Only 'h.264' and 'MSE & h.264' are disabled in youtube html5 video player support.
I spotted this issue right after I installed Windows 10, and still haven't been able to figure out why. I did some research on google, but none of them were the case for firefox 39 (and 40.0 because I just updated!), and Windows 10.
What I believe is that Firefox has a built-in Open H.264 codec so I don't need additional installations or tweaks to enable h.264 support in the recent build. However, even if I can clearly see the codec installed in the plug-in list, it seems something is missing in my Firefox accroding to the support page.
I already tried clean reinstall, and even checked on the safe mode but had no luck so far. I wish I could get some help or any advice. Thanks in Advance!
Modified
Chosen solution
Actually... Firefox needs the Windows Media Foundation to decode H.264.
First, let's see whether this is a YouTube-only issue: can you play the H.264 video on this test page: http://www.quirksmode.org/html5/tests/video.html
If it doesn't work on any site, do you maybe have an N or KN version of Windows that doesn't have the Media Feature Pack bundled in? Please see: https://www.microsoft.com/en-us/download/details.aspx?id=48231
Read this answer in context 👍 25All Replies (2)
Chosen Solution
Actually... Firefox needs the Windows Media Foundation to decode H.264.
First, let's see whether this is a YouTube-only issue: can you play the H.264 video on this test page: http://www.quirksmode.org/html5/tests/video.html
If it doesn't work on any site, do you maybe have an N or KN version of Windows that doesn't have the Media Feature Pack bundled in? Please see: https://www.microsoft.com/en-us/download/details.aspx?id=48231
Thank you! Jscher2000! Your assumption was correct. After I install the package, the support page shows all clear.
I wish I could have better knowledge about Media Foundation maybe I could have eased my suffer.
Anyway, again I really appreciate for this. :D