From 7a8b4a193f9dac647208eddc3808fc1985c2a6fc Mon Sep 17 00:00:00 2001
From: Marvin Kopf <marvinkopf@outlook.com>
Date: Fri, 30 May 2025 08:05:06 +0200
Subject: [PATCH] offload mpv callback registration to background thread to
 avoid UI blocking (#4038)

Instantiating `MPV(MPVBase)` triggers multiple synchronous `command()` calls to the mpv process during callback registration. These calls block the main thread and degrade startup performance. This change defers registration via `taskman.run_in_background`.
---
 CONTRIBUTORS  | 2 +-
 qt/aqt/mpv.py | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index e8814bf93..068760e6b 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -230,7 +230,7 @@ KolbyML <https://github.com/KolbyML>
 Adnane Taghi <dev@soleuniverse.me>
 Spiritual Father <https://github.com/spiritualfather>
 Emmanuel Ferdman <https://github.com/emmanuel-ferdman>
-
+Marvin Kopf <marvinkopf@outlook.com>
 ********************
 
 The text of the 3 clause BSD license follows:
diff --git a/qt/aqt/mpv.py b/qt/aqt/mpv.py
index 60ea21290..329a95538 100644
--- a/qt/aqt/mpv.py
+++ b/qt/aqt/mpv.py
@@ -41,6 +41,7 @@ import time
 from queue import Empty, Full, Queue
 from shutil import which
 
+import aqt
 from anki.utils import is_mac, is_win
 
 
@@ -444,7 +445,7 @@ class MPV(MPVBase):
 
         super().__init__(*args, **kwargs)
 
-        self._register_callbacks()
+        aqt.mw.taskman.run_in_background(self._register_callbacks, None)
 
     def _register_callbacks(self):
         self._callbacks = {}