All modern browsers will play video (Theora andWebM) and audio (Vorbis andMP3) files from Wikipedia, no modifications needed.
On olderiOS,iPadOS, andmacOS devices, software decoding will be used. This might be a bit slow compared to what you are used to on such devices.Internet Explorer is NOT supported.
You can try your player using theWikimedia Commons Sound andVideo files.
To learn how to create video or audio files for Wikipedia and its sister projects, checkWikipedia:Creation and usage of media files.