[StreamCZ] Fix extractor (#3789)

Closes #3579
Authored by: dirkf, adamanldo

diff --git a/yt_dlp/extractor/streamcz.py b/yt_dlp/extractor/streamcz.py
index 85fc3a3c32a902959c84c010e9ef57257f002e86..849a9882da37aba3060ff8e205aebafd87ba8b6a 100644 (file)
--- a/yt_dlp/extractor/streamcz.py
+++ b/yt_dlp/extractor/streamcz.py
@@ -52,8 +52,8 @@ class StreamCZIE(InfoExtractor):
 
     def _extract_formats(self, spl_url, video):
         for ext, pref, streams in (
-                ('ts', -1, traverse_obj(video, ('http_stream', 'qualities'))),
-                ('mp4', 1, video.get('mp4'))):
+                ('ts', -1, traverse_obj(video, ('http_stream', 'qualities')) or {}),
+                ('mp4', 1, video.get('mp4') or {})):
             for format_id, stream in streams.items():
                 if not stream.get('url'):
                     continue