I just installed Ubuntu 16.10 but it cannot play some videos from Twitter in Firefox. Instead, I get a message, something like

This media cannot be reproduced.

If I open the Firefox console, I see this message:

The video on this page can’t be played. Your system may not have the required video codecs for: video/mp4; codecs="avc1.42E01E mp4a.40.2"

2 Answers 2


The solution is straightforward: just install ffmpeg:

sudo apt-get install ffmpeg
  • Nope, I've got that installed already.
    – mc0e
    Jul 31, 2017 at 10:36
  • This worked for me on Ubuntu 16.04 and Firefox 57. And I still have the "Play DRM content" turned off to boot.
    – midopa
    Nov 22, 2017 at 8:07
  • not all content is drm'd, but all content requires a player.
    – michael
    Dec 14, 2017 at 4:43
  • Worked for me with Ubuntu 18
    – nabla
    May 16, 2020 at 11:54

I did have all required codecs, tools & libs installed (ffmpeg, restricted extras, etc), but still was getting a lot of (but not all) media not playing -- mostly noticeable on twitter. Some played, others did not.

I was able to resolve this by going into Firefox preferences > content > DRM content; the check box "Play DRM Content" was not checked. After checking the box and restarting firefox, these media once again started playing in firefox. (Sample test tweet to verify.)

Ubuntu 17.04 (zesty), Firefox 54.0 (64-bit)

  • Note also be sure that there's not ad blocking or other blocking (/etc/hosts) preventing the content from being displayed, e.g, blocking anything from twitter.com (etc); or if the actual image is from another site, and that site is blocked (e.g., see support.mozilla.org/en-US/questions/1076592 ). Some trial and error may be required if you want to keep most blocks in place.
    – michael
    Jul 13, 2017 at 14:22
  • That might be my problem. I'll stick with no DRM content though on principle. Oh well.
    – mc0e
    Jul 31, 2017 at 10:37
  • Enabling "Play DRM Content" doesn't fix the problem for me... only after installing ffmpeg as suggested in @brandizzi's answer and restarting FF it started playing videos (without enabling DRM).
    – Renato
    Dec 13, 2017 at 18:11
  • indeed -- playing content is dependent on having a player -- drm or no.
    – michael
    Dec 14, 2017 at 4:42

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