Package Exports
- ts-ebml
This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (ts-ebml) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.
Readme
ts-ebml
ebml encoder and decoder written in TypeScript.
Fork of node-ebml
It is a fork of https://github.com/themasch/node-ebml
install
npm install ts-ebml --saveexample
node
import * as ebml from 'ts-ebml';
const fs = require('fs');
const decoder = new ebml.Decoder();
fs.readFile('media/test.webm', (err, buf)=>{
if (err){ throw err; }
const ebmlElms = decoder.decode(buf);
console.log(ebmlElms);
});browser
import * as ebml from 'ts-ebml';
const decoder = new ebml.Decoder();
fetch('media/test.webm')
.then((res)=> res.arrayBuffer() )
.then((buf)=>{
const ebmlElms = decoder.decode(buf);
console.log(ebmlElms);
});get WebP frame from MediaRecorder WebM Stream
import {Decoder, Encoder, tools} from "ts-ebml";
import * as EBML from "ts-ebml";
async function main() {
const decoder = new Decoder();
const stream = await navigator.mediaDevices.getUserMedia({video: true, audio: true});
const rec = new MediaRecorder(stream, { mimeType: 'video/webm; codecs="vp8, opus"' });
let tasks = Promise.resolve(void 0);
rec.ondataavailable = (ev: BlobEvent)=>{
const chunk = ev.data;
const task = async ()=>{
const buf = await readAsArrayBuffer(chunk);
const chunks = decoder.decode(buf);
const WebPs = tools.WebPFrameFilter(chunks);
WebPs.forEach((WebP)=>{
const img = new Image();
img.src = URL.createObjectURL(WebP);
document.body.appendChild(img);
});
};
tasks = tasks.then(()=> task() );
};
rec.start(100);
await new Promise((resolve)=> setTimeout(resolve, 30 * 1000) ); // 30 sec
rec.stop();
rec.ondataavailable = <any>undefined;
rec.stream.getTracks().map((track) => { track.stop(); });
await tasks;
}get seekable webm from media-recoder
import EBMLReader from 'ts-ebml/lib/EBMLReader';
import {Decoder, Encoder, tools} from "ts-ebml";
import * as EBML from "ts-ebml";
const file = "media-recoder.webm";
async function main(){
const res = await fetch(file);
const webm_buf = await res.arrayBuffer();
const elms = new Decoder().decode(webm_buf);
let metadataElms: EBML.EBMLElementDetail[] = [];
let segmentOffset = 0;
let metadataSize = 0;
let last_duration = 0;
const cluster_ptrs: number[] = [];
const reader = new EBMLReader();
reader.logging = true;
reader.addListener("metadata", ({data, metadataSize: size})=>{
metadataElms = data;
metadataSize = size;
});
reader.addListener("cluster_ptr", (ptr)=>{
cluster_ptrs.push(ptr);
});
reader.addListener("cue_info", ({CueTrack, CueClusterPosition, CueTime})=>{
cue_points.push({CueTrack, CueClusterPosition, CueTime});
})
reader.addListener("duration", ({timecodeScale, duration})=>{
last_duration = duration;
});
elms.forEach((elm)=>{ reader.read(elm); });
reader.stop();
const refinedMetadataBuf = tools.putRefinedMetaData(metadataElms, {duration: last_duration, clusterPtrs: cluster_ptrs, cueInfos: cue_points});
const body = webm_buf.slice(metadataSize);
const raw_webM = new Blob([webm_buf], {type: "video/webm"});
const refinedWebM = new Blob([refinedMetadataBuf, body], {type: "video/webm"});
const raw_video = await fetchVideo(URL.createObjectURL(raw_webM));
const refined_video = await fetchVideo(URL.createObjectURL(refinedWebM));
document.body.appendChild(raw_video);
document.body.appendChild(refined_video);
}
function fetchVideo(src: string): Promise<HTMLVideoElement>{
return new Promise((resolve, reject)=>{
const video = document.createElement("video");
video.src = src;
video.controls = true;
video.onloadeddata = ()=>{
video.onloadeddata = <any>null;
resolve(video);
};
video.onerror = (err)=>{
video.onerror = <any>null;
reject(err);
};
});
}develop
npm run setup # install cli tools
npm run init # install libraries
npm run build # build js code
npm run lint # tslint
npm run doc # typedoc
npm run check # type check
npm run test # build test
npm run example # build exampletools
- https://www.matroska.org/downloads/mkvalidator.html
- https://mkvtoolnix.download/doc/mkvinfo.html
- https://github.com/Matroska-Org/matroska-test-files
license
MIT
related works
- https://github.com/antimatter15/js-ebml
- https://github.com/themasch/node-ebml
- https://github.com/oeuillot/node-matroska
- https://github.com/Matroska-Org/libebml/
- https://chromium.googlesource.com/webm/libvpx/+/master/third_party/libwebm
- https://github.com/mozilla/gecko-dev/tree/master/dom/media/webm
- https://bitbucket.org/desmaj/libvpx.js/src/1ea3218282b6eb129061341831d23409dd539054/webm.js