Move ChapterInfo into Mpeg4Lib

Author: Mbucari

src/AAXClean/Chapter.cs

@@ -1,4 +1,5 @@
 using AAXClean.FrameFilters;
+using Mpeg4Lib;
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;

src/AAXClean/ChapterInfo.cs

@@ -1,4 +1,5 @@
-using System;
+using Mpeg4Lib;
+using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 

src/AAXClean/ChapterQueue.cs

@@ -2,14 +2,12 @@
 using AAXClean.FrameFilters;
 using AAXClean.FrameFilters.Audio;
 using AAXClean.FrameFilters.Text;
+using Mpeg4Lib;
 using Mpeg4Lib.Boxes;
-using Mpeg4Lib.Chunks;
 using Mpeg4Lib.Util;
 using System;
-using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Text;
 using System.Threading.Tasks;
 
 namespace AAXClean
@@ -41,11 +39,10 @@ public enum SampleRate : int
 
 	public class Mp4File : Mpeg4Lib.Mpeg4File
 	{
-		public ChapterInfo? Chapters { get; set; }
+#pragma warning disable CS0618 // Type or member is obsolete
 		[Obsolete("Use MetadataItems property instead.")]
 		public AppleTags AppleTags  => lazyAppleTags.Value;
 
-#pragma warning disable CS0618 // Type or member is obsolete
 		private readonly Lazy<AppleTags> lazyAppleTags;
 #pragma warning restore CS0618
 
@@ -187,50 +184,6 @@ public Mp4Operation ConvertToMultiMp4aAsync(ChapterInfo userChapters, Action<New
 			return ProcessAudio(TimeSpan.Zero, TimeSpan.MaxValue, continuation, (Moov.TextTrack, chapterFilter));
 		}
 
-		public ChapterInfo? GetChaptersFromMetadata()
-		{
-			TrakBox? textTrak = Moov.TextTrack;
-
-			//Get chapter names from metadata box in chapter track
-			List<string>? chapterNames =
-				textTrak
-				?.GetChild<UdtaBox>()
-				?.GetChild<MetaBox>()
-				?.GetChild<AppleListBox>()
-				?.Children
-				?.OfType<AppleTagBox>()
-				?.Where(b => b.Header.Type == "©nam")
-				?.Select(b => b.Data.ReadAsString())
-				?.ToList();
-
-			if (chapterNames is null) return null;
-
-			List<SttsBox.SampleEntry> sampleTimes = textTrak!.Mdia.Minf.Stbl.Stts.Samples;
-
-			if (sampleTimes.Count != chapterNames.Count) return null;
-
-			var cEntryList = new ChunkEntryList(textTrak).OrderBy(s => s.ChunkOffset).ToList();
-
-			if (cEntryList.Count != chapterNames.Count) return null;
-
-			ChapterInfo chapterInfo = new();
-
-			int subtractNext = 0;
-
-			for (int i = 0; i < chapterNames.Count; i++)
-			{
-				var sif = (int)sampleTimes[i].FrameDelta;
-
-				TimeSpan duration = TimeSpan.FromSeconds(Math.Max(0d, sif + subtractNext) / TimeScale);
-				chapterInfo.AddChapter(chapterNames[(int)cEntryList[i].ChunkIndex], duration);
-				subtractNext = sif < 0 ? sif : 0;
-			}
-
-			Chapters ??= chapterInfo;
-
-			return chapterInfo;
-		}
-
 		protected virtual IChunkReader CreateChunkReader(Stream inputStream, TimeSpan startTime, TimeSpan endTime)
 			=> new ChunkReader(inputStream, startTime, endTime);
 

src/AAXClean/FrameFilters/Audio/MultipartFilterBase.cs

@@ -1,4 +1,5 @@
-using System.IO;
+using Mpeg4Lib;
+using System.IO;
 
 namespace AAXClean
 {

src/AAXClean/Mp4File.cs

@@ -0,0 +1,40 @@
+using Mpeg4Lib.Util;
+using System;
+using System.IO;
+using System.Text;
+
+namespace Mpeg4Lib;
+
+public record Chapter
+{
+	public string Title { get; }
+	public TimeSpan StartOffset { get; }
+	public TimeSpan Duration { get; }
+	public TimeSpan EndOffset { get; }
+	public int RenderSize => 2 + Encoding.UTF8.GetByteCount(Title) + encd.Length;
+	public Chapter(string title, TimeSpan start, TimeSpan duration)
+	{
+		ArgumentNullException.ThrowIfNull(title, nameof(title));
+		Title = title;
+		StartOffset = start;
+		Duration = duration;
+		EndOffset = StartOffset + Duration;
+	}
+
+	public void WriteChapter(Stream output)
+	{
+		byte[] title = Encoding.UTF8.GetBytes(Title);
+
+		output.WriteInt16BE((short)title.Length);
+		output.Write(title);
+		output.Write(encd);
+	}
+	public override string ToString()
+	{
+		return $"{Title} {{{StartOffset} - {EndOffset}}}";
+	}
+
+	//This is constant folr UTF-8 text
+	//https://github.com/FFmpeg/FFmpeg/blob/master/libavformat/movenc.c
+	private static readonly byte[] encd = [0, 0, 0, 0xc, (byte)'e', (byte)'n', (byte)'c', (byte)'d', 0, 0, 1, 0];
+}

src/AAXClean/NewSplitCallback.cs

@@ -0,0 +1,37 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Mpeg4Lib;
+
+public record ChapterInfo : IEnumerable<Chapter>
+{
+	public TimeSpan StartOffset { get; }
+	public TimeSpan EndOffset => Count == 0 ? StartOffset : _chapterList.Max(c => c.EndOffset);
+
+	private readonly List<Chapter> _chapterList = new();
+	public IReadOnlyList<Chapter> Chapters => _chapterList;
+	public int Count => _chapterList.Count;
+	public int RenderSize => _chapterList.Sum(c => c.RenderSize);
+
+	public ChapterInfo(TimeSpan offsetFromBeginning = default) => StartOffset = offsetFromBeginning;
+
+	public void AddChapter(string title, TimeSpan duration)
+	{
+		TimeSpan startTime = Count == 0 ? StartOffset : _chapterList[^1].EndOffset;
+
+		_chapterList.Add(new Chapter(title, startTime, duration));
+	}
+	public void Add(string title, TimeSpan duration) => AddChapter(title, duration);
+
+	public IEnumerator<Chapter> GetEnumerator()
+	{
+		return _chapterList.GetEnumerator();
+	}
+
+	IEnumerator IEnumerable.GetEnumerator()
+	{
+		return GetEnumerator();
+	}
+}

src/Mpeg4Lib/Chapter.cs

@@ -1,4 +1,5 @@
 using Mpeg4Lib.Boxes;
+using Mpeg4Lib.Chunks;
 using Mpeg4Lib.Util;
 using System;
 using System.Collections.Generic;
@@ -11,6 +12,7 @@ namespace Mpeg4Lib;
 
 public class Mpeg4File : IDisposable
 {
+	public ChapterInfo? Chapters { get; set; }
 	public Stream InputStream { get; }
 	public FtypBox Ftyp { get; set; }
 	public MoovBox Moov { get; }
@@ -230,6 +232,50 @@ public static async Task RelocateMoovToBeginningAsync(string mp4FilePath, Progre
 		}
 	}
 
+	public ChapterInfo? GetChaptersFromMetadata()
+	{
+		TrakBox? textTrak = Moov.TextTrack;
+
+		//Get chapter names from metadata box in chapter track
+		List<string>? chapterNames =
+			textTrak
+			?.GetChild<UdtaBox>()
+			?.GetChild<MetaBox>()
+			?.GetChild<AppleListBox>()
+			?.Children
+			?.OfType<AppleTagBox>()
+			?.Where(b => b.Header.Type == "©nam")
+			?.Select(b => b.Data.ReadAsString())
+			?.ToList();
+
+		if (chapterNames is null) return null;
+
+		List<SttsBox.SampleEntry> sampleTimes = textTrak!.Mdia.Minf.Stbl.Stts.Samples;
+
+		if (sampleTimes.Count != chapterNames.Count) return null;
+
+		var cEntryList = new ChunkEntryList(textTrak).OrderBy(s => s.ChunkOffset).ToList();
+
+		if (cEntryList.Count != chapterNames.Count) return null;
+
+		ChapterInfo chapterInfo = new();
+
+		int subtractNext = 0;
+
+		for (int i = 0; i < chapterNames.Count; i++)
+		{
+			var sif = (int)sampleTimes[i].FrameDelta;
+
+			TimeSpan duration = TimeSpan.FromSeconds(Math.Max(0d, sif + subtractNext) / TimeScale);
+			chapterInfo.AddChapter(chapterNames[(int)cEntryList[i].ChunkIndex], duration);
+			subtractNext = sif < 0 ? sif : 0;
+		}
+
+		Chapters ??= chapterInfo;
+
+		return chapterInfo;
+	}
+
 	~Mpeg4File()
 	{
 		Dispose(disposing: false);

src/Mpeg4Lib/ChapterInfo.cs

@@ -7,7 +7,7 @@ namespace AAXClean.Test
 	[TestClass]
 	public class AC_AaxTest : AaxTestBase
 	{
-		private ChapterInfo _chapters;
+		private Mpeg4Lib.ChapterInfo _chapters;
 		private TestBookTags _tags;
 
 		public override string AaxFile => TestFiles.AC_BookPath;
@@ -19,13 +19,13 @@ public class AC_AaxTest : AaxTestBase
 		public override long RenderSize => 5872527L;
 		public override TimeSpan Duration => TimeSpan.FromTicks(618328816326);
 
-		public override ChapterInfo Chapters
+		public override Mpeg4Lib.ChapterInfo Chapters
 		{
 			get
 			{
 				if (_chapters is null)
 				{
-					_chapters = new ChapterInfo
+					_chapters = new Mpeg4Lib.ChapterInfo
 					{
 						{ "PROLOGUE", TimeSpan.FromTicks(7327059863) },
 						{ "PART ONE: ARRIVAL - (Needlecast Download)", TimeSpan.FromTicks(32380045) },