Plugin cleanup and tweaks

plugins/youtube_download/yt_dlp/extractor/digitalconcerthall.py

@@ -1,6 +1,3 @@
-# coding: utf-8
-from __future__ import unicode_literals
-
 from .common import InfoExtractor
 
 from ..utils import (
@@ -45,10 +42,7 @@ class DigitalConcertHallIE(InfoExtractor):
         'playlist_count': 3,
     }]
 
-    def _login(self):
-        username, password = self._get_login_info()
-        if not username:
-            self.raise_login_required()
+    def _perform_login(self, username, password):
         token_response = self._download_json(
             self._OAUTH_URL,
             None, 'Obtaining token', errnote='Unable to obtain token', data=urlencode_postdata({
@@ -78,7 +72,8 @@ class DigitalConcertHallIE(InfoExtractor):
             self.raise_login_required(msg='Login info incorrect')
 
     def _real_initialize(self):
-        self._login()
+        if not self._ACCESS_TOKEN:
+            self.raise_login_required(method='password')
 
     def _entries(self, items, language, **kwargs):
         for item in items:
@@ -91,9 +86,8 @@ class DigitalConcertHallIE(InfoExtractor):
                 })
 
             m3u8_url = traverse_obj(
-                stream_info, ('channel', lambda x: x.startswith('vod_mixed'), 'stream', 0, 'url'), get_all=False)
+                stream_info, ('channel', lambda k, _: k.startswith('vod_mixed'), 'stream', 0, 'url'), get_all=False)
             formats = self._extract_m3u8_formats(m3u8_url, video_id, 'mp4', 'm3u8_native', fatal=False)
-            self._sort_formats(formats)
 
             yield {
                 'id': video_id,