Why isn't this video player on my Firefox?

2

1

The video on this webpage works on my tablet's and a 2nd computer's Firefox browsers, but not on my main computer's Firefox.

  • Tablet: Android 5.0, Firefox 39
  • 2nd PC: Windows 7 x86, Firefox 40.0.3
  • Main PC: Windows 7 x64, Firefox 40.0.3

I can't figure out why the video won't play on my main PC. I have done the following:

  1. Made sure that Cisco's OpenH264 video codec is set to "Always Activate"
  2. Disabled all my security addons
  3. Restarted Firefox in safe mode (this disables all addons
  4. Refreshed Firefox to default state with about:support >> Refresh. This removes all extensions and their data and resets all about:config settings to default

It's always the same thing. In place of the video, I see a grey overlay with the message No video with supported format and MIME type found. The developer's console (CTR+SHIFT+K) shows two warnings

  1. Specified "type" attribute of "video/mp4" is not supported. Load of media resource test.mp4 failed.
  2. All candidate resources failed to load. Media load paused.

I don't know what else to do. Ideas?

Additional Info:

  1. The .mp4 file from the page plays normally from the desktop (out of FF)
  2. I tried another video with no luck. The .mp4 video on this page throws the same error.

Fixed: Thanks to @karel for pointing me in the right direction. My version of Windows (7 N) lacked some media features that Firefox relies on. I had to install the Windows Media Feature Pack.

BeetleJuice

Posted 2015-09-02T07:10:50.773

Reputation: 677

1Idea: Test whether a different online .mp4 video plays or not in your main computer's Firefox. – karel – 2015-09-02T07:21:35.780

Great idea. This page has a video player with video/mp4 as the first option and video/ogg as a 2nd. The developer console shows error Specified "type" attribute of "video/mp4" is not supported. Load of media resource mov_bbb.mp4 failed. (the video still plays but it's the .ogg, not .mp4 that gets played). The error does not appear on my 2nd PC

– BeetleJuice – 2015-09-02T07:37:59.517

Try: Type about:preferences#advanced<Enter> in the address bar. Under Advanced, Select General. Look for and turn off Use Hardware Acceleration. – Divin3 – 2015-09-02T07:40:09.177

Good thinking. Unfortunately it made no difference. – BeetleJuice – 2015-09-02T07:47:37.050

Answers

1

You may be needing this in case you do not have support for MP4 files in Firefox:

Windows Media Feature Pack for Windows 7 N and for Windows 7 KN:

Also make sure that these Firefox preferences have the default value. You already tried resetting all about:config settings in Firefox to the default value, but it didn't work.

  • media.windows-media-foundation.enabled
  • media.directshow.enabled

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

If you have a similar problem or a problem with a different audio/video codec not playing in Firefox for Windows:

Source: Mozilla Support Forum: How can I make mp4 videos play in Firefox?

karel

Posted 2015-09-02T07:10:50.773

Reputation: 11 374

Karel I think you're unto something. My main PC has OS Windows 7 N. Do you think I can get the functionality needed without having to install the full Media Player & associated programs? Is there a leaner solution you can think of? (I chose 7 N to avoid the junk) – BeetleJuice – 2015-09-02T08:18:47.943

To uninstall Windows Media Player in Windows 7: Click "Start" and type "windows features" into the search field; then press Enter to open the Windows Features dialog. Clear the checkmark next to "Windows Media Player" and confirm that you want to turn off (or uninstall) Windows Media Player. Click "Restart Now" to shut down your computer and start it up again. – karel – 2015-09-02T08:21:48.030

So you suggest that I install the update you linked to (which will install WMP + other stuff), then disable/uninstall WMP? (haven't installed the update yet because I know things are much easier to install than they are to uninstall, and it's a big chunk of software) – BeetleJuice – 2015-09-02T08:31:07.790

Yes, I suggest that you start off by installing the full update, uninstall what you don't need, one program at a time and then check if uninstalling that program didn't break anything. – karel – 2015-09-02T08:54:24.110

You, sir are the reason I love the internet. I installed the Media Feature Pack, tested that things worked (they do!) then went into Windows Features where a new group of features titled Media Features had appeared containing Windows DVD Maker, Media Center and Media Player. I unchecked the whole group, restarted the PC and... things still work!! I recommend you add the following link to your answer: https://support.mozilla.org/en-US/kb/fix-video-audio-problems-firefox-windows

– BeetleJuice – 2015-09-02T09:11:13.483

Asked: 2015-09-02T07:10:50.773

Viewed: 14 131 times

Active: 2017-06-04T01:58:16.803