JScript/mml2smf2.js - Sample is best!

実行環境	Microsoft Windows 8.1 (64bit)

mml2smf2.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 datalen;	// データ長
var st;		// ストリーム
var sharp = "";
var flat = "";
var seq = new Array();
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
 
	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 "'":
				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, 0);		// フォーマットタイプ
	WriteBE(2, 1);		// トラック数
	WriteBE(2, timebase);	// タイムベース
 
	// トラックチャンク
	WriteBE(4, 0x4d54726b);	// MTrk
	WriteBE(4, 0);		// データ長（仮）
	datalen = 0;
 
	var prevtick = 0;
	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 += data.length;
	}
 
	st.Position -= datalen + 4;
	WriteBE(4, datalen);	// データ長
 
	// 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 ));
	}
	datalen += count;
}
 
function SeqData(tick, data)
{
	data.tick = (atick += tick);
	seq[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
	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, note, 0x70));
		SeqData(gate, new Array(0x80, 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;
}
 

トロイカ.txt

' トロイカ
' ロシア民謡
 
'Ch1
t130
k-bea
g8 | >c.c8c8c8<b/8>c8 | d.<b/8gr8g8 | >ec<ef8f8 |
g2.r8g8 | >c.d8e8d8c8<a16g16 | f.a8>cd8c8 |
o4 g.a8g8f8d8e8 | c2.g | >c.d8e8d8c8<a16g16 |
f.a8>cd8c8 | <g.a8g8f8d8e8 | c2.r8
 

浜辺の歌.txt

' 浜辺の歌
 
t72
k-b
c8 | cf16g16ag16f16 | g&d8fe16d16 | c&f8ag16f16 | g.&g8r8 |
c8 | cf16g16ag16f16 | g&d8fe16d16 | c&a8cg8 | f.&f8r8 |
o5 c8 | c<g8>c&<g+8 | >c.<a>d8 | d<b8fg8 | t60 >c.&c8r8 t72 |
o4 c8 | cf16g16a&g16&f16 | g&d8fe16d16 | ca8cg8 | f.&f8r8 |