I was checking out this MSDN post describing multimedia redirection because it's high time we let our users view training videos through our app and not just email them a link.
Windows Media Player uses the Media Foundation infrastructure to play back content such as WMA, WMV, MP3, DivX, etc., and DirectShow for MPEG-1, MPEG-2, etc. In addition, most streaming media content is played back through the Format SDK (FSDK). Most audio and video content played back through Windows Media Player will be redirected using this scheme as long as the client has the decoder to decode the content.
The only problem is we're getting a little sick of encoding them in two formats when most folks can just use webm nowadays. So, if I have a link to a movie that Internet Explorer plays (Streaming HTML5 video using FlowPlayer) and IE chooses to play the webm file, even though I've got an MP4 handy (which I think the blog post says ought to work through multimedia redirection) will the webm be redirected or will we get more angry calls from sysadmins?