scan mp4 in sub set

FNZCM/FNZCM.ConHost/Ver2/Program2.cs

@@ -127,7 +127,7 @@ namespace FNZCM.ConHost.Ver2
                                 var aacTrackSetPath = aacTrackSetName.ToLower();
                                 var aacTrackSet = disc.SubTracks[aacTrackSetPath] = new TrackSet(aacTrackSetName);
 
-                                foreach (var file in Directory.GetFiles(aacTrackDir, "*.m4a"))
+                                foreach (var file in FileSystem.GetFiles(aacTrackDir, SearchOption.SearchTopLevelOnly, "*.m4a", "*.mp4"))
                                 {
                                     var aacTrackName = Path.GetFileName(file);
                                     var aacTrackPath = aacTrackName.ToLower();