[WIP] Add majority of logic for HLS reading support

src/mp3/mp3-demuxer.ts

@@ -267,6 +267,10 @@ class Mp3AudioTrackBacking implements InputAudioTrackBacking {
 		};
 	}
 
+	getVariant() {
+		return null;
+	}
+
 	async getDecoderConfig(): Promise<AudioDecoderConfig> {
 		assert(this.demuxer.firstFrameHeader);
 

src/mp3/mp3-reader.ts

@@ -15,6 +15,8 @@ export const readNextMp3FrameHeader = async (reader: Reader, startPos: number, u
 } | null> => {
 	let currentPos = startPos;
 
+	// todo optimize this shit wtf is this
+
 	while (until === null || currentPos < until) {
 		let slice = reader.requestSlice(currentPos, FRAME_HEADER_SIZE);
 		if (slice instanceof Promise) slice = await slice;