added encodec type

.eslintrc.json

@@ -1,33 +0,0 @@
-{
-  "env": {
-    "browser": true,
-    "es6": true
-  },
-  "globals": {
-    "ENV": true
-  },
-  "extends": "eslint:recommended",
-  "parserOptions": {
-    "sourceType": "module"
-  },
-  "rules": {
-    "indent": [
-        "error",
-        4,
-        { "SwitchCase": 1 }
-    ],
-    "no-unused-vars": "off",
-    "linebreak-style": [
-      "error",
-      "unix"
-    ],
-    "quotes": [
-      "error",
-      "single"
-    ],
-    "semi": [
-      "error",
-      "always"
-    ]
-  }
-}

src/pcm-player.js

@@ -1,11 +1,46 @@
-function PCMPlayer(channels, sampleRate) {
+function PCMPlayer(option) {
+    this.init(option);
+}
 
+PCMPlayer.prototype.init = function(option) {
+    var default = {
+        encoding: '16bitInt',
+        channels: 1,
+        sampleRate: 8000,
+        flushingTime: 200
+    };
+    this.option = Object.assign({}, default, option);
     this.samples = new Float32Array();
-    this.flushingTime = 200;
-    this.channels = channels;
-    this.sampleRate = sampleRate;
+    this.flush = this.flush.bind(this);
+    this.interval = setInterval(this.flush, this.flushingTime);
+    this.maxValue = this.getMaxValue();
+    this.typedArray = this.getTypedArray();
+    this.createContext();
+};
+
+PCMPlayer.prototype.getMaxValue = function () {
+    var encodings = {
+        '8bitInt': 128,
+        '16bitInt': 32768,
+        '32bitInt': 2147483648,
+        '32bitFloat': 1
+    }
 
-    this.createContext = function() {
+    return encodings[this.option.encoding] ? encodings[this.option.encoding] : encodings['16bitInt'];
+};
+
+PCMPlayer.prototype.getTypedArray = function () {
+    var typedArrays = {
+        '8bitInt': 'Int8Array',
+        '16bitInt': 'Int16Array',
+        '32bitInt': 'Int32Array',
+        '32bitFloat': 'Float32Array'
+    }
+
+    return typedArrays[this.option.encoding] ? typedArrays[this.option.encoding] : typedArrays['16bitInt'];
+};
+
+PCMPlayer.prototype.createContext = function() {
     this.audioCtx = new (window.AudioContext || window.webkitAudioContext)();
     this.gainNode = this.audioCtx.createGain();
     this.gainNode.gain.value = 1;
@@ -13,31 +48,53 @@ function PCMPlayer(channels, sampleRate) {
     this.startTime = this.audioCtx.currentTime;
 };
 
-    this.stopFlushing = function() {
-        if (this.interval) {
-            clearInterval(this.interval);
-        }
+PCMPlayer.prototype.isTypedArray = function(data) {
+    return (data.byteLength && data.buffer && data.buffer.constructor == ArrayBuffer);
 };
 
-    this.feed = function(data) {
-        let tmp = new Float32Array(this.samples.length + data.length);
+PCMPlayer.prototype.feed = function(data) {
+    if (!this.isTypedArray(isTypedArray)) return;
+    data = this.getFormatedValue(data);
+    var tmp = new Float32Array(this.samples.length + data.length);
     tmp.set(this.samples, 0);
     tmp.set(data, this.samples.length);
     this.samples = tmp;
 };
 
-    this.flush = function() {
-        if (!this.channels || !this.sampleRate || !this.samples.length) return;
-        let bufferSource = this.audioCtx.createBufferSource(),
+PCMPlayer.prototype.getFormatedValue = function(data) {
+    var data = new this.typedArray(data.buffer),
+        float32 = new Float32Array(data.length),
+        i;
+
+    for (i = 0; i < data.length; i++) {
+        float32[i] = data[i] / this.maxValue;
+    }
+    return float32;
+};
+
+PCMPlayer.prototype.volume = function(volume) {
+    this.gainNode.gain.value = volume;
+};
+
+PCMPlayer.prototype.destroy = function() {
+    if (this.interval) {
+        clearInterval(this.interval);
+    }
+    this.samples = null;
+};
+
+PCMPlayer.prototype.flush = function() {
+    if (!this.samples.length) return;
+    var bufferSource = this.audioCtx.createBufferSource(),
         length = this.samples.length,
-            audioBuffer = this.audioCtx.createBuffer(this.channels, length, this.sampleRate),
+        audioBuffer = this.audioCtx.createBuffer(this.option.channels, length, this.option.sampleRate),
         audioData,
         channel,
         offset,
         i,
         decrement = 50;
 
-        for (channel = 0; channel < this.channels; channel++) {
+    for (channel = 0; channel < this.option.channels; channel++) {
         audioData = audioBuffer.getChannelData(channel);
         offset = channel;
         for (i = 0; i < length; i++) {
@@ -50,7 +107,7 @@ function PCMPlayer(channels, sampleRate) {
             if (i >= (length - 51)) {
                 audioData[i] =  (audioData[i] * decrement--) / 50;
             }
-                offset += this.channels;
+            offset += this.option.channels;
         }
     }
     
@@ -63,9 +120,3 @@ function PCMPlayer(channels, sampleRate) {
     this.startTime += audioBuffer.duration;
     this.samples = new Float32Array();
 };
-
-    /* initiate start flushing */
-    this.flush = this.flush.bind(this);
-    this.createContext();
-    this.interval = setInterval(this.flush, this.flushingTime);
-}