change return value into pandas dataframe

itten/movie.py

@@ -156,7 +156,8 @@ class Movie(object):
             # mit übergebe ?
             data = views.MultivariateSequence(self._frames,)
             data.populate(ctrst=ctrst, method=meth, frm_stp=stp)
-            data = pd.DataFrame(data, columns=['frame', 'bin', 'pixels'])
+            data = pd.DataFrame(data, columns=['frame', 'bin', 'pixels'],
+                dtype=np.int64)
             data['time'] = data['frame'].apply(helpers.frame2time, fps=4)
 
             return data