53 lines
2.0 KiB
JavaScript
53 lines
2.0 KiB
JavaScript
"use strict";
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/**
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* mux.js
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*
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* Copyright (c) Brightcove
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* Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
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*/
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var highPrefix = [33, 16, 5, 32, 164, 27];
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var lowPrefix = [33, 65, 108, 84, 1, 2, 4, 8, 168, 2, 4, 8, 17, 191, 252];
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var zeroFill = function zeroFill(count) {
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var a = [];
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while (count--) {
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a.push(0);
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}
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return a;
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};
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var makeTable = function makeTable(metaTable) {
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return Object.keys(metaTable).reduce(function (obj, key) {
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obj[key] = new Uint8Array(metaTable[key].reduce(function (arr, part) {
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return arr.concat(part);
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}, []));
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return obj;
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}, {});
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};
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var silence;
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module.exports = function () {
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if (!silence) {
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// Frames-of-silence to use for filling in missing AAC frames
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var coneOfSilence = {
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96000: [highPrefix, [227, 64], zeroFill(154), [56]],
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88200: [highPrefix, [231], zeroFill(170), [56]],
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64000: [highPrefix, [248, 192], zeroFill(240), [56]],
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48000: [highPrefix, [255, 192], zeroFill(268), [55, 148, 128], zeroFill(54), [112]],
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44100: [highPrefix, [255, 192], zeroFill(268), [55, 163, 128], zeroFill(84), [112]],
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32000: [highPrefix, [255, 192], zeroFill(268), [55, 234], zeroFill(226), [112]],
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24000: [highPrefix, [255, 192], zeroFill(268), [55, 255, 128], zeroFill(268), [111, 112], zeroFill(126), [224]],
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16000: [highPrefix, [255, 192], zeroFill(268), [55, 255, 128], zeroFill(268), [111, 255], zeroFill(269), [223, 108], zeroFill(195), [1, 192]],
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12000: [lowPrefix, zeroFill(268), [3, 127, 248], zeroFill(268), [6, 255, 240], zeroFill(268), [13, 255, 224], zeroFill(268), [27, 253, 128], zeroFill(259), [56]],
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11025: [lowPrefix, zeroFill(268), [3, 127, 248], zeroFill(268), [6, 255, 240], zeroFill(268), [13, 255, 224], zeroFill(268), [27, 255, 192], zeroFill(268), [55, 175, 128], zeroFill(108), [112]],
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8000: [lowPrefix, zeroFill(268), [3, 121, 16], zeroFill(47), [7]]
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};
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silence = makeTable(coneOfSilence);
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}
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return silence;
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}; |