Process is not defined

Hi there,
I need some help so, I clone this repo and run but I got error as below
```
createFFmpeg.js:167 Uncaught (in promise) Error: Oops, something went wrong in FS operation.
at Object.FS (createFFmpeg.js:167:1)
at doTranscode (App.js:15:1)
FS @ createFFmpeg.js:167
doTranscode @ App.js:15
await in doTranscode (async)
callCallback @ react-dom.development.js:188
invokeGuardedCallbackDev @ react-dom.development.js:237
invokeGuardedCallback @ react-dom.development.js:292
invokeGuardedCallbackAndCatchFirstError @ react-dom.development.js:306
executeDispatch @ react-dom.development.js:389
executeDispatchesInOrder @ react-dom.development.js:414
executeDispatchesAndRelease @ react-dom.development.js:3278
executeDispatchesAndReleaseTopLevel @ react-dom.development.js:3287
forEachAccumulated @ react-dom.development.js:3259
runEventsInBatch @ react-dom.development.js:3304
runExtractedPluginEventsInBatch @ react-dom.development.js:3514
handleTopLevel @ react-dom.development.js:3558
batchedEventUpdates$1 @ react-dom.development.js:21871
batchedEventUpdates @ react-dom.development.js:795
dispatchEventForLegacyPluginEventSystem @ react-dom.development.js:3568
attemptToDispatchEvent @ react-dom.development.js:4267
dispatchEvent @ react-dom.development.js:4189
unstable_runWithPriority @ scheduler.development.js:653
runWithPriority$1 @ react-dom.development.js:11039
discreteUpdates$1 @ react-dom.development.js:21887
discreteUpdates @ react-dom.development.js:806
dispatchDiscreteEvent @ react-dom.development.js:4168
VM10:2 Uncaught ReferenceError: process is not defined
at Object.4043 (:2:13168)
at r (:2:306599)
at Object.8048 (:2:9496)
at r (:2:306599)
at Object.8641 (:2:1379)
at r (:2:306599)
at :2:315627
at :2:324225
at :2:324229
at HTMLIFrameElement.e.onload (index.js:1:1)
```

this should not exist on browser, right?

Reproduziere den Fehler aus dem geklonten Repository und beginne dann mit App.js bei doTranscode sowie dem im Report gezeigten createFFmpeg.js FS stack. Verfolge den browserseitigen Fehler im Zusammenhang mit dem undefinierten process-Wert. Als erledigt gilt die Aufgabe, wenn das Beispiel im Browser läuft und der gemeldete Fehler bei der FS-Operation nicht mehr auftritt.

Vom Indexierungsmodell aus dem Issue-Text verfasst.