@l5i/dashjs
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A reference client implementation for the playback of MPEG DASH via Javascript and compliant browsers.
39 lines (38 loc) • 3.98 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 _coreFactoryMaker=require('../../core/FactoryMaker');var _coreFactoryMaker2=_interopRequireDefault(_coreFactoryMaker);var _SwitchRequest=require('./SwitchRequest');var _SwitchRequest2=_interopRequireDefault(_SwitchRequest);var SWITCH_REQUEST_HISTORY_DEPTH=8; // must be > SwitchHistoryRule SAMPLE_SIZE to enable rule
function SwitchRequestHistory(){var switchRequests=[]; // running total
var srHistory=[]; // history of each switch
function push(switchRequest){if(switchRequest.newValue === _SwitchRequest2['default'].NO_CHANGE){switchRequest.newValue = switchRequest.oldValue;}if(!switchRequests[switchRequest.oldValue]){switchRequests[switchRequest.oldValue] = {noDrops:0,drops:0,dropSize:0};} // Set switch details
var indexDiff=switchRequest.newValue - switchRequest.oldValue;var drop=indexDiff < 0?1:0;var dropSize=drop?-indexDiff:0;var noDrop=drop?0:1; // Update running totals
switchRequests[switchRequest.oldValue].drops += drop;switchRequests[switchRequest.oldValue].dropSize += dropSize;switchRequests[switchRequest.oldValue].noDrops += noDrop; // Save to history
srHistory.push({idx:switchRequest.oldValue,noDrop:noDrop,drop:drop,dropSize:dropSize}); // Shift earliest switch off srHistory and readjust to keep depth of running totals constant
if(srHistory.length > SWITCH_REQUEST_HISTORY_DEPTH){var srHistoryFirst=srHistory.shift();switchRequests[srHistoryFirst.idx].drops -= srHistoryFirst.drop;switchRequests[srHistoryFirst.idx].dropSize -= srHistoryFirst.dropSize;switchRequests[srHistoryFirst.idx].noDrops -= srHistoryFirst.noDrop;}}function getSwitchRequests(){return switchRequests;}function reset(){switchRequests = [];srHistory = [];}return {push:push,getSwitchRequests:getSwitchRequests,reset:reset};}SwitchRequestHistory.__dashjs_factory_name = 'SwitchRequestHistory';var factory=_coreFactoryMaker2['default'].getClassFactory(SwitchRequestHistory);exports['default'] = factory;module.exports = exports['default'];
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