Add timestampBase option for live MediaStreamTrack sources

src/muxer.ts

@@ -15,13 +15,6 @@ export abstract class Muxer {
 	output: Output;
 	mutex = new AsyncMutex();
 
-	/**
-	 * This field is used to synchronize multiple MediaStreamTracks. They use the same time coordinate system across
-	 * tracks, and to ensure correct audio-video sync, we must use the same offset for all of them. The reason an offset
-	 * is needed at all is because the timestamps typically don't start at zero.
-	 */
-	firstMediaStreamTimestamp: number | null = null;
-
 	constructor(output: Output) {
 		this.output = output;
 	}