For live videos, a lot of people use services that require Flash Player. I'm
not sure of the technical details of why, but these streams can't be viewed
in the free world, other than a few exceptions where you can trick them into
giving you an RTSP link that works. Send a message to people who use these
services and ask them to use something like IceCast instead; IceCast works
with any video player, even a standard HTML5 video player.
If you want to check for an RTSP link, disable the Gnash plugin (called
"Shockwave Flash" in the plugins list). Install the User Agent Switcher
extension and identify yourself as some Android browser (try a few different
ones), as an iPad, and as an iPhone. My experience is they usually try to
direct these users to download special proprietary apps, but sometimes they
will give you an RTSP link somewhere, and the UnPlug extension will be able
to find that link. Then, if it's a good RTSP link, VLC will be able to show
it. I found a few months ago that Livestream would give such an RTSP link,
for example; so far it's the only example I'm aware of where it works. But
it's something you can try.
For normal video streaming, make sure you disable the Gnash plugin (called
"Shockwave Flash" in Abrowser's list of plugins). Many video hosts now offer
fallback HTML5 players if Flash is unavailable. If they don't, you may want
to ask the video host to correct this problem. Another thing you can try is
Lightspark, which is a project to replace more recent Flash versions than
Gnash; I find that it rarely works, but in many cases it will at least make
it possible for the Flash Video Downloader extension to download the video.
Note that none of these methods will work if the video host uses digital
restriction mechanisms.[1] This includes Netflix, Hulu, and probably some
others I'm not aware of.
[1] http://www.defectivebydesign.org
