I would suggest to set the ffmpeg backend as default on OpenBSD as it is
on Linux/Win/Android/Mac

OK?

diff --git a/x11/qt6/qtmultimedia/Makefile b/x11/qt6/qtmultimedia/Makefile
index 9c292166897..68ba2c5678c 100644
--- a/x11/qt6/qtmultimedia/Makefile
+++ b/x11/qt6/qtmultimedia/Makefile
@@ -1,6 +1,7 @@
 QT6NAME =	QtMultimedia
 COMMENT =	Qt6 multimedia components
 PKGSPEC =	qt6-qtmultimedia-${QT6_PKGSPEC}
+REVISION =	0
 
 SHARED_LIBS +=  Qt6Multimedia             7.0 # 6.7
 SHARED_LIBS +=  Qt6MultimediaQuick        5.0 # 6.7
diff --git a/x11/qt6/qtmultimedia/patches/patch-src_multimedia_platform_qplatformmediaintegration_cpp b/x11/qt6/qtmultimedia/patches/patch-src_multimedia_platform_qplatformmediaintegration_cpp
new file mode 100644
index 00000000000..f077a02aab3
--- /dev/null
+++ b/x11/qt6/qtmultimedia/patches/patch-src_multimedia_platform_qplatformmediaintegration_cpp
@@ -0,0 +1,12 @@
+Index: src/multimedia/platform/qplatformmediaintegration.cpp
+--- src/multimedia/platform/qplatformmediaintegration.cpp.orig
++++ src/multimedia/platform/qplatformmediaintegration.cpp
+@@ -49,7 +49,7 @@ static QString defaultBackend(const QStringList &backe
+         return backend;
+ #endif
+ 
+-#if defined(Q_OS_DARWIN) || defined(Q_OS_LINUX) || defined(Q_OS_WINDOWS) || defined(Q_OS_ANDROID)
++#if defined(Q_OS_DARWIN) || defined(Q_OS_LINUX) || defined(Q_OS_WINDOWS) || defined(Q_OS_ANDROID) || defined(Q_OS_OPENBSD)
+     // Return ffmpeg backend by default.
+     // Platform backends for the OS list are optionally available but have limited support.
+     if (backends.contains(FFmpegBackend))