[youtube] Support for embedded /p players (Fixes #3821)

youtube_dl/extractor/generic.py

@@ -631,7 +631,7 @@ class GenericIE(InfoExtractor):
             )
             (["\'])
                 (?P<url>(?:https?:)?//(?:www\.)?youtube(?:-nocookie)?\.com/
-                (?:embed|v)/.+?)
+                (?:embed|v|p)/.+?)
             \1''', webpage)
         if matches:
             return _playlist_from_matches(

youtube_dl/extractor/youtube.py

@@ -1068,6 +1068,13 @@ class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
         'info_dict': {
             'title': 'JODA15',
         }
+    }, {
+        'note': 'Embedded SWF player',
+        'url': 'http://www.youtube.com/p/YN5VISEtHet5D4NEvfTd0zcgFk84NqFZ?hl=en_US&fs=1&rel=0',
+        'playlist_count': 4,
+        'info_dict': {
+            'title': 'JODA7',
+        }
     }]
 
     def _real_initialize(self):