The documentation, from what I can see, tells me nothing about how to fix QTBUG-96598. I'm trying to play an .mkv file on macOS.
If i go to https://doc-snapshots.qt.io/qt6-6.2/qtmultimedia-index.html, the next logical place is the video overview: https://doc-snapshots.qt.io/qt6-6.2/videooverview.html. That doesn't mention anything about e.g. codecs, so I went to https://doc-snapshots.qt.io/qt6-6.2/qml-qtmultimedia-videooutput.html and https://doc-snapshots.qt.io/qt6-6.2/qml-qtmultimedia-mediaplayer.html, but they didn't either.
If I search for e.g. "qt multimedia play mkv", I get this bug report, which seems to suggest that you need certain codecs to play certain video formats. If that is the case, the documentation should mention it so that I know how to fix the issue.