EDIT: Doesnt work. The few video files i did do with this method weren’t encoded to mkv specifications.
This isn’t a solution, merely a work around.
Any 720p MKV file i have always suffers from stuttering/laggy play on the wii.. and always crashes after a minute.
A quick work around is to demux it and place all streams in a new avi container.
You still have to rip apart the MKV but at least no re-encoding is required this way and the quality will be the same as the source.
Use MKVExtractGUI2(mkvextract) to extract the streams from the mkv file.
Use avc2avi to convert video stream without encoding it be avi compliant.
Use “AVIMux_GUI” to combine video stream and audio stream into avi container.
Play it.