add 540p as additional simulcast video layer

Author: fkwp

src/livekit/options.ts

@@ -23,7 +23,7 @@ const defaultLiveKitPublishOptions: TrackPublishDefaults = {
   red: false,
   forceStereo: false,
   simulcast: true,
-  videoSimulcastLayers: [VideoPresets.h180, VideoPresets.h360] as VideoPreset[],
+  videoSimulcastLayers: [VideoPresets.h180, VideoPresets.h360, VideoPresets.h540] as VideoPreset[],
   screenShareEncoding: ScreenSharePresets.h1080fps30.encoding,
   stopMicTrackOnMute: false,
   videoCodec: "h264",