From 3668cad724a77d40af1f1f911919d96ef74201f5 Mon Sep 17 00:00:00 2001
From: feyris-tan <4116042+feyris-tan@users.noreply.github.com>
Date: Sun, 23 Nov 2025 21:23:41 +0100
Subject: [PATCH] Patch overdumped MPEG-DASH segments.

---
 skyscraper8/DvbNip/DvbNipUtilities.cs         | 29 ++++++++++++++++---
 skyscraper8/Ietf/FLUTE/FluteListener.cs       |  9 ++++--
 .../Ietf/{ => FLUTE}/FluteListenerMime.cs     |  3 +-
 skyscraper8/Ietf/FLUTE/FluteListenerStream.cs | 22 ++++++++++++--
 .../Skyscraper/Scraper/SkyscraperContext.cs   |  7 ++++-
 5 files changed, 59 insertions(+), 11 deletions(-)
 rename skyscraper8/Ietf/{ => FLUTE}/FluteListenerMime.cs (90%)

diff --git a/skyscraper8/DvbNip/DvbNipUtilities.cs b/skyscraper8/DvbNip/DvbNipUtilities.cs
index 109bbe8..c0c49ae 100644
--- a/skyscraper8/DvbNip/DvbNipUtilities.cs
+++ b/skyscraper8/DvbNip/DvbNipUtilities.cs
@@ -1,13 +1,14 @@
-using System;
+using log4net;
+using MimeKit;
+using skyscraper5.Skyscraper.IO;
+using skyscraper8.Ietf.FLUTE;
+using System;
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Xml.Serialization;
-using MimeKit;
-using skyscraper5.Skyscraper.IO;
-using skyscraper8.Ietf.FLUTE;
 
 namespace skyscraper8.DvbNip
 {
@@ -15,6 +16,7 @@ namespace skyscraper8.DvbNip
 	{
 		private DvbNipUtilities() { }
 
+		private static readonly ILog logger = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType.Name);
 		private static XmlSerializer multicastGatewayConfigurationXmlSerializer;
 
 		public static bool IsXml(Stream s)
@@ -225,5 +227,24 @@ namespace skyscraper8.DvbNip
 			}
 			throw new NotImplementedException();
 		}
+
+		public static FluteListener PatchMpegDashSegment(FluteListener listener)
+		{
+			Stream stream = listener.ToStream();
+			stream.Position = stream.Length - 1;
+			byte readUInt8 = stream.ReadUInt8();
+			if (readUInt8 != 0)
+				return listener;
+
+			logger.WarnFormat("MPEG-DASH segment {0} is overdumped. It will be patched to become playable.", listener.FileAssociation.ContentLocation);
+			stream.Position = stream.Length - 1;
+			while (stream.ReadUInt8() == 0)
+			{
+				stream.Position -= 2;
+			}
+
+			listener.TrimmedLength = stream.Position;
+			return listener;
+		}
 	}
 }
diff --git a/skyscraper8/Ietf/FLUTE/FluteListener.cs b/skyscraper8/Ietf/FLUTE/FluteListener.cs
index 1c232c4..23d161f 100644
--- a/skyscraper8/Ietf/FLUTE/FluteListener.cs
+++ b/skyscraper8/Ietf/FLUTE/FluteListener.cs
@@ -119,7 +119,7 @@ namespace skyscraper8.Ietf.FLUTE
 
 		}
 
-		internal bool IsComplete()
+		internal virtual bool IsComplete()
 		{
 			if (_disabled)
 				return false;
@@ -165,7 +165,11 @@ namespace skyscraper8.Ietf.FLUTE
 				blockPayloads.Sort(new FluteBlockComparer());
 				level1 = new FluteListenerStream(blockPayloads);
 			}
-			
+			if (TrimmedLength.HasValue)
+			{
+				level1.SetLength(TrimmedLength.Value);
+			}
+
 			if (FileAssociation != null)
 			{
 				switch(FileAssociation.ContentEncoding)
@@ -288,5 +292,6 @@ namespace skyscraper8.Ietf.FLUTE
 		}
 
 		public double LastReportedProgress { get; internal set; }
+		public long? TrimmedLength { get; set; }
 	}
 }
diff --git a/skyscraper8/Ietf/FluteListenerMime.cs b/skyscraper8/Ietf/FLUTE/FluteListenerMime.cs
similarity index 90%
rename from skyscraper8/Ietf/FluteListenerMime.cs
rename to skyscraper8/Ietf/FLUTE/FluteListenerMime.cs
index db4b936..f8c9ba1 100644
--- a/skyscraper8/Ietf/FluteListenerMime.cs
+++ b/skyscraper8/Ietf/FLUTE/FluteListenerMime.cs
@@ -4,9 +4,8 @@ using System.Linq;
 using System.Net;
 using System.Text;
 using System.Threading.Tasks;
-using skyscraper8.Ietf.FLUTE;
 
-namespace skyscraper8.Ietf
+namespace skyscraper8.Ietf.FLUTE
 {
 	internal class FluteListenerMime : FluteListener
 	{
diff --git a/skyscraper8/Ietf/FLUTE/FluteListenerStream.cs b/skyscraper8/Ietf/FLUTE/FluteListenerStream.cs
index 64c28c4..d57efd3 100644
--- a/skyscraper8/Ietf/FLUTE/FluteListenerStream.cs
+++ b/skyscraper8/Ietf/FLUTE/FluteListenerStream.cs
@@ -118,9 +118,17 @@ namespace skyscraper8.Ietf.FLUTE
 			return currentPosition;
 		}
 
+		private bool _isLengthLimited;
+		private long _limitedLength;
 		public override void SetLength(long value)
 		{
-			throw new NotSupportedException("Can't modify the length of a ModuleInfo");
+			if (value > myModuleLength)
+			{
+				throw new ArgumentOutOfRangeException(String.Format("Argument must be between 0 and {0}", myModuleLength));
+			}
+
+			_limitedLength = value;
+			_isLengthLimited = true;
 		}
 
 		public override void Write(byte[] buffer, int offset, int count)
@@ -131,7 +139,17 @@ namespace skyscraper8.Ietf.FLUTE
 		public override bool CanRead => true;
 		public override bool CanSeek => true;
 		public override bool CanWrite => false;
-		public override long Length => myModuleLength;
+
+		public override long Length
+		{
+			get
+			{
+				if (_isLengthLimited)
+					return _limitedLength;
+				else
+					return myModuleLength;
+			}
+		}
 
 		public override long Position
 		{
diff --git a/skyscraper8/Skyscraper/Scraper/SkyscraperContext.cs b/skyscraper8/Skyscraper/Scraper/SkyscraperContext.cs
index bd98081..6ed2b04 100644
--- a/skyscraper8/Skyscraper/Scraper/SkyscraperContext.cs
+++ b/skyscraper8/Skyscraper/Scraper/SkyscraperContext.cs
@@ -86,7 +86,6 @@ using skyscraper8.GS;
 using skyscraper8.GSE;
 using skyscraper8.GSE.GSE;
 using skyscraper8.Ieee802_1AB;
-using skyscraper8.Ietf;
 using skyscraper8.InteractionChannel.Model;
 using skyscraper8.InteractionChannel.Model2;
 using skyscraper8.InteractionChannel.Model2.Descriptors;
@@ -2778,6 +2777,12 @@ namespace skyscraper5.Skyscraper.Scraper
 					knownNipSegments[ep] = new List<string>();
 				knownNipSegments[ep].Add(listener.FileAssociation.ContentLocation);
 			}
+
+			if (extension.Equals(".m4s"))
+			{
+				listener = DvbNipUtilities.PatchMpegDashSegment(listener);
+			}
+
 	        ObjectStorage.DvbNipFileArrival(carrier, listener);
         }