From 87ed3a1934edc03f194fc727c3c187220199e966 Mon Sep 17 00:00:00 2001
From: Vanilagy <1696106+Vanilagy@users.noreply.github.com>
Date: Thu, 12 Mar 2026 21:43:14 +0100
Subject: [PATCH] Fix faulty MPEG-2 detection (fixes #322)

---
 src/input-format.ts            | 2 +-
 src/mpeg-ts/mpeg-ts-demuxer.ts | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/input-format.ts b/src/input-format.ts
index ed09428..5506af8 100644
--- a/src/input-format.ts
+++ b/src/input-format.ts
@@ -530,7 +530,7 @@ export class MpegTsInputFormat extends InputFormat {
 		} else if (bytes[0] === 0x47 && bytes[TS_PACKET_SIZE + 16] === 0x47) {
 			// MPEG-TS with Forward Error Correction
 			return true;
-		} else if (bytes[4] === 0x47 && bytes[4 + TS_PACKET_SIZE] === 0x47) {
+		} else if (bytes[4] === 0x47 && bytes[4 + TS_PACKET_SIZE + 4] === 0x47) {
 			// MPEG-2-TS (DVHS)
 			return true;
 		}
diff --git a/src/mpeg-ts/mpeg-ts-demuxer.ts b/src/mpeg-ts/mpeg-ts-demuxer.ts
index 253e8de..be61c08 100644
--- a/src/mpeg-ts/mpeg-ts-demuxer.ts
+++ b/src/mpeg-ts/mpeg-ts-demuxer.ts
@@ -161,10 +161,10 @@ export class MpegTsDemuxer extends Demuxer {
 				// MPEG-TS with Forward Error Correction
 				this.packetOffset = 0;
 				this.packetStride = TS_PACKET_SIZE + 16;
-			} else if (startingBytes[4] === 0x47 && startingBytes[4 + TS_PACKET_SIZE] === 0x47) {
+			} else if (startingBytes[4] === 0x47 && startingBytes[4 + TS_PACKET_SIZE + 4] === 0x47) {
 				// MPEG-2-TS (DVHS)
 				this.packetOffset = 4;
-				this.packetStride = TS_PACKET_SIZE;
+				this.packetStride = TS_PACKET_SIZE + 4;
 			} else {
 				throw new Error('Unreachable.');
 			}