@l5i/dashjs/build/es5/src/dash/utils/TimelineSegmentsGetter.js

A reference client implementation for the playback of MPEG DASH via Javascript and compliant browsers.

/**
 * The copyright in this software is being made available under the BSD License,
 * included below. This software may be subject to other third party and contributor
 * rights, including patent rights, and no such rights are granted under this license.
 *
 * Copyright (c) 2013, Dash Industry Forum.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *  * Redistributions of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation and/or
 *  other materials provided with the distribution.
 *  * Neither the name of Dash Industry Forum nor the names of its
 *  contributors may be used to endorse or promote products derived from this software
 *  without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND ANY
 *  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 *  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 *  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 */'use strict';Object.defineProperty(exports,'__esModule',{value:true});function _interopRequireDefault(obj){return obj && obj.__esModule?obj:{'default':obj};}var _coreFactoryMaker=require('../../core/FactoryMaker');var _coreFactoryMaker2=_interopRequireDefault(_coreFactoryMaker);var _SegmentsUtils=require('./SegmentsUtils');function TimelineSegmentsGetter(config,isDynamic){config = config || {};var timelineConverter=config.timelineConverter;var instance=undefined;function checkConfig(){if(!timelineConverter || !timelineConverter.hasOwnProperty('calcMediaTimeFromPresentationTime') || !timelineConverter.hasOwnProperty('calcSegmentAvailabilityRange')){throw new Error('Missing config parameter(s)');}}function getSegmentsFromTimeline(representation,requestedTime,index,availabilityUpperLimit){checkConfig();if(!representation){throw new Error('no representation');}if(requestedTime === undefined){requestedTime = null;}var base=representation.adaptation.period.mpd.manifest.Period_asArray[representation.adaptation.period.index].AdaptationSet_asArray[representation.adaptation.index].Representation_asArray[representation.index].SegmentTemplate || representation.adaptation.period.mpd.manifest.Period_asArray[representation.adaptation.period.index].AdaptationSet_asArray[representation.adaptation.index].Representation_asArray[representation.index].SegmentList;var timeline=base.SegmentTimeline;var list=base.SegmentURL_asArray;var isAvailableSegmentNumberCalculated=representation.availableSegmentsNumber > 0;var maxSegmentsAhead=undefined;if(availabilityUpperLimit){maxSegmentsAhead = availabilityUpperLimit;}else {maxSegmentsAhead = index > -1 || requestedTime !== null?10:Infinity;}var time=0;var scaledTime=0;var availabilityIdx=-1;var segments=[];var requiredMediaTime=null;var fragments=undefined,frag=undefined,i=undefined,len=undefined,j=undefined,repeat=undefined,repeatEndTime=undefined,nextFrag=undefined,hasEnoughSegments=undefined,startIdx=undefined,fTimescale=undefined;var createSegment=function createSegment(s,i){var media=base.media;var mediaRange=s.mediaRange;if(list){media = list[i].media || '';mediaRange = list[i].mediaRange;}return (0,_SegmentsUtils.getTimeBasedSegment)(timelineConverter,isDynamic,representation,time,s.d,fTimescale,media,mediaRange,availabilityIdx,s.tManifest);};fTimescale = representation.timescale;fragments = timeline.S_asArray;startIdx = index;if(requestedTime !== null){requiredMediaTime = timelineConverter.calcMediaTimeFromPresentationTime(requestedTime,representation);}for(i = 0,len = fragments.length;i < len;i++) {frag = fragments[i];repeat = 0;if(frag.hasOwnProperty('r')){repeat = frag.r;} // For a repeated S element, t belongs only to the first segment
if(frag.hasOwnProperty('t')){time = frag.t;scaledTime = time / fTimescale;} // This is a special case: "A negative value of the @r attribute of the S element indicates that the duration indicated in @d attribute repeats until the start of the next S element, the end of the Period or until the
// next MPD update."
if(repeat < 0){nextFrag = fragments[i + 1];if(nextFrag && nextFrag.hasOwnProperty('t')){repeatEndTime = nextFrag.t / fTimescale;}else {var availabilityEnd=representation.segmentAvailabilityRange?representation.segmentAvailabilityRange.end:timelineConverter.calcSegmentAvailabilityRange(representation,isDynamic).end;repeatEndTime = timelineConverter.calcMediaTimeFromPresentationTime(availabilityEnd,representation);representation.segmentDuration = frag.d / fTimescale;}repeat = Math.ceil((repeatEndTime - scaledTime) / (frag.d / fTimescale)) - 1;} // if we have enough segments in the list, but we have not calculated the total number of the segments yet we
// should continue the loop and calc the number. Once it is calculated, we can break the loop.
if(hasEnoughSegments){if(isAvailableSegmentNumberCalculated)break;availabilityIdx += repeat + 1;continue;}for(j = 0;j <= repeat;j++) {availabilityIdx++;if(segments.length > maxSegmentsAhead){hasEnoughSegments = true;if(isAvailableSegmentNumberCalculated)break;continue;}if(requiredMediaTime !== null){ // In some cases when requiredMediaTime = actual end time of the last segment
// it is possible that this time a bit exceeds the declared end time of the last segment.
// in this case we still need to include the last segment in the segment list. to do this we
// use a correction factor = 1.5. This number is used because the largest possible deviation is
// is 50% of segment duration.
if(scaledTime >= requiredMediaTime - frag.d / fTimescale * 1.5){segments.push(createSegment(frag,availabilityIdx));}}else if(availabilityIdx >= startIdx){segments.push(createSegment(frag,availabilityIdx));}time += frag.d;scaledTime = time / fTimescale;}}if(!isAvailableSegmentNumberCalculated){representation.availableSegmentsNumber = availabilityIdx + 1;}return segments;}instance = {getSegments:getSegmentsFromTimeline};return instance;}TimelineSegmentsGetter.__dashjs_factory_name = 'TimelineSegmentsGetter';var factory=_coreFactoryMaker2['default'].getClassFactory(TimelineSegmentsGetter);exports['default'] = factory;module.exports = exports['default'];
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