Expand tilde in template (Fixes #1639)

youtube_dl/YoutubeDL.py

@@ -292,9 +292,11 @@ class YoutubeDL(object):
                 u'NA' if v is None else compat_str(v),
                 restricted=self.params.get('restrictfilenames'),
                 is_id=(k == u'id'))
-            template_dict = dict((k, sanitize(k, v)) for k,v in template_dict.items())
+            template_dict = dict((k, sanitize(k, v))
+                                 for k, v in template_dict.items())
 
-            filename = self.params['outtmpl'] % template_dict
+            tmpl = os.path.expanduser(self.params['outtmpl'])
+            filename = tmpl % template_dict
             return filename
         except KeyError as err:
             self.report_error(u'Erroneous output template')