From a9cec387d4f5b901bd8dfc631daf903ff56c666d Mon Sep 17 00:00:00 2001
From: Vanilagy <1696106+Vanilagy@users.noreply.github.com>
Date: Sun, 10 Aug 2025 19:55:21 +0200
Subject: [PATCH] Extract insertSorted function

---
 src/isobmff/isobmff-demuxer.ts   | 20 +++++---------------
 src/matroska/matroska-demuxer.ts | 23 ++++-------------------
 src/media-sink.ts                | 15 +++------------
 src/misc.ts                      |  6 ++++++
 4 files changed, 18 insertions(+), 46 deletions(-)

diff --git a/src/isobmff/isobmff-demuxer.ts b/src/isobmff/isobmff-demuxer.ts
index c0b3a2d..20bcf42 100644
--- a/src/isobmff/isobmff-demuxer.ts
+++ b/src/isobmff/isobmff-demuxer.ts
@@ -55,6 +55,7 @@ import {
 	roundToMultiple,
 	normalizeRotation,
 	Bitstream,
+	insertSorted,
 } from '../misc';
 import { EncodedPacket, PLACEHOLDER_DATA } from '../packet';
 import { Reader } from '../reader';
@@ -1624,12 +1625,7 @@ export class IsobmffDemuxer extends Demuxer {
 
 				this.readContiguousBoxes(boxInfo.contentSize);
 
-				const insertionIndex = binarySearchLessOrEqual(
-					this.fragments,
-					this.currentFragment.moofOffset,
-					x => x.moofOffset,
-				);
-				this.fragments.splice(insertionIndex + 1, 0, this.currentFragment);
+				insertSorted(this.fragments, this.currentFragment, x => x.moofOffset);
 
 				// Compute the byte range of the sample data in this fragment, so we can load the whole fragment at once
 				for (const [, trackData] of this.currentFragment.trackData) {
@@ -1661,21 +1657,15 @@ export class IsobmffDemuxer extends Demuxer {
 					if (trackData) {
 						// We know there is sample data for this track in this fragment, so let's add it to the
 						// track's fragments:
-						const insertionIndex = binarySearchLessOrEqual(
-							this.currentTrack.fragments,
-							this.currentFragment.moofOffset,
-							x => x.moofOffset,
-						);
-						this.currentTrack.fragments.splice(insertionIndex + 1, 0, this.currentFragment);
+						insertSorted(this.currentTrack.fragments, this.currentFragment, x => x.moofOffset);
 
 						const hasKeyFrame = trackData.firstKeyFrameTimestamp !== null;
 						if (hasKeyFrame) {
-							const insertionIndex = binarySearchLessOrEqual(
+							insertSorted(
 								this.currentTrack.fragmentsWithKeyFrame,
-								this.currentFragment.moofOffset,
+								this.currentFragment,
 								x => x.moofOffset,
 							);
-							this.currentTrack.fragmentsWithKeyFrame.splice(insertionIndex + 1, 0, this.currentFragment);
 						}
 
 						const { currentFragmentState } = this.currentTrack;
diff --git a/src/matroska/matroska-demuxer.ts b/src/matroska/matroska-demuxer.ts
index 8d61174..adafd0b 100644
--- a/src/matroska/matroska-demuxer.ts
+++ b/src/matroska/matroska-demuxer.ts
@@ -38,6 +38,7 @@ import {
 	binarySearchLessOrEqual,
 	COLOR_PRIMARIES_MAP_INVERSE,
 	findLastIndex,
+	insertSorted,
 	isIso639Dash2LanguageCode,
 	last,
 	MATRIX_COEFFICIENTS_MAP_INVERSE,
@@ -570,32 +571,16 @@ export class MatroskaDemuxer extends Demuxer {
 			trackData.endTimestamp = lastBlock.timestamp + lastBlock.duration;
 
 			if (track) {
-				const insertionIndex = binarySearchLessOrEqual(
-					track.clusters,
-					cluster.elementStartPos,
-					x => x.elementStartPos,
-				);
-				track.clusters.splice(insertionIndex + 1, 0, cluster);
+				insertSorted(track.clusters, cluster, x => x.elementStartPos);
 
 				const hasKeyFrame = trackData.firstKeyFrameTimestamp !== null;
 				if (hasKeyFrame) {
-					const insertionIndex = binarySearchLessOrEqual(
-						track.clustersWithKeyFrame,
-						cluster.elementStartPos,
-						x => x.elementStartPos,
-					);
-					track.clustersWithKeyFrame.splice(insertionIndex + 1, 0, cluster);
+					insertSorted(track.clustersWithKeyFrame, cluster, x => x.elementStartPos);
 				}
 			}
 		}
 
-		const insertionIndex = binarySearchLessOrEqual(
-			segment.clusters,
-			elementStartPos,
-			x => x.elementStartPos,
-		);
-		segment.clusters.splice(insertionIndex + 1, 0, cluster);
-
+		insertSorted(segment.clusters, cluster, x => x.elementStartPos);
 		this.currentCluster = null;
 
 		return cluster;
diff --git a/src/media-sink.ts b/src/media-sink.ts
index 09404a4..df97305 100644
--- a/src/media-sink.ts
+++ b/src/media-sink.ts
@@ -17,6 +17,7 @@ import {
 	CallSerializer,
 	getInt24,
 	getUint24,
+	insertSorted,
 	isSafari,
 	last,
 	mapAsyncGenerator,
@@ -799,12 +800,7 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 						this.sampleQueue.length = 0;
 					}
 
-					const insertionIndex = binarySearchLessOrEqual(
-						this.sampleQueue,
-						sample.timestamp,
-						x => x.timestamp,
-					);
-					this.sampleQueue.splice(insertionIndex + 1, 0, sample);
+					insertSorted(this.sampleQueue, sample, x => x.timestamp);
 				} else {
 					// Assign it the next earliest timestamp from the input. We do this because browsers, by spec, are
 					// required to emit decoded frames in presentation order *while* retaining the timestamp of their
@@ -858,12 +854,7 @@ class VideoDecoderWrapper extends DecoderWrapper<VideoSample> {
 			assert(this.decoder);
 
 			if (!isSafari()) {
-				const insertionIndex = binarySearchLessOrEqual(
-					this.inputTimestamps,
-					packet.timestamp,
-					x => x,
-				);
-				this.inputTimestamps.splice(insertionIndex + 1, 0, packet.timestamp);
+				insertSorted(this.inputTimestamps, packet.timestamp, x => x);
 			}
 
 			this.decoder.decode(packet.toEncodedVideoChunk());
diff --git a/src/misc.ts b/src/misc.ts
index 6edc9ad..079ab5e 100644
--- a/src/misc.ts
+++ b/src/misc.ts
@@ -292,6 +292,12 @@ export const binarySearchLessOrEqual = <T>(arr: T[], key: number, valueGetter: (
 	return ans;
 };
 
+/** Assumes the array is already sorted. */
+export const insertSorted = <T>(arr: T[], item: T, valueGetter: (x: T) => number) => {
+	const insertionIndex = binarySearchLessOrEqual(arr, valueGetter(item), valueGetter);
+	arr.splice(insertionIndex + 1, 0, item); // This even behaves correctly for the -1 case
+};
+
 export const promiseWithResolvers = <T = void>() => {
 	let resolve: (value: T) => void;
 	let reject: (reason: unknown) => void;