dashjs/build/es5/src/dash/WebmSegmentBaseLoader.js

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

'use strict';Object.defineProperty(exports,"__esModule",{value:true});var _Events=require('../core/events/Events');var _Events2=_interopRequireDefault(_Events);var _EventBus=require('../core/EventBus');var _EventBus2=_interopRequireDefault(_EventBus);var _EBMLParser=require('../streaming/utils/EBMLParser');var _EBMLParser2=_interopRequireDefault(_EBMLParser);var _Constants=require('../streaming/constants/Constants');var _Constants2=_interopRequireDefault(_Constants);var _FactoryMaker=require('../core/FactoryMaker');var _FactoryMaker2=_interopRequireDefault(_FactoryMaker);var _Debug=require('../core/Debug');var _Debug2=_interopRequireDefault(_Debug);var _RequestModifier=require('../streaming/utils/RequestModifier');var _RequestModifier2=_interopRequireDefault(_RequestModifier);var _Segment=require('./vo/Segment');var _Segment2=_interopRequireDefault(_Segment);var _HTTPRequest=require('../streaming/vo/metrics/HTTPRequest');var _FragmentRequest=require('../streaming/vo/FragmentRequest');var _FragmentRequest2=_interopRequireDefault(_FragmentRequest);var _HTTPLoader=require('../streaming/net/HTTPLoader');var _HTTPLoader2=_interopRequireDefault(_HTTPLoader);var _DashJSError=require('../streaming/vo/DashJSError');var _DashJSError2=_interopRequireDefault(_DashJSError);var _Errors=require('../core/errors/Errors');var _Errors2=_interopRequireDefault(_Errors);function _interopRequireDefault(obj){return obj&&obj.__esModule?obj:{default:obj};}function WebmSegmentBaseLoader(){var context=this.context;var eventBus=(0,_EventBus2.default)(context).getInstance();var instance=void 0,logger=void 0,WebM=void 0,errHandler=void 0,requestModifier=void 0,dashMetrics=void 0,mediaPlayerModel=void 0,httpLoader=void 0,baseURLController=void 0;function setup(){logger=(0,_Debug2.default)(context).getInstance().getLogger(instance);WebM={EBML:{tag:0x1A45DFA3,required:true},Segment:{tag:0x18538067,required:true,SeekHead:{tag:0x114D9B74,required:true},Info:{tag:0x1549A966,required:true,TimecodeScale:{tag:0x2AD7B1,required:true,parse:'getMatroskaUint'},Duration:{tag:0x4489,required:true,parse:'getMatroskaFloat'}},Tracks:{tag:0x1654AE6B,required:true},Cues:{tag:0x1C53BB6B,required:true,CuePoint:{tag:0xBB,required:true,CueTime:{tag:0xB3,required:true,parse:'getMatroskaUint'},CueTrackPositions:{tag:0xB7,required:true,CueTrack:{tag:0xF7,required:true,parse:'getMatroskaUint'},CueClusterPosition:{tag:0xF1,required:true,parse:'getMatroskaUint'}}}}},Void:{tag:0xEC,required:true}};}function initialize(){requestModifier=(0,_RequestModifier2.default)(context).getInstance();httpLoader=(0,_HTTPLoader2.default)(context).create({errHandler:errHandler,dashMetrics:dashMetrics,mediaPlayerModel:mediaPlayerModel,requestModifier:requestModifier});}function setConfig(config){if(!config.baseURLController||!config.dashMetrics||!config.mediaPlayerModel||!config.errHandler){throw new Error(_Constants2.default.MISSING_CONFIG_ERROR);}baseURLController=config.baseURLController;dashMetrics=config.dashMetrics;mediaPlayerModel=config.mediaPlayerModel;errHandler=config.errHandler;}function parseCues(ab){var cues=[];var ebmlParser=(0,_EBMLParser2.default)(context).create({data:ab});var cue=void 0,cueTrack=void 0;ebmlParser.consumeTagAndSize(WebM.Segment.Cues);while(ebmlParser.moreData()&&ebmlParser.consumeTagAndSize(WebM.Segment.Cues.CuePoint,true)){cue={};cue.CueTime=ebmlParser.parseTag(WebM.Segment.Cues.CuePoint.CueTime);cue.CueTracks=[];while(ebmlParser.moreData()&&ebmlParser.consumeTag(WebM.Segment.Cues.CuePoint.CueTrackPositions,true)){var cueTrackPositionSize=ebmlParser.getMatroskaCodedNum();var startPos=ebmlParser.getPos();cueTrack={};cueTrack.Track=ebmlParser.parseTag(WebM.Segment.Cues.CuePoint.CueTrackPositions.CueTrack);if(cueTrack.Track===0){throw new Error('Cue track cannot be 0');}cueTrack.ClusterPosition=ebmlParser.parseTag(WebM.Segment.Cues.CuePoint.CueTrackPositions.CueClusterPosition);cue.CueTracks.push(cueTrack);// we're not interested any other elements - skip remaining bytes
ebmlParser.setPos(startPos+cueTrackPositionSize);}if(cue.CueTracks.length===0){throw new Error('Mandatory cuetrack not found');}cues.push(cue);}if(cues.length===0){throw new Error('mandatory cuepoint not found');}return cues;}function parseSegments(data,segmentStart,segmentEnd,segmentDuration){var duration=void 0,parsed=void 0,segments=void 0,segment=void 0,i=void 0,len=void 0,start=void 0,end=void 0;parsed=parseCues(data);segments=[];// we are assuming one cue track per cue point
// both duration and media range require the i + 1 segment
// the final segment has to use global segment parameters
for(i=0,len=parsed.length;i<len;i+=1){segment=new _Segment2.default();duration=0;if(i<parsed.length-1){duration=parsed[i+1].CueTime-parsed[i].CueTime;}else{duration=segmentDuration-parsed[i].CueTime;}// note that we don't explicitly set segment.media as this will be
// computed when all BaseURLs are resolved later
segment.duration=duration;segment.startTime=parsed[i].CueTime;segment.timescale=1000;// hardcoded for ms
start=parsed[i].CueTracks[0].ClusterPosition+segmentStart;if(i<parsed.length-1){end=parsed[i+1].CueTracks[0].ClusterPosition+segmentStart-1;}else{end=segmentEnd-1;}segment.mediaRange=start+'-'+end;segments.push(segment);}logger.debug('Parsed cues: '+segments.length+' cues.');return segments;}function parseEbmlHeader(data,media,theRange,callback){if(!data||data.byteLength===0){callback(null);return;}var ebmlParser=(0,_EBMLParser2.default)(context).create({data:data});var duration=void 0,segments=void 0,segmentEnd=void 0,segmentStart=void 0;var parts=theRange?theRange.split('-'):null;var request=null;var info={url:media,range:{start:parts?parseFloat(parts[0]):null,end:parts?parseFloat(parts[1]):null},request:request};logger.debug('Parse EBML header: '+info.url);// skip over the header itself
ebmlParser.skipOverElement(WebM.EBML);ebmlParser.consumeTag(WebM.Segment);// segments start here
segmentEnd=ebmlParser.getMatroskaCodedNum();segmentEnd+=ebmlParser.getPos();segmentStart=ebmlParser.getPos();// skip over any top level elements to get to the segment info
while(ebmlParser.moreData()&&!ebmlParser.consumeTagAndSize(WebM.Segment.Info,true)){if(!(ebmlParser.skipOverElement(WebM.Segment.SeekHead,true)||ebmlParser.skipOverElement(WebM.Segment.Tracks,true)||ebmlParser.skipOverElement(WebM.Segment.Cues,true)||ebmlParser.skipOverElement(WebM.Void,true))){throw new Error('no valid top level element found');}}// we only need one thing in segment info, duration
while(duration===undefined){var infoTag=ebmlParser.getMatroskaCodedNum(true);var infoElementSize=ebmlParser.getMatroskaCodedNum();switch(infoTag){case WebM.Segment.Info.Duration.tag:duration=ebmlParser[WebM.Segment.Info.Duration.parse](infoElementSize);break;default:ebmlParser.setPos(ebmlParser.getPos()+infoElementSize);break;}}// once we have what we need from segment info, we jump right to the
// cues
request=getFragmentRequest(info);var onload=function onload(response){segments=parseSegments(response,segmentStart,segmentEnd,duration);callback(segments);};var onloadend=function onloadend(){logger.error('Download Error: Cues '+info.url);callback(null);};httpLoader.load({request:request,success:onload,error:onloadend});logger.debug('Perform cues load: '+info.url+' bytes='+info.range.start+'-'+info.range.end);}function checkConfig(){if(!baseURLController||!baseURLController.hasOwnProperty('resolve')){throw new Error('setConfig function has to be called previously');}}function loadInitialization(representation,loadingInfo){checkConfig();var request=null;var baseUrl=representation?baseURLController.resolve(representation.path):null;var media=baseUrl?baseUrl.url:undefined;var initRange=representation?representation.range.split('-'):null;var info=loadingInfo||{range:{start:initRange?parseFloat(initRange[0]):null,end:initRange?parseFloat(initRange[1]):null},request:request,url:media,init:true};logger.info('Start loading initialization.');request=getFragmentRequest(info);var onload=function onload(){// note that we don't explicitly set rep.initialization as this
// will be computed when all BaseURLs are resolved later
eventBus.trigger(_Events2.default.INITIALIZATION_LOADED,{representation:representation});};var onloadend=function onloadend(){eventBus.trigger(_Events2.default.INITIALIZATION_LOADED,{representation:representation});};httpLoader.load({request:request,success:onload,error:onloadend});logger.debug('Perform init load: '+info.url);}function loadSegments(representation,type,theRange,callback){checkConfig();var request=null;var baseUrl=representation?baseURLController.resolve(representation.path):null;var media=baseUrl?baseUrl.url:undefined;var bytesToLoad=8192;var info={bytesLoaded:0,bytesToLoad:bytesToLoad,range:{start:0,end:bytesToLoad},request:request,url:media,init:false};callback=!callback?onLoaded:callback;request=getFragmentRequest(info);// first load the header, but preserve the manifest range so we can
// load the cues after parsing the header
// NOTE: we expect segment info to appear in the first 8192 bytes
logger.debug('Parsing ebml header');var onload=function onload(response){parseEbmlHeader(response,media,theRange,function(segments){callback(segments,representation,type);});};var onloadend=function onloadend(){callback(null,representation,type);};httpLoader.load({request:request,success:onload,error:onloadend});}function onLoaded(segments,representation,type){if(segments){eventBus.trigger(_Events2.default.SEGMENTS_LOADED,{segments:segments,representation:representation,mediaType:type});}else{eventBus.trigger(_Events2.default.SEGMENTS_LOADED,{segments:null,representation:representation,mediaType:type,error:new _DashJSError2.default(_Errors2.default.SEGMENT_BASE_LOADER_ERROR_CODE,_Errors2.default.SEGMENT_BASE_LOADER_ERROR_MESSAGE)});}}function getFragmentRequest(info){var request=new _FragmentRequest2.default();request.type=info.init?_HTTPRequest.HTTPRequest.INIT_SEGMENT_TYPE:_HTTPRequest.HTTPRequest.MEDIA_SEGMENT_TYPE;request.url=info.url;request.range=info.range.start+'-'+info.range.end;return request;}function reset(){errHandler=null;requestModifier=null;}instance={setConfig:setConfig,initialize:initialize,loadInitialization:loadInitialization,loadSegments:loadSegments,reset:reset};setup();return instance;}WebmSegmentBaseLoader.__dashjs_factory_name='WebmSegmentBaseLoader';exports.default=_FactoryMaker2.default.getSingletonFactory(WebmSegmentBaseLoader);
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