implemented PitchShifter.js

w0lramD · Jun 16, 2015 · 6eef432 · 6eef432
1 parent 6cb8e8a
commit 6eef432
Show file tree

Hide file tree

Showing 11 changed files with 133 additions and 81 deletions.
diff --git a/Gruntfile.js b/Gruntfile.js
@@ -9,7 +9,7 @@ module.exports = function(grunt) {
       },
       dist: {
         // the files to concatenate
-        src: ['src/*.js', 'soundtouch.js'],
+        src: ['src/buffer.js','src/core.js','src/filter.js','src/pipe.js','src/rate-transposer.js','src/soundtouch.js','src/stretch.js','src/pitchshifter.js'],
         // the location of the resulting JS file
         dest: 'tmp/soundtouch.concat.js'
       }

diff --git a/example/example.html b/example/example.html
@@ -1,14 +1,24 @@
-<script src="http://documentcloud.github.com/underscore/underscore.js"></script>
-<script src="../soundtouch.min.js"></script>
-<script src="example.js"></script>
-<script>
-var count = 0;
+<!DOCTYPE HTML>
+<html>
+<head>
+	<title>soundtouch.js demo</title>
+	<script src="../soundtouch.min.js"></script>
+	<style type="text/css">
+		body {
+			background: grey;
+			line-height: 30px;
+		}
 
-function increment() {
-    console.log('increment')
-    if (count++ > 100) {
-        pause();
-        throw Error('whoa');
-    }
-}
-</script>
+		input, button {
+			display:block;
+		}
+	</style>
+</head>
+<body>
+	<button onclick="play()">Play</button>
+	<button onclick="pause()">Pause</button>
+	Rate: <input type="range" autofocus="true" min="0.1" max="4.0" name="tempoSlider" defaultValue="1.0" id="tempoSlider" step="0.01">
+	Pitch: <input type="range" autofocus="true" min="0.1" max="2.0" name="pitchSlider" defaultValue="1.0" id="pitchSlider" step="0.01">
+</body>
+<script src="example.js"></script>
+</html>
diff --git a/example/example.js b/example/example.js
@@ -1,75 +1,47 @@
-var t = new RateTransposer(true);
-var s = new Stretch(true);
-//s.tempo = .5;
-t.rate = 2;
-var context = new webkitAudioContext();
-
-var buffer;
-
-loadSample = function(url) {
-    var request = new XMLHttpRequest();
-    request.open('GET', url, true);
-    request.responseType = 'arraybuffer';
+//AC polyfill
+window.AudioContext = window.AudioContext ||
+  window.webkitAudioContext ||
+  window.mozAudioContext ||
+  window.oAudioContext ||
+  window.msAudioContext
 
-    request.onload = function() {
-        console.log('url loaded');
-        createBuffer(request.response);
-    }
-
-    console.log('reading url');
-    request.send();
-}
+var context = new webkitAudioContext();
 
-function createBuffer(arrayBuffer) {
-    offset = 0;
-    startTime = 0;
-    var start = new Date();
-    // NOTE the second parameter is required, or a TypeError is thrown
-    buffer = context.createBuffer(arrayBuffer, false);
-    console.log('loaded audio in ' + (new Date() - start));
+var pitchshifter, buffer;
+
+//GET AUDIO FILE
+var request = new XMLHttpRequest();
+request.open('GET', 'sound1.wav', true);
+request.responseType = 'arraybuffer';
+
+request.onload = function() {
+    console.log('url loaded');
+    context.decodeAudioData(request.response, function(buf) {
+        //we now have the audio data
+        buffer = buf;
+        console.log('decoded');
+        pitchshifter = new PitchShifter(context, buffer, 1024);
+        pitchshifter.tempo = 0.75;
+    });
 }
 
-//loadSample('badromance.mp3')
-loadSample('track.mp3')
-
-var BUFFER_SIZE = 1024;
-
-var node = context.createScriptProcessor(BUFFER_SIZE, 2, 2);
-
-var samples = new Float32Array(BUFFER_SIZE * 2);
-
-node.onaudioprocess = function (e) {
-    var l = e.outputBuffer.getChannelData(0);
-    var r = e.outputBuffer.getChannelData(1);
-    var framesExtracted = f.extract(samples, BUFFER_SIZE);
-    if (framesExtracted == 0) {
-        pause();
-    }
-    for (var i = 0; i < framesExtracted; i++) {
-        l[i] = samples[i * 2];
-        r[i] = samples[i * 2 + 1];
-    }
-};
+console.log('reading url');
+request.send();
 
+//PLAYBACK
 function play() {
-    node.connect(context.destination);
+    pitchshifter.connect(context.destination);
+    console.log("play")
 }
 
 function pause() {
-    node.disconnect();
+    pitchshifter.disconnect();
 }
 
-var source = {
-    extract: function (target, numFrames, position) {
-        var l = buffer.getChannelData(0);
-        var r = buffer.getChannelData(1);
-        for (var i = 0; i < numFrames; i++) {
-            target[i * 2] = l[i + position];
-            target[i * 2 + 1] = r[i + position];
-        }
-        return Math.min(numFrames, l.length - position);
-    }
-};
-
+document.getElementById('tempoSlider').addEventListener('input', function(){
+    pitchshifter.tempo = this.value;
+});
 
-f = new SimpleFilter(source, s);
+document.getElementById('pitchSlider').addEventListener('input', function(){
+    pitchshifter.pitch = this.value;
+});
diff --git a/example/sound1.wav b/example/sound1.wav
diff --git a/index.js b/index.js
@@ -0,0 +1,7 @@
+var core = require('./src/core')
+var buffer = require('./src/buffer')
+var filter = require('./src/filter')
+var pipe = require('./src/pipe')
+var rateTransposer = require('./src/rate-transposer')
+var soundtouch = require('./src/soundtouch')
+var stretch = require('./src/stretch')
diff --git a/package.json b/package.json
@@ -2,7 +2,7 @@
   "name": "soundtouch-js",
   "version": "1.0.0",
   "description": "Javascript audio time-stretching and pitch-shifting library",
-  "main": "soundtouch.js",
+  "main": "index.js",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
   },

diff --git a/soundtouch.min.js b/soundtouch.min.js
diff --git a/src/buffer.js b/src/buffer.js
@@ -122,4 +122,4 @@ FifoSampleBuffer.prototype = {
             this._position = 0;
         }
     }
-};
+};
diff --git a/src/pitchshifter.js b/src/pitchshifter.js
@@ -0,0 +1,25 @@
+function PitchShifter (ctx, buffer, bufSize) {
+	this._st = new SoundTouch();
+    this._f = new SimpleFilter(new WebAudioBufferSource(buffer), this._st, bufSize);
+    this._node = getWebAudioNode(ctx, this._f);
+}
+
+PitchShifter.prototype.connect = function(toNode) {
+	this._node.connect(toNode);
+}
+
+PitchShifter.prototype.disconnect = function(toNode) {
+	this._node.disconnect();
+}
+
+extend(PitchShifter.prototype, {
+	set pitch(p) {
+		this._st.pitch = p;
+	},
+	set rate(r) {
+		this._st.rate = r;
+	},
+	set tempo(t) {
+		this._st.tempo = t;
+	}
+});
diff --git a/src/rate-transposer.js b/src/rate-transposer.js
@@ -20,7 +20,9 @@
 
 function RateTransposer(createBuffers) {
     AbstractFifoSamplePipe.call(this, createBuffers);
-    this._reset();
+    this.slopeCount = 0;
+    this.prevSampleL = 0;
+    this.prevSampleR = 0;
     this.rate = 1;
 }
 

diff --git a/soundtouch.js → src/soundtouch.js b/soundtouch.js → src/soundtouch.js
@@ -98,6 +98,7 @@ extend(SoundTouch.prototype, {
     },
 
     _calculateEffectiveRateAndTempo: function () {
+        console.log("calculating");
         var previousTempo = this._tempo;
         var previousRate = this._rate;
 
@@ -142,3 +143,38 @@ extend(SoundTouch.prototype, {
         }
     }
 });
+
+function WebAudioBufferSource(buffer) {
+    this.buffer = buffer;
+}
+WebAudioBufferSource.prototype = {
+    extract: function(target, numFrames, position) {
+        var l = this.buffer.getChannelData(0);
+        var r;
+        if (buffer.numberOfChannels > 1) r = this.buffer.getChannelData(1);
+        for (var i = 0; i < numFrames; i++) {
+            target[i * 2] = l[i + position];
+            if (buffer.numberOfChannels > 1) target[i * 2 + 1] = r[i + position];
+        }
+        return Math.min(numFrames, l.length - position);
+    }
+};
+
+function getWebAudioNode(context, filter, bufSize) {
+    var BUFFER_SIZE = bufSize || 1024;
+    var node = context.createScriptProcessor ? context.createScriptProcessor(BUFFER_SIZE, 2, 2) : context.createJavascriptNode(BUFFER_SIZE, 2, 2),
+        samples = new Float32Array(BUFFER_SIZE * 2);
+    node.onaudioprocess = function(e) {
+        var l = e.outputBuffer.getChannelData(0),
+            r = e.outputBuffer.getChannelData(1);
+        var framesExtracted = filter.extract(samples, BUFFER_SIZE);
+        if (framesExtracted === 0) {
+            node.disconnect(); // Pause.
+        }
+        for (var i = 0; i < framesExtracted; i++) {
+            l[i] = samples[i * 2];
+            r[i] = samples[i * 2 + 1];
+        }
+    };
+    return node;
+}
-Original file line number
+Diff line change
@@ Expand Up / @@ -122,4 +122,4 @@ FifoSampleBuffer.prototype = { @@
                 this._position = 0;
             }
         }
-    };
+    };