From 94b797e227cb581a64f462e578310a8e75a4a6eb Mon Sep 17 00:00:00 2001
From: Vanilagy <1696106+Vanilagy@users.noreply.github.com>
Date: Sat, 3 May 2025 21:43:29 +0200
Subject: [PATCH] TEMP timestamp iterator bugfix

---
 dev/demux.html    | 67 +++++++++++++++++++++++++++++++++++++++++++++++
 src/media-sink.ts | 11 +++++---
 todo.txt          |  3 ++-
 3 files changed, 77 insertions(+), 4 deletions(-)

diff --git a/dev/demux.html b/dev/demux.html
index f4d059d..cff08c4 100644
--- a/dev/demux.html
+++ b/dev/demux.html
@@ -16,6 +16,72 @@
 			source
 		});
 
+		/*
+		const timestamps = [
+			4.16,
+			4.266666666666667,
+			4.373333333333333,
+			4.48,
+			4.586666666666667,
+			4.693333333333333,
+			4.8,
+			4.906666666666666,
+			5.013333333333334,
+			5.12,
+			5.226666666666667,
+			5.333333333333333,
+			5.4399999999999995,
+			5.546666666666667,
+			5.653333333333333,
+			5.76,
+			5.866666666666666,
+			5.973333333333333,
+			6.08,
+			6.186666666666666,
+			6.293333333333333,
+			6.4,
+			6.506666666666666,
+			6.613333333333333,
+			6.72,
+			6.826666666666666,
+			6.933333333333334,
+			7.039999999999999,
+			7.1466666666666665,
+			7.253333333333333
+		];
+		*/
+		const timestamps = [];
+		const videoTrack = await input.getPrimaryVideoTrack();
+
+		const packetSink = new Metamuxer.EncodedPacketSink(videoTrack);
+		for await (const packet of packetSink.packets()) {
+			if (packet.timestamp >= 1) {
+				break;
+			}
+
+			timestamps.push(packet.timestamp);
+		}
+
+		timestamps.sort((a, b) => a-b)
+
+		console.log(timestamps);
+		//return;
+		/*
+		const sink = new Metamuxer.EncodedPacketSink(videoTrack);
+		for await (const packet of sink.packets()) {
+			console.log(packet.sequenceNumber);
+		}
+		*/
+
+		
+		const sink = new Metamuxer.CanvasSink(videoTrack, { width: 320 });
+
+		for await (const wrappedCanvas of sink.canvasesAtTimestamps(timestamps)) {
+			console.log(wrappedCanvas);
+		}
+			
+
+		/*
 		const output = new Metamuxer.Output({
 			format: new Metamuxer.Mp3OutputFormat(),
 			target: new Metamuxer.BufferTarget()
@@ -49,6 +115,7 @@
 
 		console.log(output.target.buffer)
 		download(new Blob([output.target.buffer]), 'converted.mp3');
+		*/
 
 
 		/*
diff --git a/src/media-sink.ts b/src/media-sink.ts
index dd99777..7e78e7f 100644
--- a/src/media-sink.ts
+++ b/src/media-sink.ts
@@ -526,6 +526,8 @@ export abstract class BaseMediaSampleSink<
 					continue;
 				}
 
+				// console.log('target', targetPacket);
+
 				const keyPacket = await packetSink.getKeyPacket(timestamp);
 				if (!keyPacket) {
 					pushToQueue(null);
@@ -533,15 +535,17 @@ export abstract class BaseMediaSampleSink<
 				}
 
 				if (lastPacket && targetPacket.sequenceNumber < lastPacket.sequenceNumber) {
-					// We're going back in time with this one, let's flush and reset to an clean state
+					// console.log('FLUSH?', lastPacket, targetPacket.sequenceNumber, lastPacket.sequenceNumber);
+					// We're going back in time with this one, let's flush and reset to a clean state
 					await decoder.flush();
 					timestampsOfInterest.length = 0;
 				}
 
 				if (
 					lastKeyPacket
-					&& keyPacket.sequenceNumber === lastKeyPacket.sequenceNumber
-					&& targetPacket.timestamp >= lastPacket!.timestamp
+					&& keyPacket.sequenceNumber === lastKeyPacket.sequenceNumber // => they're the same packet
+					// && targetPacket.timestamp >= lastPacket!.timestamp
+					&& targetPacket.sequenceNumber >= lastPacket!.sequenceNumber
 				) {
 					assert(lastPacket);
 
@@ -558,6 +562,7 @@ export abstract class BaseMediaSampleSink<
 						timestampsOfInterest.push(targetPacket.timestamp);
 					}
 				} else {
+					// console.log('==== RESET');
 					// The key packet has changed
 					lastKeyPacket = keyPacket;
 					lastPacket = keyPacket;
diff --git a/todo.txt b/todo.txt
index 0bb2534..adfe1d4 100644
--- a/todo.txt
+++ b/todo.txt
@@ -1,3 +1,4 @@
 - https://github.com/Vanilagy/mp4-muxer/issues/83 tell him it's possible now
 - textsubtitlesource, chunked piping
-- More efficient MP3 loading when reading sequentially
\ No newline at end of file
+- More efficient MP3 loading when reading sequentially
+- toCanvasImageSource might return a new videoframe; how to handle this?
\ No newline at end of file