1();
this.scale = this._io.readU1();
this.level = this._io.readU1();
}
/**
* Tremolo/vibrato/sustain/KSR/multi
*/
/**
* Attack rate/decay rate
*/
/**
* Sustain level/release rate
*/
/**
* Waveform select
*/
/**
* Key scale level
*/
/**
* Output level
*/
return OpSettings;
})();
return GenmidiOp2;
})();
return GenmidiOp2;
}));