Manually Install OpenH264 codec for Firefox

This post will show you how to install the OpenH264 Video Codec in Firefox. It is very useful for installing it when Firefox fails to do so automatically or for fine tuning your version.

The solution I found, by referencing a previous profile, is as follows:

• Download a relevant release here: https://github.com/cisco/openh264/blob/master/RELEASES
• Open with archiver and extract the .dll to %appdata%/mozilla/firefox/profiles/xxxxx.default/gmp-gmpopenh264/1.2 (change 1.2 to desired version)
• Rename to gmpopenh264.dll
• Create a new file in that directory called gmpopenh264.info , edit this file and put this info in there:

  Name: gmpopenh264
  Description: GMP Plugin for OpenH264.
  Version: 1.2
  APIs: encode-video[h264], decode-video[h264]

• Open prefs.js in the firefox user folder and add

  user_pref("media.gmp-gmpopenh264.version", "1.2");

After following these steps you will have the OpenH264 codec enabled.