fix typos

youtube_dl/YoutubeDL.py

@@ -512,7 +512,7 @@ class YoutubeDL(object):
             formats_to_download = formats
         else:
             # We can accept formats requestd in the format: 34/10/5, we pick
-            # the first that is availble, starting from left
+            # the first that is available, starting from left
             req_formats = req_format.split('/')
             for rf in req_formats:
                 matches = filter(lambda f:f['format_id'] == rf ,formats)

youtube_dl/extractor/common.py

@@ -365,7 +365,7 @@ class SearchInfoExtractor(InfoExtractor):
 
     def _get_n_results(self, query, n):
         """Get a specified number of results for a query"""
-        raise NotImplementedError("This method must be implemented by sublclasses")
+        raise NotImplementedError("This method must be implemented by subclasses")
 
     @property
     def SEARCH_KEY(self):