diff --git a/ffmpeg/_run.py b/ffmpeg/_run.py
index f42d1d73..2cede97b 100644
--- a/ffmpeg/_run.py
+++ b/ffmpeg/_run.py
@@ -42,7 +42,9 @@ def _get_input_args(input_node):
         if fmt:
             args += ['-f', fmt]
         if video_size:
-            args += ['-video_size', '{}x{}'.format(video_size[0], video_size[1])]
+            if not isinstance(video_size, basestring):
+                video_size = '{}x{}'.format(video_size[0], video_size[1])
+            args += ['-video_size', video_size]
         args += convert_kwargs_to_cmd_line_args(kwargs)
         args += ['-i', filename]
     else:
diff --git a/ffmpeg/tests/test_ffmpeg.py b/ffmpeg/tests/test_ffmpeg.py
index 8dbc271a..cefce458 100644
--- a/ffmpeg/tests/test_ffmpeg.py
+++ b/ffmpeg/tests/test_ffmpeg.py
@@ -372,6 +372,21 @@ def test__output__video_size(video_size):
     assert args == ['-i', 'in', '-video_size', '320x240', 'out']
 
 
+@pytest.mark.parametrize(
+    'video_size,expected',
+    [
+        ((320, 240), '320x240'),
+        ([320, 240], '320x240'),
+        ('320x240', '320x240'),
+        ('1920x1080', '1920x1080'),
+        ('hd720', 'hd720'),
+    ],
+)
+def test__input__video_size(video_size, expected):
+    args = ffmpeg.input('in', video_size=video_size).output('out').get_args()
+    assert args == ['-video_size', expected, '-i', 'in', 'out']
+
+
 def test_filter_normal_arg_escape():
     """Test string escaping of normal filter args (e.g. ``font`` param of ``drawtext``
     filter).