ebml decoder and encoder
npm install ts-ebml``
npm install ts-ebml --save
`console`
$ ts-ebml foo.webm
0 m 0 EBML
5 u 1 EBMLVersion 1
9 u 1 EBMLReadVersion 1
13 u 1 EBMLMaxIDLength 4
17 u 1 EBMLMaxSizeLength 8
21 s 1 DocType webm
28 u 1 DocTypeVersion 2
32 u 1 DocTypeReadVersion 2
36 m 0 Segment
48 m 1 Info
53 u 2 TimecodeScale 1000000
...
`console`
$ ts-ebml -s input.webm | cat > seekable.webm
`ts
import * as ebml from 'ts-ebml';
const fs = require('fs');
const decoder = new ebml.Decoder();
fs.createReadStream('media/test.webm').on('data', (buf)=>{
const ebmlElms = decoder.decode(buf);
console.log(ebmlElms);
});
`
`html`
bundle
`ts
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 VP8 Stream
* create seekable webm from media-recoder
* create playable webm to media-stream-api from media-recorder
see src/test.ts and src/example_seekable.ts
`ts
class Decoder {
constructor();
decode(chunk: ArrayBuffer): EBMLElementDetail[];
}
class Encoder {
constructor();
encode(elms: EBMLElementBuffer[]): ArrayBuffer;
}
type EBMLElementBuffer = MasterElement | ChildElementBuffer;
type EBMLElementDetail = (MasterElement | ChildElementValue) & ElementDetail;
type MasterElement = {
name: string;
type: "m";
isEnd: boolean;
unknownSize?: boolean;
};
type ChildElementBuffer = {
name: string;
type: "u" | "i" | "f" | "s" | "8" | "b" | "d";
data: Buffer;
};
type ChildElementValue = ChildElementBuffer & {
value: number|string|Buffer|Date;
};
type ElementDetail = {
tagStart: number;
tagEnd: number;
sizeStart: number;
sizeEnd: number;
dataStart: number;
dataEnd: number;
};
namespace tools {
export function readVint(buffer: Buffer, start: number): null | ({length: number; value: number; });
export function writeVint(val: number): Buffer;
export function readBlock(buf: ArrayBuffer): EBML.SimpleBlock;
}
`
`sh`
npm install
npm run build # build js code
npm run lint # tslint
npm run doc # typedoc
npm run lint # type check (watch)
npm test # build and run tests
* https://www.matroska.org/downloads/mkvalidator.html
* https://www.matroska.org/downloads/mkclean.html
* https://mkvtoolnix.download/doc/mkvinfo.html
* https://github.com/ietf-wg-cellar/matroska-test-files
* MOZ_LOG_FILE="log.txt" MOZ_LOG="MediaDemuxer:5" /Applications/FirefoxNightly.app/Contents/MacOS/firefox-bin
*
* chrome://media-internals/
* chrome://webrtc-internals/
./out/gn/Chromium.app/Contents/MacOS/Chromium -vmodule="video=0,ffmpeg=1,media*=1" https://webrtc.github.io/samples/src/content/getusermedia/record/
*
*
*
MIT
* https://www.matroska.org/technical/specs/index.html
* https://www.matroska.org/technical/specs/notes.html
* https://www.matroska.org/technical/order/index.html
* MediaRecorder output should have Cues element - https://bugs.chromium.org/p/chromium/issues/detail?id=561606
* Videos created with MediaRecorder API are not seekable / scrubbable - https://bugs.chromium.org/p/chromium/issues/detail?id=569840
* No duration or seeking cue for opus audio produced with mediarecoder - https://bugs.chromium.org/p/chromium/issues/detail?id=599134
* MediaRecorder: consider producing seekable WebM files - https://bugs.chromium.org/p/chromium/issues/detail?id=642012
* Seeking in WebM files with no Cues element is not supported - https://bugzilla.mozilla.org/show_bug.cgi?id=657791
* Recorder video clips result can't replay /seekable on firefox - https://bugzilla.mozilla.org/show_bug.cgi?id=969290
* Optimizing WebM Video for Faster Streaming and Seeking - https://rigor.com/blog/2016/02/optimizing-webm-video-for-faster-streaming-and-seeking
* Creation of Seekable Files - https://github.com/w3c/mediacapture-record/issues/119
* MediaSource api not able to play webm video recorded from MediaRecorder - https://bugs.chromium.org/p/chromium/issues/detail?id=606000
* Video playback freezes using MediaSource API (MSE) - https://bugs.chromium.org/p/chromium/issues/detail?id=678269
* MediaSource API: Appending chunks to a SourceBuffer creates gaps and playback stops - https://bugs.chromium.org/p/chromium/issues/detail?id=688490
* Playback of video segments freezes with errors in media-internals - https://bugs.chromium.org/p/chromium/issues/detail?id=711829
* Regression: Playback of mediaStream recording shows blank video - https://bugs.chromium.org/p/chromium/issues/detail?id=657532
* Webm video recorded with MediaRecorder cannot be played more than once - https://bugzilla.mozilla.org/show_bug.cgi?id=1272371
* https://github.com/antimatter15/js-ebml
* https://bitbucket.org/desmaj/libvpx.js/src/1ea3218282b6eb129061341831d23409dd539054/webm.js
* https://github.com/themasch/node-ebml
* https://github.com/oeuillot/node-matroska
* https://github.com/eadle/webm-byte-stream
* https://github.com/mafintosh/webm-cluster-stream
* https://github.com/Matroska-Org/libebml/
* https://github.com/Matroska-Org/foundation-source
* https://github.com/webmproject/libwebm
* https://chromium.googlesource.com/webm/libvpx/+/master/third_party/libwebm
* https://github.com/mozilla/gecko-dev/tree/master/dom/media/webm
* https://github.com/yellowdoge/libwebm