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stream not download video files to windows media player


When I choose an m4v file on the 'net, FF *downloads* instead of *streams* the file to Windows Media Player; IE9 and Chrome immediately launch WMP and begin streaming the video.

 I have the latest WMP plugin, and I have set the default program to WMP for M4V files.

Running Windows 7 and FF 15.0.1.

Additional System Details

Installed Plug-ins

  • Shockwave Flash 11.5 r502
  • Adobe PDF Plug-In For Firefox and Netscape 10.1.5
  • Google Update
  • 4.1.10329.0
  • The plug-in allows you to open and edit files using Microsoft Office applications
  • Office Authorization plug-in for NPAPI browsers
  • np-mswmp


  • User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/20100101 Firefox/15.0.1

More Information

Tyler Downer
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1164 solutions 6635 answers

Please update to Firefox 18 Update Firefox to the latest version

Then Reset and retest. Reset Firefox – easily fix most problems

  • Top 10 Contributor
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10747 solutions 96724 answers

Is that file played embedded on a we page or is this a link?

With which content (MIME) type is the file send by the server if you check the Net log in the Web Console (GET entry fro the media file)?

Helpful Reply

It's simply a link pointing to the m4v file on the website.

I don't understand why IE9 and Chrome will stream it immediately no problem, but FF is compelled to download the entire file first. That's what I'm trying to fix.

I don't want to embed WMP on the page, since I assume that blocks out Safari users(?) I suppose if I embed any player it should be Flash Player, which is pretty universal. But I would like to stick to the MP4 format if I can.

I don't know how to make sense of the information on the console.

Thanks for any help.


Question owner

I updated and reset.

Same problem: FF wants to download the entire file before launching WMP.


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10747 solutions 96724 answers

Does that file already has the media content or is the URL of the streamed file stored in the m4v file?

If there is a link in the file then Firefox should only pass the file with the link and not the full media file to the player..

Question owner

Thanks for the reply, but I'm not sure what you're asking. The file on the server is simply an MP4 video file with name "vidTest.m4v" On my webpage I have a straight link pointing to it, eg.: <a href="vidTest.m4v">"MP4 Video Test"</a> in the same directory as the html that calls it.

If there's more I need to include with either in the link to "vidTest.m4v" or the m4v file itself to make FF immediately stream the file to WMP, could you exemplify it for me?

Thanks! --Dave

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10747 solutions 96724 answers

This is about using a playlist file format like .m3u that stores the location of the file.

bcomnes 0 solutions 1 answers

Helpful Reply

I am having this issue to, and I am sorry, but telling the internet to pass around playlist files of media location urls does not solve anyone's problem here.

davidla985: Here is what I found out. go to about:config in your URL bar filter for "media.windows-media-foundation" Change it to true.

You might have to be running FF beta, I am not sure.

Now firefox will stream the MP3 or whatever files supported by your system in a tab without downloading first, just like chrome.

As far as getting a link to a file to open immediately in another app, like IE has for years, I cannot find a way to do that. It's been that way for so long, I presume either mozilla has to fix the issue, or someone could write an addon to get that behavior. Let me know if you come across anything that can get this working.