taglib-sharp initial import (r553)

taglib-sharp/examples/StripImageData.cs

@@ -0,0 +1,117 @@
+
+using System;
+using TagLib;
+
+public class StripImageData
+{
+	private static byte[] image_data = new byte[] {
+		0xFF, 0xDA, 0x00, 0x0C, 0x03, 0x01, 0x00,
+		0x02, 0x11, 0x03, 0x11, 0x00, 0x3F, 0x00,
+		0x8C, 0x80, 0x07, 0xFF, 0xD9
+	};
+
+	public static void Main (string [] args)
+	{
+		if (args.Length != 1) {
+			Console.Out.WriteLine ("usage: mono StripImageData.exe [jpegfile]");
+			return;
+		}
+
+		ImageFile file = new ImageFile (args [0]);
+
+		file.Mode = File.AccessMode.Write;
+
+		long greatest_segment_position = 0;
+		long greatest_segment_length = 0;
+
+		// collect data segments
+		while (true) {
+
+			long sos = file.Find (new byte [] {0xFF, 0xDA}, file.Tell);
+
+			if (sos == -1)
+				break;
+
+			file.Seek (sos);
+
+			long segment_length = SkipDataSegment (file);
+
+			if (segment_length > greatest_segment_length) {
+				greatest_segment_length = segment_length;
+				greatest_segment_position = sos;
+			}
+		}
+
+		if (greatest_segment_length == 0)
+		{
+			Console.Out.WriteLine ("doesn't look like an jpeg file");
+			return;
+		}
+
+		System.Console.WriteLine ("Stripping data segment at {0}", greatest_segment_position);
+
+		file.RemoveBlock (greatest_segment_position, greatest_segment_length);
+		file.Seek (greatest_segment_position);
+		file.WriteBlock (image_data);
+		file.Mode = File.AccessMode.Closed;
+	}
+
+	private static long SkipDataSegment (ImageFile file)
+	{
+		long position = file.Tell;
+
+		// skip sos maker
+		if (file.ReadBlock (2).ToUInt () != 0xFFDA)
+			throw new Exception (String.Format ("Not a data segment at position: {0}", position));
+
+		while (true) {
+			if (0xFF == (byte) file.ReadBlock (1)[0]) {
+				byte maker = (byte) file.ReadBlock (1)[0];
+
+				if (maker != 0x00 && (maker <= 0xD0 || maker >= 0xD7))
+					break;
+			}
+		}
+
+		long length = file.Tell - position - 2;
+
+		System.Console.WriteLine ("Data segment of length {0} found at {1}", length, position);
+
+		return length;
+	}
+
+	private class ImageFile : File {
+
+		// Hacky implementation to make use of some methods defined in TagLib.File
+
+		public ImageFile (string path)
+		: base (new File.LocalFileAbstraction (path)) {}
+
+		public override Tag GetTag (TagLib.TagTypes type, bool create)
+		{
+			throw new System.NotImplementedException ();
+		}
+
+		public override Properties Properties {
+			get {
+				throw new System.NotImplementedException ();
+			}
+		}
+
+		public override void RemoveTags (TagLib.TagTypes types)
+		{
+			throw new System.NotImplementedException ();
+		}
+
+		public override void Save ()
+		{
+			throw new System.NotImplementedException ();
+		}
+
+		public override Tag Tag {
+			get {
+				throw new System.NotImplementedException ();
+			}
+		}
+	}
+}