[jsinterp] Handle Date at epoch 0

See yt-dlp/yt_dlp#6400

test/test_youtube_signature.py

@@ -67,6 +67,10 @@ _SIG_TESTS = [
 ]
 
 _NSIG_TESTS = [
+    (
+        'https://www.youtube.com/s/player/7862ca1f/player_ias.vflset/en_US/base.js',
+        'X_LCxVDjAavgE5t', 'yxJ1dM6iz5ogUg',
+    ),
     (
         'https://www.youtube.com/s/player/9216d1f7/player_ias.vflset/en_US/base.js',
         'SLp9F5bwjAdhE9F-', 'gWnb9IK2DJ8Q1w',

youtube_dl/extractor/youtube.py

@@ -1694,8 +1694,9 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             if n_response is None:
                 # give up if descrambling failed
                 break
-            fmt['url'] = update_url(
-                parsed_fmt_url, query_update={'n': [n_response]})
+            for fmt_dct in traverse_obj(fmt, (None, (None, ('fragments', Ellipsis))), expected_type=dict):
+                fmt_dct['url'] = update_url(
+                    fmt_dct['url'], query_update={'n': [n_response]})
 
     # from yt-dlp, with tweaks
     def _extract_signature_timestamp(self, video_id, player_url, ytcfg=None, fatal=False):
@@ -2047,10 +2048,19 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             if no_video:
                 dct['abr'] = tbr
             if no_audio or no_video:
-                dct['downloader_options'] = {
-                    # Youtube throttles chunks >~10M
-                    'http_chunk_size': 10485760,
-                }
+                CHUNK_SIZE = 10 << 20
+                # avoid Youtube throttling
+                dct.update({
+                    'protocol': 'http_dash_segments',
+                    'fragments': [{
+                        'url': update_url_query(dct['url'], {
+                            'range': '{0}-{1}'.format(range_start, min(range_start + CHUNK_SIZE - 1, dct['filesize']))
+                        })
+                    } for range_start in range(0, dct['filesize'], CHUNK_SIZE)]
+                } if dct['filesize'] else {
+                    'downloader_options': {'http_chunk_size': CHUNK_SIZE}  # No longer useful?
+                })
+
                 if dct.get('ext'):
                     dct['container'] = dct['ext'] + '_dash'
             formats.append(dct)

youtube_dl/jsinterp.py

@@ -405,7 +405,7 @@ class JSInterpreter(object):
                 left, right = self._separate_at_paren(obj[len(klass):])
                 argvals = self.interpret_iter(left, local_vars, allow_recursion)
                 expr = konstr(*argvals)
-                if not expr:
+                if expr is None:
                     raise self.Exception('Failed to parse {klass} {left!r:.100}'.format(**locals()), expr=expr)
                 expr = self._dump(expr, local_vars) + right
                 break