1.I just uploaded a mp4 file in the sitecore backend, and when i use the html5 video tag to show it in the front end. how could i change the file type for Firefox? Firefox use the .webm format. but i think my mp4 file which uploaded could not convert to .webm file.
2.As sitecore use the .ashx extenstion name for the media, i add an extension name in the end of that ,which as below,
<source type="video/mp4; codecs=avc1.42E01E, mp4a.40.2" src="~/media/Files/Videos/sample video mp4.ashx?ext=.mp4"></source>
It works fine in IE7 and IE8, but it's still could not work in IE9. how's i could change it as a real .mp4 file for IE9?
Any help, thanks
Regarding your 2nd question:
If you're working with a recent version of Sitecore and I'd recommend running the IIS AppPool in integrated mode and change the configuration of "Media.RequestExtension" to an empty value in the web.config (or your prefered include config file).
New Sitecore Web.config value:
<setting name="Media.RequestExtension" value="" />
Or as a "patch" in an include file:
<setting name="Media.RequestExtension" set:value="" />
This setting results in media links with the original filename, which in your case would be "~/media/Files/Videos/sample video mp4.mp4"