Fix transmuxer worker error forwarding (#7883)

* Fix transmuxer worker error forwarding (missing instanceNo)
Found testing #4958 with worker: "Containerless ec-3 is not supported"

* Add missing overserver teardown

src/demux/transmuxer-worker.ts

@@ -30,8 +30,12 @@ function startWorker() {
     if (data.cmd === 'init') {
       const config = JSON.parse(data.config);
       const observer = new EventEmitter();
-      observer.on(Events.FRAG_DECRYPTED, forwardMessage);
-      observer.on(Events.ERROR, forwardMessage);
+      observer.on(Events.FRAG_DECRYPTED, (event, data) =>
+        forwardMessage(event, data, instanceNo),
+      );
+      observer.on(Events.ERROR, (event, data) =>
+        forwardMessage(event, data, instanceNo),
+      );
       const logger = enableLogs(config.debug, data.id);
       forwardWorkerLogs(logger, instanceNo);
       transmuxers[instanceNo] = new Transmuxer(

src/demux/transmuxer.ts

@@ -363,6 +363,9 @@ export default class Transmuxer {
       this.remuxer.destroy();
       this.remuxer = undefined;
     }
+    if (this.observer) {
+      this.observer.removeAllListeners();
+    }
     this.decryptionPromise = null;
     this.decrypter = this.observer = undefined;
     //@ts-ignore