I am facing a problem using IE9 under Windows 7. When opening an HTML5 page that has a video tag of type (H.264 / MP4), the video tag will fail to play the source video.
The problem occurs when I register my own custom Media Foundation MP4 media source, and as documented I write my byte stream handler CLSID in the registry key:
\HKEY_CURRENT_USER\Software\Microsoft\Windows Media Foundation\ByteStreamHandlers\.mp4
IE9 tries to use my media source to play the video tag which fails, even though my media source sucessfully plays the same video on any Media Foundation media player application.
Are we even allowed to write a custom media source to be used in IE9?
Is there any documentation that explains this?
I think the priority must be for the Microsoft media source. It seems that is always the case for Windows Media Player.
Is that a bug in Windows 7 (in windows 8 the problem does not appear)?
Can I do something to set the priority for IE9 back to Microsoft’s media source?
I have noticed that I can work around the problem by writing Microsoft’s byte stream handler CLSID to the above mentioned registry key, and then writing my CLSID. This seems to make the Microsoft MP4 Byte stream handler be preferred against my own. Is this a safe and acceptable solution?