@l5i/dashjs
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A reference client implementation for the playback of MPEG DASH via Javascript and compliant browsers.
33 lines (32 loc) • 6.98 kB
JavaScript
/**
* 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 _SwitchRequest=require('../SwitchRequest');var _SwitchRequest2=_interopRequireDefault(_SwitchRequest);var _coreFactoryMaker=require('../../../core/FactoryMaker');var _coreFactoryMaker2=_interopRequireDefault(_coreFactoryMaker);var _coreDebug=require('../../../core/Debug');var _coreDebug2=_interopRequireDefault(_coreDebug);function AbandonRequestsRule(config){config = config || {};var ABANDON_MULTIPLIER=1.8;var GRACE_TIME_THRESHOLD=500;var MIN_LENGTH_TO_AVERAGE=5;var context=this.context;var mediaPlayerModel=config.mediaPlayerModel;var metricsModel=config.metricsModel;var dashMetrics=config.dashMetrics;var instance=undefined,logger=undefined,fragmentDict=undefined,abandonDict=undefined,throughputArray=undefined;function setup(){logger = (0,_coreDebug2['default'])(context).getInstance().getLogger(instance);reset();}function setFragmentRequestDict(type,id){fragmentDict[type] = fragmentDict[type] || {};fragmentDict[type][id] = fragmentDict[type][id] || {};}function storeLastRequestThroughputByType(type,throughput){throughputArray[type] = throughputArray[type] || [];throughputArray[type].push(throughput);}function shouldAbandon(rulesContext){var switchRequest=(0,_SwitchRequest2['default'])(context).create(_SwitchRequest2['default'].NO_CHANGE,{name:AbandonRequestsRule.__dashjs_factory_name});if(!rulesContext || !rulesContext.hasOwnProperty('getMediaInfo') || !rulesContext.hasOwnProperty('getMediaType') || !rulesContext.hasOwnProperty('getCurrentRequest') || !rulesContext.hasOwnProperty('getRepresentationInfo') || !rulesContext.hasOwnProperty('getAbrController')){return switchRequest;}var mediaInfo=rulesContext.getMediaInfo();var mediaType=rulesContext.getMediaType();var req=rulesContext.getCurrentRequest();if(!isNaN(req.index)){setFragmentRequestDict(mediaType,req.index);var stableBufferTime=mediaPlayerModel.getStableBufferTime();var bufferLevel=dashMetrics.getCurrentBufferLevel(metricsModel.getReadOnlyMetricsFor(mediaType));if(bufferLevel > stableBufferTime){return switchRequest;}var fragmentInfo=fragmentDict[mediaType][req.index];if(fragmentInfo === null || req.firstByteDate === null || abandonDict.hasOwnProperty(fragmentInfo.id)){return switchRequest;} //setup some init info based on first progress event
if(fragmentInfo.firstByteTime === undefined){throughputArray[mediaType] = [];fragmentInfo.firstByteTime = req.firstByteDate.getTime();fragmentInfo.segmentDuration = req.duration;fragmentInfo.bytesTotal = req.bytesTotal;fragmentInfo.id = req.index;}fragmentInfo.bytesLoaded = req.bytesLoaded;fragmentInfo.elapsedTime = new Date().getTime() - fragmentInfo.firstByteTime;if(fragmentInfo.bytesLoaded > 0 && fragmentInfo.elapsedTime > 0){storeLastRequestThroughputByType(mediaType,Math.round(fragmentInfo.bytesLoaded * 8 / fragmentInfo.elapsedTime));}if(throughputArray[mediaType].length >= MIN_LENGTH_TO_AVERAGE && fragmentInfo.elapsedTime > GRACE_TIME_THRESHOLD && fragmentInfo.bytesLoaded < fragmentInfo.bytesTotal){var totalSampledValue=throughputArray[mediaType].reduce(function(a,b){return a + b;},0);fragmentInfo.measuredBandwidthInKbps = Math.round(totalSampledValue / throughputArray[mediaType].length);fragmentInfo.estimatedTimeOfDownload = +(fragmentInfo.bytesTotal * 8 / fragmentInfo.measuredBandwidthInKbps / 1000).toFixed(2);if(fragmentInfo.estimatedTimeOfDownload < fragmentInfo.segmentDuration * ABANDON_MULTIPLIER || rulesContext.getRepresentationInfo().quality === 0){return switchRequest;}else if(!abandonDict.hasOwnProperty(fragmentInfo.id)){var abrController=rulesContext.getAbrController();var bytesRemaining=fragmentInfo.bytesTotal - fragmentInfo.bytesLoaded;var bitrateList=abrController.getBitrateList(mediaInfo);var newQuality=abrController.getQualityForBitrate(mediaInfo,fragmentInfo.measuredBandwidthInKbps * mediaPlayerModel.getBandwidthSafetyFactor());var estimateOtherBytesTotal=fragmentInfo.bytesTotal * bitrateList[newQuality].bitrate / bitrateList[abrController.getQualityFor(mediaType,mediaInfo.streamInfo)].bitrate;if(bytesRemaining > estimateOtherBytesTotal){switchRequest.quality = newQuality;switchRequest.reason.throughput = fragmentInfo.measuredBandwidthInKbps;switchRequest.reason.fragmentID = fragmentInfo.id;abandonDict[fragmentInfo.id] = fragmentInfo;logger.debug('( ',mediaType,'frag id',fragmentInfo.id,') is asking to abandon and switch to quality to ',newQuality,' measured bandwidth was',fragmentInfo.measuredBandwidthInKbps);delete fragmentDict[mediaType][fragmentInfo.id];}}}else if(fragmentInfo.bytesLoaded === fragmentInfo.bytesTotal){delete fragmentDict[mediaType][fragmentInfo.id];}}return switchRequest;}function reset(){fragmentDict = {};abandonDict = {};throughputArray = [];}instance = {shouldAbandon:shouldAbandon,reset:reset};setup();return instance;}AbandonRequestsRule.__dashjs_factory_name = 'AbandonRequestsRule';exports['default'] = _coreFactoryMaker2['default'].getClassFactory(AbandonRequestsRule);module.exports = exports['default'];
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