[youtube] Move decrypt_sig out of _parse_dash_manifest

youtube_dl/extractor/youtube.py

@@ -1035,22 +1035,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
         url = 'https://www.youtube.com/annotations_invideo?features=1&legacy=1&video_id=%s' % video_id
         return self._download_webpage(url, video_id, note='Searching for annotations.', errnote='Unable to download video annotations.')
 
-    def _parse_dash_manifest(
-            self, video_id, dash_manifest_url, player_url, age_gate, fatal=True):
-        def decrypt_sig(mobj):
-            s = mobj.group(1)
-            dec_s = self._decrypt_signature(s, video_id, player_url, age_gate)
-            return '/signature/%s' % dec_s
-        dash_manifest_url = re.sub(r'/s/([a-fA-F0-9\.]+)', decrypt_sig, dash_manifest_url)
-        dash_doc = self._download_xml(
-            dash_manifest_url, video_id,
-            note='Downloading DASH manifest',
-            errnote='Could not download DASH manifest',
-            fatal=fatal)
-
-        if dash_doc is False:
-            return []
-
+    def _parse_dash_manifest(self, video_id, dash_doc, fatal=True):
         formats = []
         for a in dash_doc.findall('.//{urn:mpeg:DASH:schema:MPD:2011}AdaptationSet'):
             mime_type = a.attrib.get('mimeType')
@@ -1533,8 +1518,19 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             for dash_manifest_url in dash_mpds:
                 dash_formats = {}
                 try:
-                    for df in self._parse_dash_manifest(
-                            video_id, dash_manifest_url, player_url, age_gate, dash_mpd_fatal):
+                    def decrypt_sig(mobj):
+                        s = mobj.group(1)
+                        dec_s = self._decrypt_signature(s, video_id, player_url, age_gate)
+                        return '/signature/%s' % dec_s
+
+                    dash_manifest_url = re.sub(r'/s/([a-fA-F0-9\.]+)', decrypt_sig, dash_manifest_url)
+                    dash_doc = self._download_xml(
+                        dash_manifest_url, video_id,
+                        note='Downloading DASH manifest',
+                        errnote='Could not download DASH manifest',
+                        fatal=dash_mpd_fatal)
+
+                    for df in self._parse_dash_manifest(video_id, dash_doc, dash_mpd_fatal):
                         # Do not overwrite DASH format found in some previous DASH manifest
                         if df['format_id'] not in dash_formats:
                             dash_formats[df['format_id']] = df