118 |
137 |
138 |
139 |
140 |
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/instacall/js/detect-silence.js:
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1 | window.instacall || (window.instacall = {});
2 | (function () {
3 |
4 | // adapted from https://github.com/muaz-khan/WebRTC-Experiment/tree/master/RecordRTC
5 | function detectSilence (mediaStream, duration, onSilence) {
6 | // creates the audio context
7 | var audioContext = window.AudioContext || window.webkitAudioContext;
8 |
9 | if (!audioContext) {
10 | return;
11 | }
12 |
13 | var context = new audioContext();
14 |
15 | if (!context || !context.createGain || !context.createMediaStreamSource || !context.createScriptProcessor) {
16 | return;
17 | }
18 |
19 | // creates a gain node
20 | var volume = context.createGain();
21 |
22 | // creates an audio node from the microphone incoming stream
23 | var audioInput = context.createMediaStreamSource(mediaStream);
24 |
25 | // connect the stream to the gain node
26 | audioInput.connect(volume);
27 |
28 | // From the spec: This value controls how frequently the audioprocess event is
29 | // dispatched and how many sample-frames need to be processed each call.
30 | // Lower values for buffer size will result in a lower (better) latency.
31 | // Higher values will be necessary to avoid audio breakup and glitches
32 |
33 | // bug: how to minimize wav size?
34 |
35 | // The size of the buffer (in sample-frames) which needs to
36 | // be processed each time onprocessaudio is called.
37 | // Legal values are (256, 512, 1024, 2048, 4096, 8192, 16384).
38 | var legalBufferValues = [256, 512, 1024, 2048, 4096, 8192, 16384];
39 | var bufferSize = 2048;
40 |
41 | if (legalBufferValues.indexOf(bufferSize) == -1) {
42 | throw 'Legal values for buffer-size are ' + JSON.stringify(legalBufferValues, null, '\t');
43 | }
44 |
45 | // The sample rate (in sample-frames per second) at which the
46 | // AudioContext handles audio. It is assumed that all AudioNodes
47 | // in the context run at this rate. In making this assumption,
48 | // sample-rate converters or "varispeed" processors are not supported
49 | // in real-time processing.
50 |
51 | // The sampleRate parameter describes the sample-rate of the
52 | // linear PCM audio data in the buffer in sample-frames per second.
53 | // An implementation must support sample-rates in at least
54 | // the range 22050 to 96000.
55 | var sampleRate = context.sampleRate || 44100;
56 |
57 | if (sampleRate < 22050 || sampleRate > 96000) {
58 | throw 'sample-rate must be under range 22050 and 96000.';
59 | }
60 |
61 | console.log('sample-rate', sampleRate);
62 | console.log('buffer-size', bufferSize);
63 |
64 | var recorder = context.createScriptProcessor(bufferSize, 2, 2);
65 |
66 | var lastHeard = new Date().getTime();
67 |
68 | recorder.onaudioprocess = function(e) {
69 | if (mediaStream.ended) {
70 | recorder.onaudioprocess = function () {};
71 | return;
72 | }
73 | var time = new Date().getTime();
74 | var left = e.inputBuffer.getChannelData(0);
75 | var allzeros = true;
76 | for (var i = 0; i < left.length; i++) {
77 | if (left[i] != 0) {
78 | allzeros = false;
79 | break;
80 | }
81 | }
82 | // assume disabled streams aren't broken
83 | if (!allzeros || !mediaStream.getAudioTracks()[0].enabled) {
84 | lastHeard = time;
85 | }
86 | else if ((time - lastHeard) > duration && !onSilence(mediaStream)) {
87 | recorder.onaudioprocess = function () {};
88 | }
89 | };
90 |
91 | // we connect the recorder
92 | volume.connect(recorder);
93 | recorder.connect(context.destination);
94 | }
95 |
96 | // Export function for global access
97 | instacall.Detector || (instacall.Detector = {});
98 | instacall.Detector.detectSilence = detectSilence;
99 |
100 | }());
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/instacall/js/detect-video-freeze.js:
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1 | window.instacall || (window.instacall = {});
2 |
3 | (function () {
4 |
5 | /*
6 | Call a function whenever this video freezes. Uses two offscreen canvases to compare video frames.
7 | The
