ebml-json

organizes the ebml tags in a json structure


For easier use the Array of Ebml tags, which represents an xml like structure, is parsed to a json tree structure

Example

``js
['start',{tagStr:'1a45dfa3',type:'m',dataSize:35,tag:172351395,name:'EBML',start:0,end:40}]
['tag',{tagStr:'4286',type:'u',dataSize:1,tag:646,name:'EBMLVersion',start:5,end:9,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:1}]
['tag',{tagStr:'42f7',type:'u',dataSize:1,tag:759,name:'EBMLReadVersion',start:9,end:13,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:1}]
['tag',{tagStr:'42f2',type:'u',dataSize:1,tag:754,name:'EBMLMaxIDLength',start:13,end:17,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:4}]
['tag',{tagStr:'42f3',type:'u',dataSize:1,tag:755,name:'EBMLMaxSizeLength',start:17,end:21,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:8}]
['tag',{tagStr:'4282',type:'s',dataSize:8,tag:642,name:'DocType',start:21,end:32,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:'matroska'}]
['tag',{tagStr:'4287',type:'u',dataSize:1,tag:647,name:'DocTypeVersion',start:32,end:36,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:1}]
['tag',{tagStr:'4285',type:'u',dataSize:1,tag:645,name:'DocTypeReadVersion',start:36,end:40,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:1}]
['end',{tag:172351395,tagStr:'1a45dfa3',type:'m',name:'EBML',start:0,end:40,dataSize:35}]
`
into
`js
{
_name:'EBML',
_raw:{tagStr:'1a45dfa3',type:'m',dataSize:35,tag:172351395,name:'EBML',start:0,end:40},
EBMLVersion:{tagStr:'4286',type:'u',dataSize:1,tag:646,name:'EBMLVersion',start:5,end:9,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:1},
EBMLReadVersion:{tagStr:'42f7',type:'u',dataSize:1,tag:759,name:'EBMLReadVersion',start:9,end:13,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:1},
EBMLMaxIDLength:{tagStr:'42f2',type:'u',dataSize:1,tag:754,name:'EBMLMaxIDLength',start:13,end:17,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:4},
EBMLMaxSizeLength:{tagStr:'42f3',type:'u',dataSize:1,tag:755,name:'EBMLMaxSizeLength',start:17,end:21,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:8},
DocType:{tagStr:'4282',type:'s',dataSize:8,tag:642,name:'DocType',start:21,end:32,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:'matroska'},
DocTypeVersion:{tagStr:'4287',type:'u',dataSize:1,tag:647,name:'DocTypeVersion',start:32,end:36,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:1},
DocTypeReadVersion:{tagStr:'4285',type:'u',dataSize:1,tag:645,name:'DocTypeReadVersion',start:36,end:40,data:,discardable:false,keyframe:false,payload:null,track:undefined,value:1},
_rawEnd:{tag:172351395,tagStr:'1a45dfa3',type:'m',name:'EBML',start:0,end:40,dataSize:35}
}
`
with the useValues option set to true
`js
{
_name:'EBML',
_raw:{tagStr:'1a45dfa3',type:'m',dataSize:35,tag:172351395,name:'EBML',start:0,end:40},
EBMLVersion:1,
EBMLReadVersion:1,
EBMLMaxIDLength:4,
EBMLMaxSizeLength:8,
DocType:'matroska',
DocTypeVersion:1,
DocTypeReadVersion:1,
_rawEnd:{tag:172351395,tagStr:'1a45dfa3',type:'m',name:'EBML',start:0,end:40,dataSize:35}
}
`


#Install
This package is intended to be used with the ebml package!

npm\
npm install --save ebml-json


#Usage
* as a transform stream
`js
let Ebml=require("ebml");
let EbmlJson=require("ebml-json");

myStream.pipe(new Ebml.Decoder()).pipe(new EbmlJson()).on("data",function(root)
{
//do stuff with roots here
});
`
* as a parser

`js
let Ebml=require("ebml");
let EbmlJson=require("ebml-json");

let roots=EbmlJson.parse(myTagArray);
//do stuff with roots here
// or
let ebmlStructure=EbmlJson.wrapRoot(roots);
`

Reverse

The json structure can also be reverted into a tag array.

_!! It is not possible if you used the "useValues" option !!_

`js
let EbmlJson=require("ebml-json");
let tags=EbmlJson.taggify(ebmlStructure); // can also consume wrapped roots
`



#Api
###new ebml-json([options])
params
* [options] {Object}
* [options.useValues=false] {Boolean} use value instead of tag contents
* returns stream.Transform
###ebml-json.parse(tags,[options])
params
* [tags] {Array} array of decoded tags
* [options] {Object}
* [options.useValues=false] {Boolean} use value instead of tag contents
* returns {Array\} array of parsed roots
###ebml-json.wrapRoot(roots)
params
* roots {Array\} array of parsed roots
* returns {Object} object containing roots (keys correspond to _name)
###ebml-json.taggify(EbmlStructure)
params
* EbmlStructure {Array\} array of parsed roots
* returns` {Array} array of ebml tags