[pbs] Extend _VALID_URL

youtube_dl/extractor/pbs.py

@@ -18,7 +18,7 @@ class PBSIE(InfoExtractor):
     _VALID_URL = r'''(?x)https?://
         (?:
            # Direct video URL
-           video\.pbs\.org/(?:viralplayer|video)/(?P<id>[0-9]+)/? |
+           (?:video\.pbs|watch\.knpb)\.org/(?:viralplayer|video)/(?P<id>[0-9]+)/? |
            # Article with embedded player (or direct video)
            (?:www\.)?pbs\.org/(?:[^/]+/){2,5}(?P<presumptive_id>[^/]+?)(?:\.html)?/?(?:$|[?\#]) |
            # Player
@@ -174,6 +174,10 @@ class PBSIE(InfoExtractor):
         {
             'url': 'http://player.pbs.org/widget/partnerplayer/2365297708/?start=0&end=0&chapterbar=false&endscreen=false&topbar=true',
             'only_matching': True,
+        },
+        {
+            'url': 'http://watch.knpb.org/video/2365616055/',
+            'only_matching': True,
         }
     ]
     _ERRORS = {