I\'m having some trouble displaying HTML5 video in IE9, I added the different types to my htaccess
AddType video/ogg .ogv AddType video/mp4 .mp4 AddType vide
Are you trying to use this on IIS?
If so, you have to add the appropriate mime types to recognize your video files:
Here's some markup that works for me in IE9 (in the root folder, i have a "video" folder with my files):
Video Demo