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

Sun Oct 1 16:13:33 UTC 2017
Roman Kennke <roman at kennke.org>

Am 01.10.2017 um 12:28 schrieb hw:
> 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
> explicitly.

Installing ffmpeg-libs solved it for me. I suspect that FF links against 
ffmpeg-libs or via gstreamer-ffmpeg or some such.

Thanks, Roman