[dvtv] Fix live streams extraction

(also fixed test broken by changed og tags on the site)

youtube_dl/extractor/dvtv.py

@@ -32,7 +32,7 @@ class DVTVIE(InfoExtractor):
     }, {
         'url': 'http://video.aktualne.cz/dvtv/dvtv-16-12-2014-utok-talibanu-boj-o-kliniku-uprchlici/r~973eb3bc854e11e498be002590604f2e/',
         'info_dict': {
-            'title': 'DVTV 16. 12. 2014: útok Talibanu, boj o kliniku, uprchlíci',
+            'title': r're:^DVTV 16\. 12\. 2014: útok Talibanu, boj o kliniku, uprchlíci',
             'id': '973eb3bc854e11e498be002590604f2e',
         },
         'playlist': [{
@@ -91,10 +91,21 @@ class DVTVIE(InfoExtractor):
     }, {
         'url': 'http://video.aktualne.cz/v-cechach-poprve-zazni-zelenkova-zrestaurovana-mse/r~45b4b00483ec11e4883b002590604f2e/',
         'only_matching': True,
+    }, {
+        'url': 'https://video.aktualne.cz/dvtv/babis-a-zeman-nesou-vinu-za-to-ze-nemame-jasno-v-tom-kdo-bud/r~026afb54fad711e79704ac1f6b220ee8/',
+        'md5': '87defe16681b1429c91f7a74809823c6',
+        'info_dict': {
+            'id': 'f5ae72f6fad611e794dbac1f6b220ee8',
+            'ext': 'mp4',
+            'title': 'Babiš a Zeman nesou vinu za to, že nemáme jasno v tom, kdo bude vládnout, říká Pekarová Adamová',
+        },
     }]
 
-    def _parse_video_metadata(self, js, video_id):
+    def _parse_video_metadata(self, js, video_id, live_js=None):
         data = self._parse_json(js, video_id, transform_source=js_to_json)
+        if live_js:
+            data.update(
+                self._parse_json(live_js, video_id, transform_source=js_to_json))
 
         title = unescapeHTML(data['title'])
 
@@ -142,13 +153,18 @@ class DVTVIE(InfoExtractor):
 
         webpage = self._download_webpage(url, video_id)
 
+        # live content
+        live_item = self._search_regex(
+            r'(?s)embedData[0-9a-f]{32}\.asset\.liveStarter\s*=\s*(\{.+?\});',
+            webpage, 'video', default=None, fatal=False)
+
         # single video
         item = self._search_regex(
             r'(?s)embedData[0-9a-f]{32}\[["\']asset["\']\]\s*=\s*(\{.+?\});',
             webpage, 'video', default=None, fatal=False)
 
         if item:
-            return self._parse_video_metadata(item, video_id)
+            return self._parse_video_metadata(item, video_id, live_item)
 
         # playlist
         items = re.findall(