+    def _download_subtitles_xml(self, video_id, subtitles_id, hl):
+        if self._captions_xml:
+            return
+        self._captions_xml = self._download_xml(
+            self._BASE_URL_CAPTIONS, video_id, query={
+                'id': video_id,
+                'vid': subtitles_id,
+                'hl': hl,
+                'v': video_id,
+                'type': 'list',
+                'tlangs': '1',
+                'fmts': '1',
+                'vssids': '1',
+            }, note='Downloading subtitles XML',
+            errnote='Unable to download subtitles XML', fatal=False)
+        if self._captions_xml:
+            for f in self._captions_xml.findall('format'):
+                if f.attrib.get('fmt_code') and not f.attrib.get('default'):
+                    self._caption_formats_ext.append(f.attrib['fmt_code'])
+
+    def _get_captions_by_type(self, video_id, subtitles_id, caption_type,
+                              origin_lang_code=None):
+        if not subtitles_id or not caption_type:
+            return
+        captions = {}
+        for caption_entry in self._captions_xml.findall(
+                self._CAPTIONS_ENTRY_TAG[caption_type]):
+            caption_lang_code = caption_entry.attrib.get('lang_code')
+            if not caption_lang_code:
+                continue
+            caption_format_data = []
+            for caption_format in self._caption_formats_ext:
+                query = {
+                    'vid': subtitles_id,
+                    'v': video_id,
+                    'fmt': caption_format,
+                    'lang': (caption_lang_code if origin_lang_code is None
+                             else origin_lang_code),
+                    'type': 'track',
+                    'name': '',
+                    'kind': '',
+                }
+                if origin_lang_code is not None:
+                    query.update({'tlang': caption_lang_code})
+                caption_format_data.append({
+                    'url': update_url_query(self._BASE_URL_CAPTIONS, query),
+                    'ext': caption_format,
+                })
+            captions[caption_lang_code] = caption_format_data
+        return captions
+
+    def _get_subtitles(self, video_id, subtitles_id, hl):
+        if not subtitles_id or not hl:
+            return
+        self._download_subtitles_xml(video_id, subtitles_id, hl)
+        if not self._captions_xml:
+            return
+        return self._get_captions_by_type(video_id, subtitles_id, 'subtitles')
+
+    def _get_automatic_captions(self, video_id, subtitles_id, hl):
+        if not subtitles_id or not hl:
+            return
+        self._download_subtitles_xml(video_id, subtitles_id, hl)
+        if not self._captions_xml:
+            return
+        track = self._captions_xml.find('track')
+        if track is None:
+            return
+        origin_lang_code = track.attrib.get('lang_code')
+        if not origin_lang_code:
+            return
+        return self._get_captions_by_type(
+            video_id, subtitles_id, 'automatic_captions', origin_lang_code)
+