Add support for unsized sources, add ReadableStreamSource, fix WAVE packet lookup

src/mp3/mp3-demuxer.ts

@@ -47,7 +47,7 @@ export class Mp3Demuxer extends Demuxer {
 	async readMetadata() {
 		return this.metadataPromise ??= (async () => {
 			// Keep loading until we find the first frame header
-			while (!this.firstFrameHeader && this.lastLoadedPos < this.reader.fileSize) {
+			while (!this.firstFrameHeader && !this.lastSampleLoaded) {
 				await this.advanceReader();
 			}
 
@@ -211,7 +211,10 @@ class Mp3AudioTrackBacking implements InputAudioTrackBacking {
 		} else {
 			let slice = this.demuxer.reader.requestSlice(rawSample.dataStart, rawSample.dataSize);
 			if (slice instanceof Promise) slice = await slice;
-			assert(slice);
+
+			if (!slice) {
+				return null; // Data didn't fit into the rest of the file
+			}
 
 			data = readBytes(slice, rawSample.dataSize);
 		}

src/mp3/mp3-reader.ts

@@ -22,20 +22,20 @@ export const readId3 = (slice: FileSlice) => {
 	return { size };
 };
 
-export const readNextFrameHeader = async (reader: Reader, startPos: number, until: number): Promise<{
+export const readNextFrameHeader = async (reader: Reader, startPos: number, until: number | null): Promise<{
 	header: FrameHeader;
 	startPos: number;
 } | null> => {
 	let currentPos = startPos;
 
-	while (currentPos < until) {
+	while (until === null || currentPos < until) {
 		let slice = reader.requestSlice(currentPos, FRAME_HEADER_SIZE);
 		if (slice instanceof Promise) slice = await slice;
 		if (!slice) break;
 
 		const word = readU32Be(slice);
 
-		const result = readFrameHeader(word, reader.fileSize - currentPos);
+		const result = readFrameHeader(word, reader.fileSize !== null ? reader.fileSize - currentPos : null);
 		if (result.header) {
 			return { header: result.header, startPos: currentPos };
 		}