[CentOS] MP4/H.264 codec for Firefox?

Sun Oct 1 10:28:28 UTC 2017
hw <hw at adminart.net>

Roman Kennke <roman at kennke.org> writes:

> Hello,
> I am trying to get MP4/H.264 playback in Firefox to work on my CentOS
> laptop (for vimeo).
> I installed the gstreamer plugins as described here:
> https://wiki.centos.org/TipsAndTricks/MultimediaOnCentOS7
> (No, I did not install Flash, VLC and all the other stuff. I only want
> HTML5 MP4 playback..)
> I enabled the nux repos. I did install all available gstreamer
> plugins, i.e. -good -bad -ugly -ffmpeg etc. No success.
> Has anybody got mp4 playback working?
> Here's a test page:
> https://www.quirksmode.org/html5/tests/video.html

All movies on that page play without having taken any particular
precautions in Seamonkey (I dislike Firefox).

However, I have ffmpeg and mplayer installed (compiled from source
because there aren´t packages for those).  I don´t know if any of them
are being used by Seamonkey.

yum list installed | grep gstream
gstreamer.x86_64                       0.10.36-7.el7                   @base    
gstreamer-plugins-base.x86_64          0.10.36-10.el7                  @base    
gstreamer-tools.x86_64                 0.10.36-7.el7                   @base    
gstreamer1.x86_64                      1.10.4-2.el7                    @base    
gstreamer1-plugins-base.x86_64         1.10.4-1.el7                    @base    

Those must have been installed for dependencies; I didn´t install them

"Didn't work" is an error.