diff --git a/bin/oxframe b/bin/oxframe
index 9da3409..25812d0 100755
--- a/bin/oxframe
+++ b/bin/oxframe
@@ -26,7 +26,7 @@ if __name__ == '__main__':
     parser = OptionParser()
     parser.add_option('-x', '--width', dest='width', help='scale image to given width')
     parser.add_option('-y', '--height', dest='height', help='scale image to given height')
-    parser.add_option('-p', '--pos', dest='pos', help='frame position in milliseconds')
+    parser.add_option('-p', '--pos', dest='pos', help='frame position in seconds, float')
     parser.add_option('-i', '--input', dest='input', help='video input')
     parser.add_option('-o', '--output', dest='output', help='path to save frame to, jpg, png supported')
     (opts, args) = parser.parse_args()
diff --git a/oxgst/video.py b/oxgst/video.py
index be92794..0c70f57 100644
--- a/oxgst/video.py
+++ b/oxgst/video.py
@@ -25,7 +25,7 @@ class Video(gst.Pipeline):
         # queue callbacks
         self.callback = {}
         # extracted frames
-        self.frames = {}
+        self._frames = {}
 
         # true only if we are prerolled
         self._ready = False
@@ -119,13 +119,13 @@ class Video(gst.Pipeline):
 
     def frame(self, timestamp):
         mainloop = gobject.MainLoop()
-        self.frames[timestamp] = None
+        self._frames[timestamp] = None
         def callback(frame, timestamp):
-            self.frames[timestamp] = frame
+            self._frames[timestamp] = frame
             mainloop.quit()
         if self.getFrame(timestamp, callback):
             mainloop.run()
-        frame = self.frames[timestamp]
-        del self.frames[timestamp]
+        frame = self._frames[timestamp]
+        del self._frames[timestamp]
         return frame