+var gModSound = {
+ activate: function() {
+ //gSounds.scan.play();
+ if (navigator.getUserMedia &&
+ (window.AudioContext || window.webkitAudioContext)) {
+ document.getElementById("soundunavail").style.display = "none";
+ document.getElementById("soundavail").style.display = "block";
+ navigator.getUserMedia({ audio: true },
+ function(aLocalMediaStream) {
+ gModSound.mAudio.stream = aLocalMediaStream;
+ gModSound.mAudio.context = new (window.AudioContext ||
+ window.webkitAudioContext)();
+ gModSound.mAudio.input =
+ gModSound.mAudio.context.createMediaStreamSource(gModSound.mAudio.stream);
+ // Could put a filter in between like in http://webaudioapi.com/samples/microphone/
+ gModSound.mDisplay.canvas = document.getElementById("soundcanvas");
+ gModSound.mDisplay.context = gModSound.mDisplay.canvas.getContext("2d");
+ gModSound.rebuildCanvas();
+ },
+ function(aError) {
+ document.getElementById("soundunavail").style.display = "block";
+ document.getElementById("soundavail").style.display = "none";
+ console.log(aError);
+ }
+ );
+ }
+ else {
+ document.getElementById("soundunavail").style.display = "block";
+ document.getElementById("soundavail").style.display = "none";
+ }
+ },
+ rebuildCanvas: function() {
+ if (gModSound.mDisplay.AFRequestID) {
+ window.cancelAnimationFrame(gModSound.mDisplay.AFRequestID);
+ gModSound.mDisplay.AFRequestID = 0;
+ }
+ gModSound.mDisplay.canvas.height =
+ document.getElementById("soundavail").clientHeight - 4;
+ gModSound.mDisplay.canvas.width =
+ document.getElementById("soundavail").clientWidth;
+ gModSound.mAudio.frequencySlices = (gModSound.mDisplay.canvas.width > 512) ?
+ 512 :
+ Math.pow(2, Math.floor(Math.log(gModSound.mDisplay.canvas.width) / Math.LN2));
+ //console.log("slices: " + gModSound.mAudio.frequencySlices);
+ gModSound.mAudio.analyzer = gModSound.mAudio.context.createAnalyser();
+ // Make the FFT four times as large as needed as the upper three quarters turn out to be useless.
+ gModSound.mAudio.analyzer.fftSize = gModSound.mAudio.frequencySlices * 4;
+ //console.log("FFT: " + gModSound.mAudio.analyzer.fftSize);
+ gModSound.mAudio.input.connect(gModSound.mAudio.analyzer);
+ gModSound.mDisplay.context.setTransform(1, 0, 0,
+ -(gModSound.mDisplay.canvas.height/256),
+ 0, gModSound.mDisplay.canvas.height);
+ gModSound.mDisplay.active = true;
+ gModSound.mDisplay.AFRequestID =
+ window.requestAnimationFrame(gModSound.paintAnalyzerFrame);
+ },
+ mAudio: {
+ frequencySlices: 32, // Must be a multiple of 2 (see AnalyserNode.fftSize)
+ },
+ mDisplay: {
+ active: false,
+ },
+ paintAnalyzerFrame: function(aTimestamp) {
+ var data = new Uint8Array(gModSound.mAudio.frequencySlices);
+ gModSound.mAudio.analyzer.getByteFrequencyData(data);
+ gModSound.mDisplay.context.clearRect(0, 0, gModSound.mDisplay.canvas.width,
+ gModSound.mDisplay.canvas.height);
+ // Out of experience, only the first half of the slices are actually useful.
+ var wid = gModSound.mDisplay.canvas.width / gModSound.mAudio.frequencySlices;
+ var fill = "#9C9CFF";
+ for (var i = 0; i < gModSound.mAudio.frequencySlices; ++i) {
+ var newFill = (data[i] > 200) ? "#FF0000" :
+ ((data[i] > 100) ? "#FFCF00" : "#9C9CFF");
+ if (fill != newFill) {
+ gModSound.mDisplay.context.fillStyle = newFill; fill = newFill;
+ }
+ gModSound.mDisplay.context.fillRect(i*wid, 0, wid, data[i]);
+ }
+ if (gModSound.mDisplay.active)
+ gModSound.mDisplay.AFRequestID =
+ window.requestAnimationFrame(gModSound.paintAnalyzerFrame);
+ },
+ resize: function() {
+ gModSound.rebuildCanvas();
+ },
+ deactivate: function() {
+ if (gModSound.mDisplay.active) {
+ gModSound.mAudio.stream.stop();
+ gModSound.mDisplay.active = false;
+ }
+ gSounds.scan.pause();
+ },
+}