CC-2301 : showing waveform cue/fade editors inside of a jquery dialog box.

airtime_mvc/public/js/waveformplaylist/playout.js

@@ -0,0 +1,161 @@
+'use strict';
+
+var AudioPlayout = function() {
+
+};
+
+AudioPlayout.prototype.init = function(config) {
+
+    makePublisher(this);
+
+    this.config = config;
+    this.ac = this.config.getAudioContext();
+
+    this.fadeMaker = new Fades();
+    this.fadeMaker.init(this.ac.sampleRate);
+    
+    this.gainNode = undefined;
+    this.destination = this.ac.destination;
+    this.analyser = this.ac.createAnalyser();
+    this.analyser.connect(this.destination);
+};
+
+AudioPlayout.prototype.getBuffer = function() {
+    return this.buffer;
+};
+
+AudioPlayout.prototype.setBuffer = function(buffer) {
+    this.buffer = buffer;
+};
+
+/*
+    param relPos: cursor position in seconds relative to this track.
+        can be negative if the cursor is placed before the start of this track etc.
+*/
+AudioPlayout.prototype.applyFades = function(fades, relPos, now, delay) {
+    var id,
+        fade,
+        fn,
+        options,
+        startTime,
+        duration;
+
+    this.gainNode && this.gainNode.disconnect();
+    this.gainNode = this.ac.createGainNode();
+
+    for (id in fades) {
+
+        fade = fades[id];
+
+        if (relPos <= fade.start) {
+            startTime = now + (fade.start - relPos) + delay;
+            duration = fade.end - fade.start;
+        }
+        else if (relPos > fade.start && relPos < fade.end) {
+            startTime = now - (relPos - fade.start) + delay;
+            duration = fade.end - fade.start;
+        }
+
+        options = {
+            start: startTime,
+            duration: duration
+        };
+
+        if (fades.hasOwnProperty(id)) {
+            fn = this.fadeMaker["create"+fade.type];
+            fn.call(this.fadeMaker, this.gainNode.gain, fade.shape, options);
+        }
+    }
+};
+
+/**
+ * Loads audiobuffer.
+ *
+ * @param {AudioBuffer} audioData Audio data.
+ */
+AudioPlayout.prototype.loadData = function (audioData, cb) {
+    var that = this;
+
+    this.ac.decodeAudioData(
+        audioData,
+        function (buffer) {
+            that.buffer = buffer;
+            cb(buffer);
+        },
+        Error
+    );
+};
+
+AudioPlayout.prototype.isUnScheduled = function() {
+    return this.source && (this.source.playbackState === this.source.UNSCHEDULED_STATE);
+};
+
+AudioPlayout.prototype.isScheduled = function() {
+    return this.source && (this.source.playbackState === this.source.SCHEDULED_STATE);
+};
+
+AudioPlayout.prototype.isPlaying = function() {
+    return this.source && (this.source.playbackState === this.source.PLAYING_STATE);
+};
+
+AudioPlayout.prototype.isFinished = function() {
+    return this.source && (this.source.playbackState === this.source.FINISHED_STATE);
+};
+
+AudioPlayout.prototype.getDuration = function() {
+    return this.buffer.duration;
+};
+
+AudioPlayout.prototype.getPlayOffset = function() {
+    var offset = 0;
+
+    //TODO needs a fix for when the buffer naturally plays out. But also have to mind the entire playlist.
+    if (this.playing) {
+        offset = this.secondsOffset + (this.ac.currentTime - this.playTime);
+    }
+    else {
+        offset = this.secondsOffset;
+    }
+
+    return offset;
+};
+
+AudioPlayout.prototype.setPlayedPercents = function(percent) {
+    this.secondsOffset = this.getDuration() * percent;
+};
+
+AudioPlayout.prototype.getPlayedPercents = function() {
+    return this.getPlayOffset() / this.getDuration();
+};
+
+AudioPlayout.prototype.setSource = function(source) {
+    this.source && this.source.disconnect();
+    this.source = source;
+    this.source.buffer = this.buffer;
+
+    this.source.connect(this.gainNode);
+    this.gainNode.connect(this.analyser);
+};
+
+/*
+    source.start is picky when passing the end time. 
+    If rounding error causes a number to make the source think 
+    it is playing slightly more samples than it has it won't play at all.
+    Unfortunately it doesn't seem to work if you just give it a start time.
+*/
+AudioPlayout.prototype.play = function(when, start, duration) {
+    if (!this.buffer) {
+        console.error("no buffer to play");
+        return;
+    }
+
+    this.setSource(this.ac.createBufferSource());
+  
+    this.source.start(when || 0, start, duration);
+};
+
+AudioPlayout.prototype.stop = function(when) {
+ 
+    this.source && this.source.stop(when || 0);
+};
+