From 58d73b7de3614aed1308fc57d9b1a51e61abd9eb Mon Sep 17 00:00:00 2001
From: Vanilagy <1696106+Vanilagy@users.noreply.github.com>
Date: Mon, 22 Dec 2025 23:20:51 +0100
Subject: [PATCH] Make more use of sequenceNumber in getNextPacket

---
 src/adts/adts-demuxer.ts |  8 ++------
 src/flac/flac-demuxer.ts |  4 ++++
 src/mp3/mp3-demuxer.ts   | 10 +++-------
 src/wave/wave-demuxer.ts |  6 +++++-
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/src/adts/adts-demuxer.ts b/src/adts/adts-demuxer.ts
index 4a1bbe9..d50cd03 100644
--- a/src/adts/adts-demuxer.ts
+++ b/src/adts/adts-demuxer.ts
@@ -14,7 +14,6 @@ import { PacketRetrievalOptions } from '../media-sink';
 import {
 	assert,
 	AsyncMutex4,
-	binarySearchExact,
 	binarySearchLessOrEqual,
 	Bitstream,
 	ResultValue,
@@ -261,16 +260,13 @@ class AdtsAudioTrackBacking implements InputAudioTrackBacking {
 		using lock = this.demuxer.readingMutex.lock();
 		if (lock.pending) await lock.ready;
 
-		const sampleIndex = binarySearchExact(
-			this.demuxer.loadedSamples,
-			packet.timestamp,
-			x => x.timestamp,
-		);
+		const sampleIndex = packet.sequenceNumber;
 		if (sampleIndex === -1) {
 			throw new Error('Packet was not created from this track.');
 		}
 
 		const nextIndex = sampleIndex + 1;
+
 		// Ensure the next sample exists
 		while (
 			nextIndex >= this.demuxer.loadedSamples.length
diff --git a/src/flac/flac-demuxer.ts b/src/flac/flac-demuxer.ts
index 36b0b80..1c06e73 100644
--- a/src/flac/flac-demuxer.ts
+++ b/src/flac/flac-demuxer.ts
@@ -644,6 +644,10 @@ class FlacAudioTrackBacking implements InputAudioTrackBacking {
 		using lock = this.demuxer.readingMutex.lock();
 		if (lock.pending) await lock.ready;
 
+		if (packet.sequenceNumber < 0) {
+			throw new Error('Packet was not created from this track.');
+		}
+
 		const nextIndex = packet.sequenceNumber + 1;
 		if (
 			this.demuxer.lastSampleLoaded
diff --git a/src/mp3/mp3-demuxer.ts b/src/mp3/mp3-demuxer.ts
index 91e417b..191902c 100644
--- a/src/mp3/mp3-demuxer.ts
+++ b/src/mp3/mp3-demuxer.ts
@@ -15,7 +15,6 @@ import { PacketRetrievalOptions } from '../media-sink';
 import {
 	assert,
 	AsyncMutex4,
-	binarySearchExact,
 	binarySearchLessOrEqual,
 	ResultValue,
 	UNDETERMINED_LANGUAGE,
@@ -318,16 +317,13 @@ class Mp3AudioTrackBacking implements InputAudioTrackBacking {
 		using lock = this.demuxer.readingMutex.lock();
 		if (lock.pending) await lock.ready;
 
-		const sampleIndex = binarySearchExact(
-			this.demuxer.loadedSamples,
-			packet.timestamp,
-			x => x.timestamp,
-		);
-		if (sampleIndex === -1) {
+		const sampleIndex = packet.sequenceNumber;
+		if (sampleIndex < 0) {
 			throw new Error('Packet was not created from this track.');
 		}
 
 		const nextIndex = sampleIndex + 1;
+
 		// Ensure the next sample exists
 		while (
 			nextIndex >= this.demuxer.loadedSamples.length
diff --git a/src/wave/wave-demuxer.ts b/src/wave/wave-demuxer.ts
index d1aab5e..a63ab92 100644
--- a/src/wave/wave-demuxer.ts
+++ b/src/wave/wave-demuxer.ts
@@ -516,7 +516,11 @@ class WaveAudioTrackBacking implements InputAudioTrackBacking {
 		options: PacketRetrievalOptions,
 	): Promise<Yo> {
 		assert(this.demuxer.audioInfo);
-		const packetIndex = Math.round(packet.timestamp * this.demuxer.audioInfo.sampleRate / PACKET_SIZE_IN_FRAMES);
+
+		const packetIndex = packet.sequenceNumber;
+		if (packetIndex < 0) {
+			throw new Error('Packet was not created from this track.');
+		}
 
 		return this.getPacketAtIndex(res, packetIndex + 1, options);
 	}