The Firefox team needs help to test Youtube HTML5 videos with MSE support:
We have both metrics and research which shows that people leave Firefox
if they cannot play their videos. This is in large part due to Flash. We
have a number of initiatives in flight that will directly address this,
one of which is the implementation of Media Source Extensions (MSE) to
support YouTube videos running in HTML5. Prior to the all-hands we
enabled MSE in Firefox Nightly for YouTube on Windows and Mac, and over
the past couple of weeks our engineers have been working hard on
addressing the top bugs. We are looking to get this into the hands of
our users as quickly as possible and in order to do that successfully we
need your help.
During the holidays, while you are on vacation
or in the office and have some extra cycles, install the latest Nightly,
go to YouTube.com, run videos and tell us about your experience.
Please, follow the instructions here: https://oneanddone.mozilla.org/tasks/89/
Note for Linux users:
If you are using Linux you should change these preferences from about:config:
media.fragmented-mp4.exposed=true
media.fragmented-mp4.ffmpeg.enabled=true
media.mediasource.mp4.enabled=true
media.mediasource.webm.enabled=false
Disabling webm forces YouTube to use MP4 and therefore tests the MP4
code.