[youtube] Show format ID in signature deobfuscation -v output

youtube_dl/extractor/youtube.py

@@ -806,8 +806,11 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
             url_map = {}
             for url_data_str in encoded_url_map.split(','):
                 url_data = compat_parse_qs(url_data_str)
-                if 'itag' in url_data and 'url' in url_data:
+                if 'itag' not in url_data or 'url' not in url_data:
+                    continue
+                format_id = url_data['itag'][0]
                 url = url_data['url'][0]
+
                 if 'sig' in url_data:
                     url += '&signature=' + url_data['sig'][0]
                 elif 's' in url_data:
@@ -842,15 +845,15 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                                 player_desc = u'html5 player %s' % player_version
 
                         parts_sizes = u'.'.join(compat_str(len(part)) for part in encrypted_sig.split('.'))
-                            self.to_screen(u'encrypted signature length %d (%s), itag %s, %s' %
+                        self.to_screen(u'{%s} encrypted signature length %d (%s), itag %s, %s' %
-                                (len(encrypted_sig), parts_sizes, url_data['itag'][0], player_desc))
+                            (format_id, len(encrypted_sig), parts_sizes, url_data['itag'][0], player_desc))
 
                     signature = self._decrypt_signature(
                         encrypted_sig, video_id, player_url, age_gate)
                     url += '&signature=' + signature
                 if 'ratebypass' not in url:
                     url += '&ratebypass=yes'
-                    url_map[url_data['itag'][0]] = url
+                url_map[format_id] = url
             formats = _map_to_format_list(url_map)
         elif video_info.get('hlsvp'):
             manifest_url = video_info['hlsvp'][0]