Add @mediabunny/flac-encoder extension, clean up some other code, fix incorrect top-level tsconfig

src/conversion.ts

@@ -786,6 +786,12 @@ export class Conversion {
 						+ ' for encoding and decoding AC-3/E-AC-3.',
 					);
 				}
+
+				if (codecs.includes('flac')) {
+					elements.push(
+						'\nThe @mediabunny/flac-encoder extension package provides support for encoding FLAC.',
+					);
+				}
 			} else {
 				elements.push('\nCheck the discardedTracks field for more info.');
 			}

src/flac/flac-muxer.ts

@@ -207,12 +207,6 @@ export class FlacMuxer extends Muxer {
 	): Promise<void> {
 		const release = await this.mutex.acquire();
 
-		validateAudioChunkMetadata(meta);
-
-		assert(meta);
-		assert(meta.decoderConfig);
-		assert(meta.decoderConfig.description);
-
 		try {
 			this.validateAndNormalizeTimestamp(
 				track,
@@ -221,14 +215,16 @@ export class FlacMuxer extends Muxer {
 			);
 
 			if (this.sampleRate === null) {
+				// It's the first packet
+				validateAudioChunkMetadata(meta);
+
+				assert(meta);
+				assert(meta.decoderConfig);
+				assert(meta.decoderConfig.description);
+
 				this.sampleRate = meta.decoderConfig.sampleRate;
-			}
-
-			if (this.channels === null) {
 				this.channels = meta.decoderConfig.numberOfChannels;
-			}
 
-			if (this.bitsPerSample === null) {
 				const descriptionBitstream = new Bitstream(
 					toUint8Array(meta.decoderConfig.description),
 				);
@@ -244,7 +240,7 @@ export class FlacMuxer extends Muxer {
 			}
 
 			const slice = FileSlice.tempFromBytes(packet.data);
-			readBytes(slice, 2);
+			slice.skip(2);
 			const bytes = readBytes(slice, 2);
 			const bitstream = new Bitstream(bytes);
 			const blockSizeOrUncommon = getBlockSizeOrUncommon(bitstream.readBits(4));