The HTML5 Extension for Windows Media Player Firefox
Plug-in is an add-on that enables Firefox users to play
H.264-encoded videos on HTML5 pages by using the built-in
capabilities found in Windows 7. This Extension adds to the
functionality of the extremely popular earlier
Windows Media Player Plug-in for
Firefox to enable web pages that use the emerging
- Requires Firefox 4.0 or later
- Windows 7
Install the Add-on
Windows Media Player Firefox
Plug-in Release Notes
A copy of the license agreement is available here (A copy of the file is also
installed with the Add-on).
The Extension is based on a Firefox Add-on that parses HTML5
pages and replaces Video tags with a call to the Windows Media
Player plug-in so that the content can be played in the browser.
The Add-on replaces video tags only if the video formats specified
in the tag are among those supported by Windows Media Player. Tags
that contain other video formats are not touched.
In some cases Firefox might fail to play a video even if the
Add-on is correctly installed because the page might be using a
call to canPlayType to determine if the browser can play H.264
content. Typically the check is done either using
createElement('video') or getElementsByTagName('video') and then
call canPlayType('video'mp4'). In both cases the call will return
empty string even if the Add-on is installed and the browser could
play H.264 videos.
The current version of the Add-on still uses the Windows Media
Player Plugin APIs to control video playback so there are some
differences between the methods/properties defined in the emerging
HTML5 standard and those available in the Windows Media Player
We are working to see if a solution can be found for these