Fix HLS writing an incomplete init segment for sparse segments, improve decoder config validation, fix getFirstTimestamp() for Inputs with zero-packet tracks, allow zero-track muxing for some formats that allow it, add new track metadata that allows you to specify the decoder config early (enables zero-packet tracks), fix trafIndices in sparse fragmented MP4s, fix assertion errors in MPEG-TS demuxer

src/wave/wave-muxer.ts

@@ -48,7 +48,18 @@ export class WaveMuxer extends Muxer {
 		this.writer = await this.output._getRootWriter(false);
 		this.riffWriter = new RiffWriter(this.writer);
 
-		// No writing needed here - we'll write the header with the first sample
+		// If the track already tells us everything we need, we can write the header right now. Otherwise, we'll write
+		// it with the first sample.
+		const track = this.output.tracks[0];
+		assert(track?.isAudioTrack());
+
+		if (track.metadata.decoderConfig) {
+			validateAudioChunkMetadata({ decoderConfig: track.metadata.decoderConfig }, track.source._codec);
+
+			this.writeHeader(track, track.metadata.decoderConfig);
+			this.sampleRate = track.metadata.decoderConfig.sampleRate;
+			this.headerWritten = true;
+		}
 
 		release();
 	}
@@ -70,7 +81,7 @@ export class WaveMuxer extends Muxer {
 
 		try {
 			if (!this.headerWritten) {
-				validateAudioChunkMetadata(meta);
+				validateAudioChunkMetadata(meta, track.source._codec);
 
 				assert(meta);
 				assert(meta.decoderConfig);
@@ -341,6 +352,13 @@ export class WaveMuxer extends Muxer {
 	async finalize() {
 		const release = await this.mutex.acquire();
 
+		if (!this.headerWritten) {
+			throw new Error(
+				'Cannot finalize an empty WAVE file: no packets were added and the track specified no decoderConfig in'
+				+ ' its metadata, so there\'s no telling what the file should look like.',
+			);
+		}
+
 		const endPos = this.writer.getPos();
 
 		if (this.isRf64) {