JScript/mml2smf3 - Sample is best!

開発環境	メモ帳
実行環境	Microsoft Windows 8.1 (64bit)

mml2smf3.js

// OpenTextFile
var ForReading = 1;
 
// SaveOptionsEnum
var adSaveCreateOverWrite = 2;
 
var scale = {A:9, B:11, C:0, D:2, E:4, F:5, G:7};	// 音階
 
// 外部変数
var timebase = 480;
var deflen = 4;
var octave = 4;
var rest = 0;
var st;		// ストリーム
var sharp = "";
var flat = "";
var trk = new Array();
var trkno = 0;
var seqno = 0;
var atick = 0;	// absolute tick
 
WScript.Quit(main());
 
//==============================================================================
function main()
{
	// 引数処理
	var args = WScript.Arguments;
	if (args.length != 1) {
		WScript.Echo("usage: cscript mml2smf2.js mmlfile");
		return 1;
	}
	var path_in = args(0);
 
	// パス名処理
	var fso = WScript.CreateObject("Scripting.FileSystemObject");
	path_in = fso.GetAbsolutePathName(path_in);
	var dir = fso.GetParentFolderName(path_in);
	var fnm = fso.GetBaseName(path_in);
	var path_out = dir + "\\" + fnm + ".mid";
 
	// 入力ファイルのオープン
	var fi = fso.OpenTextFile(path_in, ForReading);	// ASCII
 
	trk[trkno] = new Array();
 
	while (! fi.AtEndOfStream) {
		var line = fi.ReadLine();
 
		ParseLine:
		for (var c = 0; c < line.length; ) {
			var cmd = line.substr(c++, 1).toUpperCase();
			var param = line.substr(c);
			switch (cmd) {
			case "\t": case " ": case "|":
				break;
			case "%":
				SeqData(rest, new Array(0xff, 0x2f, 0));
				rest = 0;
				trk[++trkno] = new Array();
				seqno = 0;
				atick = 0;
				break;
			case "'":
				break ParseLine;
			case "<":
				octave--;
				break;
			case ">":
				octave++;
				break;
			case "A": case "B": case "C": case "D": case "E": case "F": case "G":
				c += Note(cmd, param);
				break;
			case "K":	// 調号 key signature
				var p = param.match(/^([#+\-])([A-G]+)/i);
				c += p[0].length;
				if (p[1] == "-") {
					flat = p[2].toUpperCase();
				} else {
					sharp = p[2].toUpperCase();
				}
				break;
			case "L":
				var p = param.match(/^(\d*)/);
				c += p[0].length;
				deflen = parseInt(p[1]);
				break;
			case "O":
				var p = param.match(/^(\d*)/);
				c += p[0].length;
				octave = parseInt(p[1]);
				break;
			case "R":
				c += Rest(param);
				break;
			case "T":
				var p = param.match(/^(\d*)/);
				c += p[0].length;
				var tempo = parseInt(p[1]);
				var usec = 60000000 / tempo;	// 4分音符のマイクロ秒数
				SeqData(rest, new Array(0xff, 0x51, 3,
					(usec>>16) & 0xff, (usec>>8) & 0xff, usec & 0xff));
				rest = 0;
				break;
			}
		}
	}
	fi.Close();
 
	// トラック終了
	SeqData(rest, new Array(0xff, 0x2f, 0));
 
	//-----------------------------------------------------------------------------
	// ストリームのオープン
	st = WScript.CreateObject("ADODB.Stream");
	st.Charset = "iso-8859-1";
	st.Open();
 
	// ヘッダチャンク
	WriteBE(4, 0x4d546864);	// MThd
	WriteBE(4, 6);		// データ長
	WriteBE(2, 1);		// フォーマットタイプ
	WriteBE(2, trkno + 1);	// トラック数
	WriteBE(2, timebase);	// タイムベース
 
	for (var tr in trk) {
		// トラックチャンク
		WriteBE(4, 0x4d54726b);	// MTrk
		WriteBE(4, 0);		// データ長（仮）
		var datalen = 0;
		var prevtick = 0;
		seq = trk[tr];
		for (var s in seq) {
			var data = seq[s];
			var t = data.tick - prevtick;
			prevtick = data.tick;
			// 可変長tick
			var v = ((t&0xfe00000)<<3)|((t&0x1fc000)<<2)|((t&0x3f80)<<1)|(t&0x7f)|0x80808000;
			for (var n = 3; 0 <= n; n--) {
				var b = (v >> (8 * n)) & 0xff;
				if (b != 0x80) {
					st.WriteText(String.fromCharCode(b));
					datalen++;
				}
			}
			for (var d = 0; d < data.length; d++) {
				st.WriteText(String.fromCharCode(data[d]));
				datalen++;
			}
		}
		var pos = st.Position;
		st.Position = pos - datalen - 4;
		WriteBE(4, datalen);	// データ長
		st.Position = pos;
	}
 
	// ストリームをファイルに保存
	st.SaveToFile(path_out, adSaveCreateOverWrite);
	st.Close();
 
	// 再生
	var WshShell = WScript.CreateObject("WScript.Shell");
	WshShell.Run(path_out);
 
	return 0;
}
 
function WriteBE(count, value)
{
	for (var n = count - 1; 0 <= n; n--) {
		st.WriteText(String.fromCharCode( (value >> (8 * n)) & 0xff ));
	}
}
 
function SeqData(tick, data)
{
	data.tick = (atick += tick);
	trk[trkno][seqno++] = data;
}
 
// 音符処理
function Note(cmd, param)
{
	var p = param.match(/^(\/?)([#+]*)(\-*)(\d*)(\.*)(&?)/);
 
	// 臨時記号 accidental
	var acci;
	if (p[1]) {
		acci = 0;
	} else {
		acci = p[2].length - p[3].length;
		if (acci == 0) {
			if (sharp.indexOf(cmd) != -1) acci = 1;
			if (flat.indexOf(cmd) != -1) acci = -1;
		}
	}
	var note = (octave + 1) * 12 + scale[cmd] + acci;
 
	var value = (p[4] == "") ? deflen : parseInt(p[4]);
	var dot = p[5].length;
 
	var tick = timebase * 4 / value;
	tick += tick * ((1<<dot) - 1) / (1<<dot);
	var gate = (p[6]) ? tick : tick * 7 / 8;
 
	// タイ処理
	var seq = trk[trkno];
	if (rest == 0 && 0 < seqno && seq[seqno-1][0] == 0x80 && seq[seqno-1][1] == note) {
		seq[seqno-1].tick = (atick += gate);
	} else {
		SeqData(rest, new Array(0x90 | trkno, note, 0x70));
		SeqData(gate, new Array(0x80 | trkno, note, 0x00));
	}
 
	rest = tick - gate;
	return p[0].length;
}
 
// 休符処理
function Rest(param)
{
	var p = param.match(/^(\d*)(\.*)/);
	var value = (p[1] == "") ? deflen : parseInt(p[1]);
	var dot = p[2].length;
	var tick = timebase * 4 / value;
	tick += tick * ((1<<dot) - 1) / (1<<dot);
	rest += tick;
	return p[0].length;
}
 

もろびとこぞりて.txt

t110
k+fc
 
o5dc8.<b16 a.g8 fe d.a8 b.b8
o5c.c8 t55d.t110d8 d8c8<b8a8 a8.g16f8>d8 d8c8<b8a8
a8.g16f8f8 f8f8f8f16g16 a.g16f16 e8e8e8e16f16
g.f16e16 d8&>d<b8 a8.g16f8g8 fe d2
 
%
o4fa8.g16 f.e8 dc d.a8 g.g8
e.e8 f.f8 f8a8g8f8 f8.e16d8f8 f8a8g8f8
f8.e16d8d8 d8d8d8d16e16 f.e16d16 c8c8c8c16d16
e.d16c16 d8&fg8 f8.e16d8e8 dc d2