-        stream_data = self._download_webpage(
-            streams_url, content_id, note='Downloading stream data')
-        streams = json.loads(self._search_regex(
-            r'\((.*)\);', stream_data, 'stream info'))['Streams']
+        streams = self._download_json(
+            streams_url, content_id, note='Downloading stream data',
+            transform_source=lambda s: re.sub(r'^\s*\((.*)\);\s*$', r'\1', s))['Streams']