Add Firefox120 handler (#295)

src/Device.ts

@@ -11,6 +11,7 @@ import { Chrome74 } from './handlers/Chrome74';
 import { Chrome70 } from './handlers/Chrome70';
 import { Chrome67 } from './handlers/Chrome67';
 import { Chrome55 } from './handlers/Chrome55';
+import { Firefox120 } from './handlers/Firefox120';
 import { Firefox60 } from './handlers/Firefox60';
 import { Safari12 } from './handlers/Safari12';
 import { Safari11 } from './handlers/Safari11';
@@ -29,6 +30,7 @@ export type BuiltinHandlerName =
 	| 'Chrome70'
 	| 'Chrome67'
 	| 'Chrome55'
+	| 'Firefox120'
 	| 'Firefox60'
 	| 'Safari12'
 	| 'Safari11'
@@ -140,7 +142,9 @@ export function detectDevice(): BuiltinHandlerName | undefined {
 			return 'Chrome55';
 		}
 		// Firefox.
-		else if (isFirefox && !isIOS && browserVersion >= 60) {
+		else if (isFirefox && !isIOS && browserVersion >= 120) {
+			return 'Firefox120';
+		} else if (isFirefox && !isIOS && browserVersion >= 60) {
 			return 'Firefox60';
 		}
 		// Firefox on iOS (so Safari).
@@ -308,6 +312,11 @@ export class Device {
 					break;
 				}
 
+				case 'Firefox120': {
+					this._handlerFactory = Firefox120.createFactory();
+					break;
+				}
+
 				case 'Firefox60': {
 					this._handlerFactory = Firefox60.createFactory();
 					break;

src/handlers/Chrome111.ts

@@ -328,17 +328,11 @@ export class Chrome111 extends HandlerInterface {
 		logger.debug('send() [kind:%s, track.id:%s]', track.kind, track.id);
 
 		if (encodings && encodings.length > 1) {
-			encodings.forEach((encoding, idx: number) => {
-				encoding.rid = `r${idx}`;
-			});
-
 			// Set rid and verify scalabilityMode in each encoding.
 			// NOTE: Even if WebRTC allows different scalabilityMode (different number
 			// of temporal layers) per simulcast stream, we need that those are the
 			// same in all them, so let's pick up the highest value.
 			// NOTE: If scalabilityMode is not given, Chrome will use L1T3.
-
-			let nextRid = 1;
 			let maxTemporalLayers = 1;
 
 			for (const encoding of encodings) {
@@ -351,10 +345,10 @@ export class Chrome111 extends HandlerInterface {
 				}
 			}
 
-			for (const encoding of encodings) {
-				encoding.rid = `r${nextRid++}`;
+			encodings.forEach((encoding, idx: number) => {
+				encoding.rid = `r${idx}`;
 				encoding.scalabilityMode = `L1T${maxTemporalLayers}`;
-			}
+			});
 		}
 
 		const sendingRtpParameters: RtpParameters = utils.clone<RtpParameters>(