does not work

package.json

@@ -2,7 +2,6 @@
   "name": "tinode-webapp",
   "description": "Tinode messenger for the web",
   "version": "0.20.2",
-
   "repository": {
     "type": "git",
     "url": "https://github.com/tinode/example-react-js.git"
@@ -71,7 +70,8 @@
     "react": "^17.0.2",
     "react-dom": "^17.0.2",
     "react-intl": "^5.20.2",
-    "tinode-sdk": "^0.20.2"
+    "tinode-sdk": "^0.20.2",
+    "ts-ebml": "^2.0.2"
   },
   "devDependencies": {
     "@babel/core": "^7.14.5",

src/widgets/audio-recorder.jsx

@@ -5,6 +5,7 @@ import React from 'react';
 import AudioPlayer from './audio-player.jsx';
 // Workaround for https://bugs.chromium.org/p/chromium/issues/detail?id=642012
 // import fixWebmDuration from 'fix-webm-duration';
+import * as ebml from 'ts-ebml';
 
 import { intArrayToBase64 } from '../lib/blob-helpers.js'
 import { secondsToTime } from '../lib/strformat';
@@ -269,12 +270,38 @@ export default class AudioRecorder extends React.PureComponent {
   // Obtain data in a form sutable for sending or playing back.
   // If duration is valid, apply fix for Chrome's WebM duration bug.
   getRecording(mimeType, duration) {
-    let blob = new Blob(this.audioChunks, {type: mimeType || AUDIO_MIME_TYPE});
+    mimeType = mimeType || AUDIO_MIME_TYPE;
+    let blob = new Blob(this.audioChunks, {type: mimeType});
+    return this.tempFixMetadata(blob, mimeType)
+      .then(fixedBlob => { blob = fixedBlob; return fixedBlob.arrayBuffer(); })
+      .then(arrayBuff => this.audioContext.decodeAudioData(arrayBuff))
+      .then(decoded => this.createPreview(decoded))
+      .then(preview => ({url: window.URL.createObjectURL(blob), preview: intArrayToBase64(preview)}));
+    /*
     return (duration > 0 ? ysFixWebmDuration(blob, duration, {logger: false}) : Promise.resolve(blob))
       .then(fixedBlob => { blob = fixedBlob; return fixedBlob.arrayBuffer(); })
       .then(arrayBuff => this.audioContext.decodeAudioData(arrayBuff))
       .then(decoded => this.createPreview(decoded))
       .then(preview => ({url: window.URL.createObjectURL(blob), preview: intArrayToBase64(preview)}));
+      */
+  }
+
+  tempFixMetadata(blob, mimeType) {
+    const decoder = new ebml.Decoder();
+    const reader = new ebml.Reader();
+    reader.logging = true;
+    reader.logGroup = "Raw WebM file";
+    reader.drop_default_duration = false;
+    let webmBuf;
+    blob.arrayBuffer()
+      .then(buf => { webmBuf = buf; return decoder.decode(buf); })
+      .then(elms => {
+        elms.forEach(elm => reader.read(elm))
+        reader.stop();
+        const fixedMetadataBuf = ebml.tools.makeMetadataSeekable(reader.metadatas, reader.duration, reader.cues);
+        const body = webmBuf.slice(reader.metadataSize);
+        return new Blob([fixedMetadataBuf, body], {type: mimeType});
+      });
   }
 
   // Preview must be calculated at the source: Chrome does not allow background AudioContext.