Set discontinuity_indicator to 1 for the first packet

dev/demux.html

@@ -14,11 +14,11 @@
 			source: new Mediabunny.BufferSource(await file.arrayBuffer()),
 		});
 
-		const track = await input.getPrimaryAudioTrack();
+		const track = await input.getPrimaryVideoTrack();
 		const sink = new Mediabunny.EncodedPacketSink(track);
 
 		for await (const packet of sink.packets()) {
-			console.log(packet.timestamp, packet.duration, packet.type);
+			//console.log(packet.timestamp, packet.duration, packet.type);
 		}
 
 		/*

src/mpeg-ts/mpeg-ts-demuxer.ts

@@ -638,10 +638,6 @@ const readPesPacketHeader = (section: Section): PesPacketHeader | null => {
 
 	bitstream.skipBits(14);
 
-	if (ptsDtsFlags !== 0b10 && ptsDtsFlags !== 0b11) {
-		return null; // Support only timestamped packets
-	}
-
 	let pts = 0;
 	if (ptsDtsFlags === 0b10 || ptsDtsFlags === 0b11) {
 		bitstream.skipBits(4);
@@ -651,7 +647,10 @@ const readPesPacketHeader = (section: Section): PesPacketHeader | null => {
 		bitstream.skipBits(1);
 		pts += bitstream.readBits(15);
 	} else {
-		return null; // Support only timestamped packets
+		throw new Error(
+			'PES packets without PTS are not currently supported. If you think this file should be supported,'
+			+ ' please report it.',
+		);
 	}
 
 	return {

src/mpeg-ts/mpeg-ts-muxer.ts

@@ -52,6 +52,7 @@ type MpegTsTrackData = {
 	hevcDecoderConfig: HevcDecoderConfigurationRecord | null;
 	adtsHeader: Uint8Array | null;
 	adtsHeaderBitstream: Bitstream | null;
+	firstPacketWritten: boolean;
 };
 
 type QueuedPacket = {
@@ -128,6 +129,7 @@ export class MpegTsMuxer extends Muxer {
 			hevcDecoderConfig: null,
 			adtsHeader: null,
 			adtsHeaderBitstream: null,
+			firstPacketWritten: false,
 		};
 
 		this.trackDatas.push(newTrackData);
@@ -168,6 +170,7 @@ export class MpegTsMuxer extends Muxer {
 			hevcDecoderConfig: null,
 			adtsHeader: null,
 			adtsHeaderBitstream: null,
+			firstPacketWritten: false,
 		};
 
 		this.trackDatas.push(newTrackData);
@@ -518,18 +521,19 @@ export class MpegTsMuxer extends Muxer {
 
 		const totalLength = this.pesHeaderBuffer.length + queuedPacket.data.length;
 		let offset = 0;
-		let isFirst = true;
+		let isFirstTsPacket = true;
 
 		while (offset < totalLength) {
-			const pusi = isFirst;
+			const pusi = isFirstTsPacket;
 			const remainingData = totalLength - offset;
 
-			const needsRandomAccessIndicator = isFirst && queuedPacket.isKeyframe;
+			const randomAccessIndicator = isFirstTsPacket && queuedPacket.isKeyframe;
+			const discontinuityIndicator = isFirstTsPacket && !trackData.firstPacketWritten;
 			const basePaddingNeeded = Math.max(0, 184 - remainingData);
 
 			let adaptationFieldSize: number;
-			if (needsRandomAccessIndicator) {
+			if (randomAccessIndicator || discontinuityIndicator) {
-				// Random access indicator requires at least 2 bytes
+				// We need at least two bytes
 				adaptationFieldSize = Math.max(2, basePaddingNeeded);
 			} else {
 				adaptationFieldSize = basePaddingNeeded;
@@ -543,7 +547,9 @@ export class MpegTsMuxer extends Muxer {
 					buf[0] = 0; // adaptation_field_length
 				} else {
 					buf[0] = adaptationFieldSize - 1; // adaptation_field_length
-					buf[1] = Number(needsRandomAccessIndicator) << 6; // flags (random_access_indicator in bit 6)
+					buf[1]
+						= (Number(discontinuityIndicator) << 7) // discontinuity_indicator
+							| (Number(randomAccessIndicator) << 6); // random_access_indicator
 					buf.fill(0xFF, 2, adaptationFieldSize); // stuffing_bytes
 				}
 
@@ -569,8 +575,10 @@ export class MpegTsMuxer extends Muxer {
 			this.writeTsPacket(trackData.pid, pusi, adaptationField, payload);
 
 			offset += payloadSize;
-			isFirst = false;
+			isFirstTsPacket = false;
 		}
+
+		trackData.firstPacketWritten = true;
 	}
 
 	private writeTsPacket(