FIX: make screenshot() before starting movie

Author: christianbrodbeck

surfer/viz.py

@@ -2250,6 +2250,9 @@ def save_movie(self, fname, time_dilation=4., tmin=None, tmax=None,
 
         logger.debug("Save movie for time points/samples\n%s\n%s"
                      % (times, time_idx))
+        # Sometimes the first screenshot is rendered with a different
+        # resolution
+        _ = self.screenshot()
         images = (self.screenshot() for _ in
                   self._iter_time(time_idx, interpolation))
         imageio.mimwrite(fname, images, **kwargs)