0x07dc · June 8, 2014 11:51 · Oct 30, 2012 · Oct 30, 2012
diff --git a/makewav.js b/makewav.js
@@ -1,4 +1,4 @@
-Wav = function(opt_params){
+var Wav = function(opt_params){
 
 	/**
 	 * @private

diff --git a/makewav.js b/makewav.js
@@ -0,0 +1,138 @@
+Wav = function(opt_params){
+
+	/**
+	 * @private
+	 */
+	this._sampleRate = opt_params && opt_params.sampleRate ? opt_params.sampleRate : 44100;
+
+	/**
+	 * @private
+	 */
+	this._channels = opt_params && opt_params.channels ? opt_params.channels : 2;  
+
+	/**
+	 * @private
+	 */
+	this._eof = true;
+
+	/**
+	 * @private
+	 */
+	this._bufferNeedle = 0;
+
+	/**
+	 * @private
+	 */
+	this._buffer;
+
+};
+
+Wav.prototype.setBuffer = function(buffer){
+	this._buffer = this.getWavInt16Array(buffer);
+	this._bufferNeedle = 0;
+	this._internalBuffer = '';
+	this._hasOutputHeader = false;
+	this._eof = false;
+};
+
+Wav.prototype.getBuffer = function(len){
+
+	var rt;
+	if( this._bufferNeedle + len >= this._buffer.length ){
+		rt = new Int16Array(this._buffer.length - this._bufferNeedle);
+		this._eof = true;
+	}
+	else {
+		rt = new Int16Array(len);
+	}
+
+	for(var i=0; i<rt.length; i++){
+		rt[i] = this._buffer[i+this._bufferNeedle];
+	}
+	this._bufferNeedle += rt.length;
+
+	return  rt.buffer;
+
+
+};
+
+Wav.prototype.eof = function(){
+	return this._eof;
+};
+
+Wav.prototype.getWavInt16Array = function(buffer){
+
+	var intBuffer = new Int16Array(buffer.length + 23), tmp;
+
+	intBuffer[0] = 0x4952; // "RI"
+	intBuffer[1] = 0x4646; // "FF"
+
+	intBuffer[2] = (2*buffer.length + 15) & 0x0000ffff; // RIFF size
+	intBuffer[3] = ((2*buffer.length + 15) & 0xffff0000) >> 16; // RIFF size
+
+	intBuffer[4] = 0x4157; // "WA"
+	intBuffer[5] = 0x4556; // "VE"
+
+	intBuffer[6] = 0x6d66; // "fm"
+	intBuffer[7] = 0x2074; // "t "
+
+	intBuffer[8] = 0x0012; // fmt chunksize: 18
+	intBuffer[9] = 0x0000; //
+
+	intBuffer[10] = 0x0001; // format tag : 1 
+	intBuffer[11] = this._channels; // channels: 2
+
+	intBuffer[12] = this._sampleRate & 0x0000ffff; // sample per sec
+	intBuffer[13] = (this._sampleRate & 0xffff0000) >> 16; // sample per sec
+
+	intBuffer[14] = (2*this._channels*this._sampleRate) & 0x0000ffff; // byte per sec
+	intBuffer[15] = ((2*this._channels*this._sampleRate) & 0xffff0000) >> 16; // byte per sec
+
+	intBuffer[16] = 0x0004; // block align
+	intBuffer[17] = 0x0010; // bit per sample
+	intBuffer[18] = 0x0000; // cb size
+	intBuffer[19] = 0x6164; // "da"
+	intBuffer[20] = 0x6174; // "ta"
+	intBuffer[21] = (2*buffer.length) & 0x0000ffff; // data size[byte]
+	intBuffer[22] = ((2*buffer.length) & 0xffff0000) >> 16; // data size[byte]	
+
+	for (var i = 0; i < buffer.length; i++) {
+		tmp = buffer[i];
+		if (tmp >= 1) {
+			intBuffer[i+23] = (1 << 15) - 1;
+		}
+		else if (tmp <= -1) {
+			intBuffer[i+23] = -(1 << 15);
+		}
+		else {
+			intBuffer[i+23] = Math.round(tmp * (1 << 15));
+		}
+	}
+
+	return intBuffer;
+};
+var i=0, vol=0.1,
+    sampleRate = 48000, 
+    wav = new Wav({sampleRate: sampleRate, channels: 1}),
+    buffer = new Float32Array(sampleRate);
+
+while(i<sampleRate){
+    if( parseInt(i/100) % 2 ){
+        buffer[i] = -vol;
+    }
+    else {
+        buffer[i] = vol;
+    }
+    i++;
+}
+wav.setBuffer(buffer);
+
+var srclist = [];
+while( !wav.eof() ){
+    srclist.push(wav.getBuffer(1000));
+}
+
+var b = new Blob(srclist, {type:'audio/wav'});
+var URLObject = window.webkitURL || window.URL;
+var url = URLObject.createObjectURL(b);
+document.write("<a href='"+url+"'>play</a>");