Clean up some code, add new source getting for Input

src/media-sink.ts

@@ -134,13 +134,17 @@ export class EncodedPacketSink {
 	 * Retrieves the track's first packet (in decode order), or null if it has no packets. The first packet is very
 	 * likely to be a key packet, but it doesn't have to be.
 	 */
-	getFirstPacket(options: PacketRetrievalOptions = {}) {
+	async getFirstPacket(options: PacketRetrievalOptions = {}) {
 		validatePacketRetrievalOptions(options);
 
 		if (this._track.input._disposed) {
 			throw new InputDisposedError();
 		}
 
+		if (!this._track.isHydrated) {
+			await this._track.hydrate();
+		}
+
 		return maybeFixPacketType(this._track, this._track._backing.getFirstPacket(options), options);
 	}
 
@@ -169,7 +173,7 @@ export class EncodedPacketSink {
 	 *
 	 * @param timestamp - The timestamp used for retrieval, in seconds.
 	 */
-	getPacket(timestamp: number, options: PacketRetrievalOptions = {}) {
+	async getPacket(timestamp: number, options: PacketRetrievalOptions = {}) {
 		validateTimestamp(timestamp);
 		validatePacketRetrievalOptions(options);
 
@@ -177,6 +181,10 @@ export class EncodedPacketSink {
 			throw new InputDisposedError();
 		}
 
+		if (!this._track.isHydrated) {
+			await this._track.hydrate();
+		}
+
 		return maybeFixPacketType(this._track, this._track._backing.getPacket(timestamp, options), options);
 	}
 
@@ -184,7 +192,7 @@ export class EncodedPacketSink {
 	 * Retrieves the packet following the given packet (in decode order), or null if the given packet is the
 	 * last packet.
 	 */
-	getNextPacket(packet: EncodedPacket, options: PacketRetrievalOptions = {}) {
+	async getNextPacket(packet: EncodedPacket, options: PacketRetrievalOptions = {}) {
 		if (!(packet instanceof EncodedPacket)) {
 			throw new TypeError('packet must be an EncodedPacket.');
 		}
@@ -194,6 +202,10 @@ export class EncodedPacketSink {
 			throw new InputDisposedError();
 		}
 
+		if (!this._track.isHydrated) {
+			await this._track.hydrate();
+		}
+
 		return maybeFixPacketType(this._track, this._track._backing.getNextPacket(packet, options), options);
 	}
 
@@ -216,6 +228,10 @@ export class EncodedPacketSink {
 			throw new InputDisposedError();
 		}
 
+		if (!this._track.isHydrated) {
+			await this._track.hydrate();
+		}
+
 		if (!options.verifyKeyPackets) {
 			return this._track._backing.getKeyPacket(timestamp, options);
 		}
@@ -251,6 +267,10 @@ export class EncodedPacketSink {
 			throw new InputDisposedError();
 		}
 
+		if (!this._track.isHydrated) {
+			await this._track.hydrate();
+		}
+
 		if (!options.verifyKeyPackets) {
 			return this._track._backing.getNextKeyPacket(packet, options);
 		}