-        uploader_str = self._search_regex(r'<span>Uploaded by</span>(.*?)<span>', webpage, 'uploader', fatal=False)
-        mobj = re.search(r'<a href="/sites/(?P<id>[^"]+)"><strong>(?P<name>[^<]+)</strong></a>', uploader_str)
-        (uploader, uploader_id) = (mobj.group('name'), mobj.group('id')) if mobj else (clean_html(uploader_str), None)
+        media_id = self._search_regex(
+            r'<button[^>]+data-id=(["\'])(?P<id>\d+)\1[^>]+data-quality=', webpage,
+            'media id', default=None, group='id')
+        sources = [
+            quality
+            for _, quality in re.findall(r'<button[^>]+data-quality=(["\'])(.+?)\1', webpage)]
+        if not (media_id and sources):
+            player_js = self._download_webpage(
+                self._search_regex(
+                    r'<script[^>]id=(["\'])playerembed\1[^>]+src=(["\'])(?P<url>.+?)\2',
+                    webpage, 'player JS', group='url'),
+                video_id, 'Downloading player JS')
+            params_js = self._search_regex(
+                r'\$\.ajax\(url,\ opts\);\s*\}\s*\}\)\(([0-9,\[\] ]+)\)',
+                player_js, 'initialization parameters')
+            params = self._parse_json('[%s]' % params_js, video_id)
+            media_id = params[0]
+            sources = ['%s' % p for p in params[2]]