Adjust geo restriction detection

yt_dlp/extractor/vbox7.py

@@ -68,7 +68,11 @@ class Vbox7IE(InfoExtractor):
         if src_url in (None, '', 'blank'):
             raise ExtractorError('Video is unavailable', expected=True)
 
-        fmt_base = base_url(src_url) + url_basename(src_url).rsplit('.', 1)[0].rsplit('_', 1)[0]
+        fmt_base = url_basename(src_url).rsplit('.', 1)[0].rsplit('_', 1)[0]
+        if fmt_base == 'vn':
+            self.raise_geo_restricted()
+
+        fmt_base = base_url(src_url) + fmt_base
 
         formats = self._extract_m3u8_formats(
             f'{fmt_base}.m3u8', video_id, m3u8_id='hls', fatal=False)