This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

No H.264 support in HTML5, Firefox 49, Linux

more options

Hi, my Firefox doesn't have support for H.264 decoding, although ffmpeg and other software compiled with support for it. According to https://www.youtube.com/html5 there is no H.264 and MSE & H.264 support. On pages with html5

Hi, my Firefox doesn't have support for H.264 decoding, although ffmpeg and other software compiled with support for it. According to https://www.youtube.com/html5 there is no H.264 and MSE & H.264 support. On pages with html5 <video> tag with type="video/mp4" Firefox tells "Video format or MIME type is not supported". At about:support page there is line: "Supports Hardware H264 Decoding = No; Failed to create H264 decoder". I have recompiled Firefox with --enable-debug, and now I see the error "[6748] WARNING: Unable to create a decoder, no platform found.: file /var/tmp/portage/www-client/firefox-49.0/work/firefox-49.0/dom/media/platforms/PDMFactory.cpp, line 153". Video driver is the nvidia proprietary driver. I also ask this question in this thread (with additional info related to distrib) https://forums.gentoo.org/viewtopic-t-1054580.html. Please help.

Asịsa ahọpụtara

I have found the cause of the problem, it is Plex Media Server. This package contains libavcodec.so.57 which Firefox tries to link against and fails to do so (system-wide installed ffmpeg contains libavcodec.so.56).

Gụọ azịza a na nghọta 👍 0

All Replies (2)

more options

Asịsa Ahọpụtara

I have found the cause of the problem, it is Plex Media Server. This package contains libavcodec.so.57 which Firefox tries to link against and fails to do so (system-wide installed ffmpeg contains libavcodec.so.56).

more options

(For the record) For details on the problem and its solution, see this thread that nshibalov posted on the Gentoo Forums: https://forums.gentoo.org/viewtopic-p-7991240.html?sid=38ed7080bf31ac898795875a04c62f4e [SOLVED] Firefox 49, no H.264 support