fixed a typo

Author: vlsd

lib/matplotlib/animation.py

@@ -399,7 +399,7 @@ class FFMpegFileWriter(FileMovieWriter, FFMpegBase):
     def _args(self):
         # Returns the command line parameters for subprocess to use
         # ffmpeg to create a movie using a collection of temp images
-        return [self.bin_path(), '-i', self._base_temp_name()-vframes,
+        return [self.bin_path(), '-i', self._base_temp_name(),
                 '-vframes', str(self._frame_counter),
                 '-r', str(self.fps), ] + self.output_args