As a web developer I prefer the last option listed: allow video to use any and all codecs installed on the users computer.
BUT, expose this information to the server, so I know which video to serve. Add an Accept-Video-Codec and an Accept-Audio-Codec header, and that is all you need to do.
For extra points send some information on screen resolution in the headers, instead of making me use javascript for it.
The reason this is good is that browers don't need to support anything. They just use the media libraries on the computer. If I want more codecs, I install them, I don't need to convice the browser to support them.
BUT, expose this information to the server, so I know which video to serve. Add an Accept-Video-Codec and an Accept-Audio-Codec header, and that is all you need to do.
For extra points send some information on screen resolution in the headers, instead of making me use javascript for it.
The reason this is good is that browers don't need to support anything. They just use the media libraries on the computer. If I want more codecs, I install them, I don't need to convice the browser to support them.