Would you consider posting the address of the site?

Note that if you are using HTML5 video in an MPEG-encoded format like H.264, platform support is required for decoding. This is now available across the various versions of Windows, but unfortunately is not yet standard on Mac and Linux versions of Firefox. Therefore, you need a fallback such as Flash for those platforms.

The OP posted a link in this thread: [/questions/983154]

• http://cobaltstreak.com/

Works for me on Linux.

You could consider to change the order of the source tags and list the ogv file as the first choice in case the m4v file is causing a problem on Mac.

<video width="854" height="480" title="854" autoplay >
        <source src="Moviefile/Cobalt_Intro.ogv" type="video/ogg">
        <source src="Moviefile/Cobalt_Intro-HD_720p.m4v" type="video/mp4">

Note that the Flash player seems to be missing, so fall back to Flash will fail: 404 Page Not Found

• http://cobaltstreak.com/index.files/html5video/flashfox.swf

So you may want to check that.

The good news is, the OGV video plays in Windows 7 (screen shot attached).

On the m4v file, Firefox is rather literal about these things. Your tag specifies a content type of "video/mp4" but the server is sending a header of "video/x-m4v" so Firefox seems not to be even trying to play that media.

If I open the media directly in a tab, Firefox plays it in the QuickTime plugin, eventually, after what seems to be a full retrieval, so this content type apparently does not trigger the HTML5 player.

If I save the file locally, change the extension to .mp4, and drag it onto a Firefox tab, it plays in the native HTML5 player.

So could I suggest changing the file extension to mp4 and seeing whether the server then will send the content type of "video/mp4"?

Yes - I will try this first thing tomorrow. Thanks for the quick response.

'Hi anolte,

jscher2000 has posted an answer to your question on support.mozilla.org:

Why is it so difficult to get Firefox to play web videos?

jscher2000 wrote:

The good news is, the OGV video plays in Windows 7 (screen shot attached).

On the m4v file, Firefox is rather literal about these things. Your tag specifies a content type of "video/mp4" but the server is sending a header of "video/x-m4v" so Firefox seems not to be even trying to play that media.

If I open the media directly in a tab, Firefox plays it in the QuickTime plugin, eventually, after what seems to be a full retrieval, so this content type apparently does not trigger the HTML5 player.

If I save the file locally, change the extension to .mp4, and drag it onto a Firefox tab, it plays in the native HTML5 player.

So could I suggest changing the file extension to mp4 and seeing whether the server then will send the content type of "video/mp4"?'

While some of this worked to make the video work in Firefox, it made it stop working in other browsers. While I greatly appreciate everyone's help, my main point is, that no one should to go through all of this to make a simple video work in a browser. I had no problem with IE, Safari and Chrome Simple insert and it just worked. No issues, no workarounds, it just worked.

If Firefox is going to play in the browser big league, it should consider a more standard compatible video format. If you look at the Firefox community page on the same topic, there are a lot of questions about how to make it work.

Suggestion - Do us all a favor and fix the issue and make it work as easy as it does in the other browsers.

Just a suggestion

I see that the mov file that you added as one of the source choices is missing: 404: Page Not Found

• http://cobaltstreak.com/Moviefile/Cobalt%20Intro-HD%20720p.mov

(to test this I disabled media.ogg.enabled = false)

I have the .m4v file as the primary source The .mov file as ALT Source 1 The .ogv file and ALT Source 2 And the .swf file as Flash Fallback

Movie now players fine for me in IE, Chrome, Safari and yes, even Firefox. also plays on my iPhone.