diff --git a/enzyme/mkv.py b/enzyme/mkv.py
index f90c043..9dbce9b 100644
--- a/enzyme/mkv.py
+++ b/enzyme/mkv.py
@@ -157,7 +157,7 @@ def fromelement(cls, element):
         type = element.get('TrackType')  # @ReservedAssignment
         number = element.get('TrackNumber', 0)
         name = element.get('Name')
-        language = element.get('Language', 'eng')
+        language = element.get('Language')
         enabled = bool(element.get('FlagEnabled', 1))
         default = bool(element.get('FlagDefault', 1))
         forced = bool(element.get('FlagForced', 0))
@@ -201,7 +201,7 @@ def fromelement(cls, element):
         videotrack.width = element['Video'].get('PixelWidth', 0)
         videotrack.height = element['Video'].get('PixelHeight', 0)
         videotrack.interlaced = bool(element['Video'].get('FlagInterlaced', False))
-        videotrack.stereo_mode = element['Video'].get('StereoMode', 0)
+        videotrack.stereo_mode = element['Video'].get('StereoMode')
         videotrack.crop = {}
         if 'PixelCropTop' in element['Video']:
             videotrack.crop['top'] = element['Video']['PixelCropTop']
@@ -211,10 +211,10 @@ def fromelement(cls, element):
             videotrack.crop['left'] = element['Video']['PixelCropLeft']
         if 'PixelCropRight' in element['Video']:
             videotrack.crop['right'] = element['Video']['PixelCropRight']
-        videotrack.display_unit = element['Video'].get('DisplayUnit')
         videotrack.display_width = element['Video'].get('DisplayWidth')
         videotrack.display_height = element['Video'].get('DisplayHeight')
-        videotrack.aspect_ratio_type = element['Video'].get('AspectRatioType', 0)
+        videotrack.display_unit = element['Video'].get('DisplayUnit')
+        videotrack.aspect_ratio_type = element['Video'].get('AspectRatioType')
         return videotrack
 
     def __repr__(self):
@@ -245,7 +245,7 @@ def fromelement(cls, element):
         audiotrack = super(AudioTrack, cls).fromelement(element)
         audiotrack.sampling_frequency = element['Audio'].get('SamplingFrequency', 8000.0)
         audiotrack.channels = element['Audio'].get('Channels', 1)
-        audiotrack.output_sampling_frequency = element['Audio'].get('OutputSamplingFrequency', audiotrack.sampling_frequency)
+        audiotrack.output_sampling_frequency = element['Audio'].get('OutputSamplingFrequency')
         audiotrack.bit_depth = element['Audio'].get('BitDepth')
         return audiotrack
 
diff --git a/enzyme/tests/test_mkv.py b/enzyme/tests/test_mkv.py
index e97d760..2403661 100644
--- a/enzyme/tests/test_mkv.py
+++ b/enzyme/tests/test_mkv.py
@@ -44,12 +44,12 @@ def test_test1(self):
         self.assertTrue(mkv.video_tracks[0].width == 854)
         self.assertTrue(mkv.video_tracks[0].height == 480)
         self.assertTrue(mkv.video_tracks[0].interlaced == False)
-        self.assertTrue(mkv.video_tracks[0].stereo_mode == 0)
+        self.assertTrue(mkv.video_tracks[0].stereo_mode is None)
         self.assertTrue(mkv.video_tracks[0].crop == {})
         self.assertTrue(mkv.video_tracks[0].display_width is None)
         self.assertTrue(mkv.video_tracks[0].display_height is None)
         self.assertTrue(mkv.video_tracks[0].display_unit is None)
-        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type == 0)
+        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type is None)
         # audio track
         self.assertTrue(len(mkv.audio_tracks) == 1)
         self.assertTrue(mkv.audio_tracks[0].type == AUDIO_TRACK)
@@ -64,7 +64,7 @@ def test_test1(self):
         self.assertTrue(mkv.audio_tracks[0].codec_name is None)
         self.assertTrue(mkv.audio_tracks[0].sampling_frequency == 48000.0)
         self.assertTrue(mkv.audio_tracks[0].channels == 2)
-        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency == 48000.0)
+        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency is None)
         self.assertTrue(mkv.audio_tracks[0].bit_depth is None)
         # subtitle track
         self.assertTrue(len(mkv.subtitle_tracks) == 0)
@@ -113,12 +113,12 @@ def test_test2(self):
         self.assertTrue(mkv.video_tracks[0].width == 1024)
         self.assertTrue(mkv.video_tracks[0].height == 576)
         self.assertTrue(mkv.video_tracks[0].interlaced == False)
-        self.assertTrue(mkv.video_tracks[0].stereo_mode == 0)
+        self.assertTrue(mkv.video_tracks[0].stereo_mode is None)
         self.assertTrue(mkv.video_tracks[0].crop == {})
         self.assertTrue(mkv.video_tracks[0].display_width == 1354)
         self.assertTrue(mkv.video_tracks[0].display_height is None)
         self.assertTrue(mkv.video_tracks[0].display_unit is None)
-        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type == 0)
+        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type is None)
         # audio track
         self.assertTrue(len(mkv.audio_tracks) == 1)
         self.assertTrue(mkv.audio_tracks[0].type == AUDIO_TRACK)
@@ -133,7 +133,7 @@ def test_test2(self):
         self.assertTrue(mkv.audio_tracks[0].codec_name is None)
         self.assertTrue(mkv.audio_tracks[0].sampling_frequency == 48000.0)
         self.assertTrue(mkv.audio_tracks[0].channels == 2)
-        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency == 48000.0)
+        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency is None)
         self.assertTrue(mkv.audio_tracks[0].bit_depth is None)
         # subtitle track
         self.assertTrue(len(mkv.subtitle_tracks) == 0)
@@ -182,18 +182,18 @@ def test_test3(self):
         self.assertTrue(mkv.video_tracks[0].width == 1024)
         self.assertTrue(mkv.video_tracks[0].height == 576)
         self.assertTrue(mkv.video_tracks[0].interlaced == False)
-        self.assertTrue(mkv.video_tracks[0].stereo_mode == 0)
+        self.assertTrue(mkv.video_tracks[0].stereo_mode is None)
         self.assertTrue(mkv.video_tracks[0].crop == {})
         self.assertTrue(mkv.video_tracks[0].display_width is None)
         self.assertTrue(mkv.video_tracks[0].display_height is None)
         self.assertTrue(mkv.video_tracks[0].display_unit is None)
-        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type == 0)
+        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type is None)
         # audio track
         self.assertTrue(len(mkv.audio_tracks) == 1)
         self.assertTrue(mkv.audio_tracks[0].type == AUDIO_TRACK)
         self.assertTrue(mkv.audio_tracks[0].number == 2)
         self.assertTrue(mkv.audio_tracks[0].name is None)
-        self.assertTrue(mkv.audio_tracks[0].language == 'eng')
+        self.assertTrue(mkv.audio_tracks[0].language is None)
         self.assertTrue(mkv.audio_tracks[0].enabled == True)
         self.assertTrue(mkv.audio_tracks[0].default == True)
         self.assertTrue(mkv.audio_tracks[0].forced == False)
@@ -202,7 +202,7 @@ def test_test3(self):
         self.assertTrue(mkv.audio_tracks[0].codec_name is None)
         self.assertTrue(mkv.audio_tracks[0].sampling_frequency == 48000.0)
         self.assertTrue(mkv.audio_tracks[0].channels == 2)
-        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency == 48000.0)
+        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency is None)
         self.assertTrue(mkv.audio_tracks[0].bit_depth is None)
         # subtitle track
         self.assertTrue(len(mkv.subtitle_tracks) == 0)
@@ -251,12 +251,12 @@ def test_test5(self):
         self.assertTrue(mkv.video_tracks[0].width == 1024)
         self.assertTrue(mkv.video_tracks[0].height == 576)
         self.assertTrue(mkv.video_tracks[0].interlaced == False)
-        self.assertTrue(mkv.video_tracks[0].stereo_mode == 0)
+        self.assertTrue(mkv.video_tracks[0].stereo_mode is None)
         self.assertTrue(mkv.video_tracks[0].crop == {})
         self.assertTrue(mkv.video_tracks[0].display_width == 1024)
         self.assertTrue(mkv.video_tracks[0].display_height == 576)
         self.assertTrue(mkv.video_tracks[0].display_unit is None)
-        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type == 0)
+        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type is None)
         # audio tracks
         self.assertTrue(len(mkv.audio_tracks) == 2)
         self.assertTrue(mkv.audio_tracks[0].type == AUDIO_TRACK)
@@ -271,12 +271,12 @@ def test_test5(self):
         self.assertTrue(mkv.audio_tracks[0].codec_name is None)
         self.assertTrue(mkv.audio_tracks[0].sampling_frequency == 48000.0)
         self.assertTrue(mkv.audio_tracks[0].channels == 2)
-        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency == 48000.0)
+        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency is None)
         self.assertTrue(mkv.audio_tracks[0].bit_depth is None)
         self.assertTrue(mkv.audio_tracks[1].type == AUDIO_TRACK)
         self.assertTrue(mkv.audio_tracks[1].number == 10)
         self.assertTrue(mkv.audio_tracks[1].name == 'Commentary')
-        self.assertTrue(mkv.audio_tracks[1].language == 'eng')
+        self.assertTrue(mkv.audio_tracks[1].language is None)
         self.assertTrue(mkv.audio_tracks[1].enabled == True)
         self.assertTrue(mkv.audio_tracks[1].default == False)
         self.assertTrue(mkv.audio_tracks[1].forced == False)
@@ -292,7 +292,7 @@ def test_test5(self):
         self.assertTrue(mkv.subtitle_tracks[0].type == SUBTITLE_TRACK)
         self.assertTrue(mkv.subtitle_tracks[0].number == 3)
         self.assertTrue(mkv.subtitle_tracks[0].name is None)
-        self.assertTrue(mkv.subtitle_tracks[0].language == 'eng')
+        self.assertTrue(mkv.subtitle_tracks[0].language is None)
         self.assertTrue(mkv.subtitle_tracks[0].enabled == True)
         self.assertTrue(mkv.subtitle_tracks[0].default == True)
         self.assertTrue(mkv.subtitle_tracks[0].forced == False)
@@ -414,12 +414,12 @@ def test_test6(self):
         self.assertTrue(mkv.video_tracks[0].width == 854)
         self.assertTrue(mkv.video_tracks[0].height == 480)
         self.assertTrue(mkv.video_tracks[0].interlaced == False)
-        self.assertTrue(mkv.video_tracks[0].stereo_mode == 0)
+        self.assertTrue(mkv.video_tracks[0].stereo_mode is None)
         self.assertTrue(mkv.video_tracks[0].crop == {})
         self.assertTrue(mkv.video_tracks[0].display_width is None)
         self.assertTrue(mkv.video_tracks[0].display_height is None)
         self.assertTrue(mkv.video_tracks[0].display_unit is None)
-        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type == 0)
+        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type is None)
         # audio track
         self.assertTrue(len(mkv.audio_tracks) == 1)
         self.assertTrue(mkv.audio_tracks[0].type == AUDIO_TRACK)
@@ -434,7 +434,7 @@ def test_test6(self):
         self.assertTrue(mkv.audio_tracks[0].codec_name is None)
         self.assertTrue(mkv.audio_tracks[0].sampling_frequency == 48000.0)
         self.assertTrue(mkv.audio_tracks[0].channels == 2)
-        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency == 48000.0)
+        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency is None)
         self.assertTrue(mkv.audio_tracks[0].bit_depth is None)
         # subtitle track
         self.assertTrue(len(mkv.subtitle_tracks) == 0)
@@ -483,12 +483,12 @@ def test_test7(self):
         self.assertTrue(mkv.video_tracks[0].width == 1024)
         self.assertTrue(mkv.video_tracks[0].height == 576)
         self.assertTrue(mkv.video_tracks[0].interlaced == False)
-        self.assertTrue(mkv.video_tracks[0].stereo_mode == 0)
+        self.assertTrue(mkv.video_tracks[0].stereo_mode is None)
         self.assertTrue(mkv.video_tracks[0].crop == {})
         self.assertTrue(mkv.video_tracks[0].display_width is None)
         self.assertTrue(mkv.video_tracks[0].display_height is None)
         self.assertTrue(mkv.video_tracks[0].display_unit is None)
-        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type == 0)
+        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type is None)
         # audio track
         self.assertTrue(len(mkv.audio_tracks) == 1)
         self.assertTrue(mkv.audio_tracks[0].type == AUDIO_TRACK)
@@ -503,7 +503,7 @@ def test_test7(self):
         self.assertTrue(mkv.audio_tracks[0].codec_name is None)
         self.assertTrue(mkv.audio_tracks[0].sampling_frequency == 48000.0)
         self.assertTrue(mkv.audio_tracks[0].channels == 2)
-        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency == 48000.0)
+        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency is None)
         self.assertTrue(mkv.audio_tracks[0].bit_depth is None)
         # subtitle track
         self.assertTrue(len(mkv.subtitle_tracks) == 0)
@@ -552,12 +552,12 @@ def test_test8(self):
         self.assertTrue(mkv.video_tracks[0].width == 1024)
         self.assertTrue(mkv.video_tracks[0].height == 576)
         self.assertTrue(mkv.video_tracks[0].interlaced == False)
-        self.assertTrue(mkv.video_tracks[0].stereo_mode == 0)
+        self.assertTrue(mkv.video_tracks[0].stereo_mode is None)
         self.assertTrue(mkv.video_tracks[0].crop == {})
         self.assertTrue(mkv.video_tracks[0].display_width is None)
         self.assertTrue(mkv.video_tracks[0].display_height is None)
         self.assertTrue(mkv.video_tracks[0].display_unit is None)
-        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type == 0)
+        self.assertTrue(mkv.video_tracks[0].aspect_ratio_type is None)
         # audio track
         self.assertTrue(len(mkv.audio_tracks) == 1)
         self.assertTrue(mkv.audio_tracks[0].type == AUDIO_TRACK)
@@ -572,7 +572,7 @@ def test_test8(self):
         self.assertTrue(mkv.audio_tracks[0].codec_name is None)
         self.assertTrue(mkv.audio_tracks[0].sampling_frequency == 48000.0)
         self.assertTrue(mkv.audio_tracks[0].channels == 2)
-        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency == 48000.0)
+        self.assertTrue(mkv.audio_tracks[0].output_sampling_frequency is None)
         self.assertTrue(mkv.audio_tracks[0].bit_depth is None)
         # subtitle track
         self.assertTrue(len(mkv.subtitle_tracks) == 0)