feat(id3): support apple MVNM/MVIN frame

src/TaglibSharp.Tests/TaggingFormats/Id3V2Test.cs

@@ -1499,6 +1499,54 @@ public void TestUserTextInformationFrame ()
 				});
 		}
 
+		[Test]
+		public void TestMovementNameFrame ()
+		{
+			ByteVector id = "MVNM";
+			var frame = new TextInformationFrame (id) {
+				Text = val_mult
+			};
+
+			FrameTest (frame, 2,
+				delegate (Frame f, StringType e) {
+					(f as TextInformationFrame).TextEncoding = e;
+				},
+				(d, v) => new TextInformationFrame (d, v),
+
+				delegate (Frame f, string m) {
+					var g = (f as TextInformationFrame);
+					Assert.AreEqual (id, g.FrameId, m);
+					Assert.AreEqual (val_mult.Length, g.Text.Length, m);
+					for (int i = 0; i < val_mult.Length; i++) {
+						Assert.AreEqual (val_mult[i], g.Text[i], m);
+					}
+				});
+		}
+
+		[Test]
+		public void TestMovementNumberFrame ()
+		{
+			ByteVector id = "MVIN";
+			var frame = new TextInformationFrame (id) {
+				Text = val_mult
+			};
+
+			FrameTest (frame, 2,
+				delegate (Frame f, StringType e) {
+					(f as TextInformationFrame).TextEncoding = e;
+				},
+				(d, v) => new TextInformationFrame (d, v),
+
+				delegate (Frame f, string m) {
+					var g = (f as TextInformationFrame);
+					Assert.AreEqual (id, g.FrameId, m);
+					Assert.AreEqual (val_mult.Length, g.Text.Length, m);
+					for (int i = 0; i < val_mult.Length; i++) {
+						Assert.AreEqual (val_mult[i], g.Text[i], m);
+					}
+				});
+		}
+
 		[Test]
 		public void TestUniqueFileIdentifierFrame ()
 		{

src/TaglibSharp/Id3v2/FrameFactory.cs

@@ -216,7 +216,10 @@ public static Frame CreateFrame (ByteVector data, File file, ref int offset, byt
 			if (header.FrameId == FrameType.TXXX)
 				return new UserTextInformationFrame (data, position, header, version);
 
-			if (header.FrameId[0] == (byte)'T')
+			// Apple proprietary MVNM (Movement Name), MVIN (Movement Number) are in fact text frames.
+			if (header.FrameId[0] == (byte)'T' ||
+				header.FrameId == "MVNM" ||
+				header.FrameId == "MVIN")
 				return new TextInformationFrame (data, position, header, version);
 
 			// Involved People List (frames 4.4 in 2.3. in 2.4 this is a TIPL frame)

src/TaglibSharp/Id3v2/FrameHeader.cs

@@ -381,7 +381,7 @@ static ReadOnlyByteVector ConvertId (ByteVector id, byte version, bool toVersion
 		}
 
 		static readonly ReadOnlyByteVector[,] version2_frames =
-			new ReadOnlyByteVector[59, 2] {
+			new ReadOnlyByteVector[61, 2] {
 				{ "BUF", "RBUF" },
 				{ "CNT", "PCNT" },
 				{ "COM", "COMM" },
@@ -440,7 +440,9 @@ static ReadOnlyByteVector ConvertId (ByteVector id, byte version, bool toVersion
 				{ "WCP", "WCOP" },
 				{ "WPB", "WPUB" },
 				{ "WXX", "WXXX" },
-				{ "XRV", "RVA2" }
+				{ "XRV", "RVA2" },
+				{ "MVN", "MVNM" },
+				{ "MVI", "MVIN" }
 			};
 
 		static readonly ReadOnlyByteVector[,] version3_frames =

src/TaglibSharp/Id3v2/FrameTypes.cs

@@ -101,5 +101,7 @@ static class FrameType
 		public static readonly ReadOnlyByteVector WPUB = "WPUB";
 		public static readonly ReadOnlyByteVector WXXX = "WXXX";
 		public static readonly ReadOnlyByteVector ETCO = "ETCO";
+		public static readonly ReadOnlyByteVector MVNM = "MVNM"; // Movement Name
+		public static readonly ReadOnlyByteVector MVIN = "MVIN"; // Movement Number/Count
 	}
 }

src/TaglibSharp/Id3v2/Frames/TextIdentificationFrame.cs

@@ -875,7 +875,9 @@ protected void ParseRawData ()
 					FrameId == FrameType.TPE1 ||
 					FrameId == FrameType.TPE2 ||
 					FrameId == FrameType.TPE3 ||
-					FrameId == FrameType.TPE4) {
+					FrameId == FrameType.TPE4 ||
+					FrameId == FrameType.MVNM ||
+					FrameId == FrameType.MVIN) {
 					field_list.AddRange (value.Split ('/'));
 				} else if (FrameId == FrameType.TCON) {
 					while (value.Length > 1 && value[0] == '(') {