Began parsing Threemedia OTT fragments.

skyscraper8/ThreemediaOtt/ThreemediaBaseStream.cs

@@ -0,0 +1,90 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace skyscraper8.ThreemediaOtt
+{
+	internal abstract class ThreemediaBaseStream : Stream
+	{
+		public override void Flush()
+		{
+			throw new NotSupportedException();
+		}
+
+		public override long Position
+		{
+			get
+			{
+				return _internalPosition;
+			}
+			set
+			{
+				if (value > calculatedLength)
+				{
+					throw new ArgumentOutOfRangeException(nameof(value), value, String.Format("This stream is capped at {0}", calculatedLength));
+				}
+
+				Seek(value, SeekOrigin.Begin);
+			}
+		}
+
+		public override long Seek(long offset, SeekOrigin origin)
+		{
+			long newPosition;
+			switch (origin)
+			{
+				case SeekOrigin.Begin:
+					newPosition = offset;
+					break;
+				case SeekOrigin.Current:
+					newPosition = Position + offset;
+					break;
+				case SeekOrigin.End:
+					newPosition = Length + offset;
+					break;
+				default:
+					throw new NotImplementedException(String.Format("Unknown seek operation: {0}", origin));
+			}
+
+			if (newPosition < 0 || newPosition > calculatedLength)
+			{
+				throw new IOException("An attempt was made to move the file pointer before the beginning or past the end of the stream.");
+			}
+
+			SeekHook();
+
+			return newPosition;
+		}
+
+		protected abstract void SeekHook();
+
+		private bool lengthSet;
+		private long calculatedLength;
+		public override void SetLength(long value)
+		{
+			if (lengthSet)
+			{
+				throw new NotSupportedException();
+			}
+			else
+			{
+				calculatedLength = value;
+				lengthSet = true;
+			}
+		}
+
+		public override void Write(byte[] buffer, int offset, int count)
+		{
+			throw new NotSupportedException();
+		}
+
+		public override bool CanRead => true;
+		public override bool CanSeek => true;
+		public override bool CanWrite => false;
+		public override long Length => calculatedLength;
+
+		protected long _internalPosition;
+	}
+}

skyscraper8/ThreemediaOtt/ThreemediaContentFragment.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using skyscraper5.Skyscraper.IO;
 using skyscraper8.Ietf.FLUTE;
 
 namespace skyscraper8.ThreemediaOtt
@@ -52,5 +53,41 @@ namespace skyscraper8.ThreemediaOtt
 
 			return true;
 		}
+
+		public ThreemediaContentFragmentStream CreateStream()
+		{
+			byte[] lastBlock = blocks[blocks.Length - 1];
+
+			MemoryStream lastBlockStream = new MemoryStream(lastBlock, false);
+			lastBlockStream.Position = lastBlockStream.Length - 8;
+			int footerLength = (int)lastBlockStream.ReadUInt32BE();
+			int footerOffset = (int)(lastBlockStream.Length - 8 - footerLength);
+
+			Dictionary<string, string> footer = ExtractFooter(lastBlock, footerLength, footerOffset);
+
+			int[] blockSizes = Array.ConvertAll(blocks, (x) => x.Length);
+			blockSizes[blocks.Length - 1] = footerOffset;
+
+			ThreemediaContentFragmentStream result = new ThreemediaContentFragmentStream(blocks, blockSizes, footer);
+
+			throw new NotImplementedException();
+		}
+
+		private Dictionary<string, string> ExtractFooter(byte[] lastBlock, int footerLength, int footerOffset)
+		{
+			MemoryStream ms = new MemoryStream(lastBlock, footerOffset, footerLength, false);
+			StreamReader sr = new StreamReader(ms, Encoding.ASCII);
+			Dictionary<string, string> result = new Dictionary<string, string>();
+			while (!sr.EndOfStream)
+			{
+				string? line = sr.ReadLine();
+				int seperator = line.IndexOf(':');
+				string key = line.Substring(0, seperator);
+				string value = line.Substring(seperator + 1);
+				result.Add(key, value);
+			}
+
+			return result;
+		}
 	}
 }

skyscraper8/ThreemediaOtt/ThreemediaContentFragmentStream.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace skyscraper8.ThreemediaOtt
+{
+	internal class ThreemediaContentFragmentStream : ThreemediaBaseStream
+	{
+		private readonly byte[][] _blocks;
+		private readonly int[] _blockSizes;
+		
+		private int _currentBlockIndex;
+		private int _currentBlockPosition;
+
+		public ThreemediaContentFragmentStream(byte[][] blocks, int[] blockSizes, Dictionary<string, string> footer)
+		{
+			_blocks = blocks ?? throw new ArgumentNullException(nameof(blocks));
+			_blockSizes = blockSizes ?? throw new ArgumentNullException(nameof(blockSizes));
+
+			if (_blocks.Length != _blockSizes.Length)
+			{
+				throw new ArgumentException("Blocks and blockSizes arrays must have the same length.");
+			}
+
+			// Calculate total stream length based on the valid payloads
+			SetLength(_blockSizes.Sum(x => (long)x));
+		}
+
+		public override int Read(byte[] buffer, int offset, int count)
+		{
+			throw new NotImplementedException();
+		}
+
+		protected override void SeekHook()
+		{
+			long remainingOffset = _internalPosition;
+			_currentBlockIndex = 0;
+			_currentBlockPosition = 0;
+
+			while (_currentBlockIndex < _blocks.Length && remainingOffset > 0)
+			{
+				int blockSize = _blockSizes[_currentBlockIndex];
+				if (remainingOffset >= blockSize)
+				{
+					remainingOffset -= blockSize;
+					_currentBlockIndex++;
+				}
+				else
+				{
+					_currentBlockPosition = (int)remainingOffset;
+					remainingOffset = 0;
+				}
+			}
+		}
+	}
+}

skyscraper8/ThreemediaOtt/ThreemediaOttHandler.cs

@@ -107,7 +107,12 @@ namespace skyscraper8.ThreemediaOtt
 				return;
 			}
 
-			throw new NotImplementedException();
+			ThreemediaSessionStream stream = selectedSession.CreateStream();
+
+			FileStream fs = File.OpenWrite("test.bin");
+			stream.CopyTo(fs);
+			fs.Flush(true);
+			fs.Close();
 		}
 
 		public bool StopProcessingAfterThis()

skyscraper8/ThreemediaOtt/ThreemediaSession.cs

@@ -55,5 +55,12 @@ namespace skyscraper8.ThreemediaOtt
 
 			fragments = null;
 		}
+
+		public ThreemediaSessionStream CreateStream()
+		{
+			ThreemediaContentFragmentStream[] fragmentStreams = Array.ConvertAll(fragments, (x) => x.CreateStream());
+			ThreemediaSessionStream stream = new ThreemediaSessionStream(fragmentStreams);
+			return stream;
+		}
 	}
 }

skyscraper8/ThreemediaOtt/ThreemediaSessionStream.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace skyscraper8.ThreemediaOtt
+{
+	internal class ThreemediaSessionStream : ThreemediaBaseStream
+	{
+		public ThreemediaSessionStream(ThreemediaContentFragmentStream[] fragmentStreams)
+		{
+			throw new NotImplementedException();
+		}
+
+		public override int Read(byte[] buffer, int offset, int count)
+		{
+			throw new NotImplementedException();
+		}
+
+		protected override void SeekHook()
+		{
+			throw new NotImplementedException();
+		}
+	}
+}