Don't bother with the flash plugin for youtube. From the OWB.readme:
Youtube special notes
---------------------
There are a few things to know about Youtube, since it tends to change
(or rather break) quite often.
Youtube introduced a new way to play media without using Flash: HTML5 video.
This service isn't enabled by default nor autodetected, so it has to be
enabled by going to http://www.youtube.com/html5 and clicking the subscription
link (no account needed, only a cookie will be set).
There are a few more important elements to consider:
- Youtube recently added a silly user-agent check, which means the HTML5 player
will only be enabled if the user-agent matches. So, for OWB, the solution is to
spoof as "Safari" in OWB preferences -> Network.
Update (2010-09-01): it seems they reverted this change, so the Safari user-agent
isn't needed anymore (so far).
- Youtube broke the fullscreen mode that worked just nicely before, so a script is needed
to workaround this. This is done by going to Windows->Scripts and adding the
"Scripts/youtube_fullcreen_fix.js" userscript. This fullscreen mode is particularly
important, since OWB uses overlay output in this mode, which makes it about 3 times
faster, synchronized on VBL, and smoother as well, compared to windowed mode.
- Not all Youtube links are available as HTML5 yet. Fortunately, there's a way
to "convert" the remaining Flash-only links to HTML5 by adding the "Script/Youtube.js"
script in Windows->Scripts. When this script is enabled, the Flash element on Youtube
is removed, the video direct URLs are retrieved, and a HTML5 <video> tag is added,
playing the video file, without Flash. Direct links to the video are also displayed
below the video. Please note that if the Flash plugin is not installed, a "Get Flash"
message will be shown over the video, and will also prevent the video from being started
automatically, which means one of the links below the video will have to be clicked to
play the video. Also note that format "18" (mp4) is the most efficient one, since FLV
ones can have some speed and synchronisation issue when seeking.
- Since Youtube can break stuff anytime, be sure to check for updated userscripts in
http://fabportnawak.free.fr/OWB/scripts/ if something broke.
"We live, we die, we laugh, we cry"