From a6673a8e82276ea529c1773ed09e5bc4a22e822a Mon Sep 17 00:00:00 2001
From: sepro <sepro@sepr0.com>
Date: Sun, 12 Oct 2025 20:30:17 +0200
Subject: [PATCH] Fix `prefer-vp9-sort` compat option (#14603)

Closes #14602
Authored by: seproDev
---
 yt_dlp/__init__.py                 | 2 +-
 yt_dlp/extractor/youtube/_video.py | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/yt_dlp/__init__.py b/yt_dlp/__init__.py
index 09c022fa0e..224679e53b 100644
--- a/yt_dlp/__init__.py
+++ b/yt_dlp/__init__.py
@@ -155,7 +155,7 @@ def set_compat_opts(opts):
     if 'format-sort' in opts.compat_opts:
         opts.format_sort.extend(FormatSorter.ytdl_default)
     elif 'prefer-vp9-sort' in opts.compat_opts:
-        opts.format_sort.extend(FormatSorter._prefer_vp9_sort)
+        FormatSorter.default = FormatSorter._prefer_vp9_sort
 
     if 'mtime-by-default' in opts.compat_opts:
         if opts.updatetime is None:
diff --git a/yt_dlp/extractor/youtube/_video.py b/yt_dlp/extractor/youtube/_video.py
index 9ef7f14dfa..864121e0a3 100644
--- a/yt_dlp/extractor/youtube/_video.py
+++ b/yt_dlp/extractor/youtube/_video.py
@@ -4110,7 +4110,9 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
                 else 'video'),
             'release_timestamp': live_start_time,
             '_format_sort_fields': (  # source_preference is lower for potentially damaged formats
-                'quality', 'res', 'fps', 'hdr:12', 'source', 'vcodec', 'channels', 'acodec', 'lang', 'proto'),
+                'quality', 'res', 'fps', 'hdr:12', 'source',
+                'vcodec:vp9.2' if 'prefer-vp9-sort' in self.get_param('compat_opts', []) else 'vcodec',
+                'channels', 'acodec', 'lang', 'proto'),
         }
 
         def get_lang_code(track):