I'm primarily concerned about this question for Ubuntu on Toshiba AC100 (ARM), because a Flash plugin for browsers is not available as a working package for Ubuntu on AC100, but it is a general question which would apply to any Ubuntu system where one doesn't want to use the prorietary Flash plugin and the format.
At http://vk.com (VKontakte -- a popular Facebook clone from Russia), video and audio are usually played by means of Flash. What if one doesn't want to mess with the proprietary Adobe's flash plugin, is it possible to play video and audio at VKontakte?
(As we know, in the case of YouTube, video playback can be done by means of HTML5 as an alternative to Flash. And indeed, I could play video from YouTube in Firefox in Ubuntu 12.04 for AC100.)
Is the situation for VKontakte worse than for YouTube?
I have found the following answers about HTML5 and VKontakte (in Russian) from 2010 -- http://otvety.google.ru/otvety/thread?tid=405ffaec80c737f7 and http://habrahabr.ru/company/vkontakte/blog/93599/ -- saying that VKontakte encodes the video with H.264, and because of this, HTML5 playback will work only in Google Chrome and Safari (important for iOS), but not in Firefox and Opera which don't support H.264.
I've also found the following statemnent concerning H.264 support in browsers -- http://en.wikipedia.org/wiki/H264#Controversies :
"In January 2011, Google announced that they were pulling support for H.264 from their Chrome browser and supporting both Theora and WebM/VP8 to use only open formats. However, as of September 2012, Google has not followed through with this announcement and still supports H.264 in their Chrome browser through FFMPEG. No official statement was released on the matter.
On 18 March 2012 Mozilla announced that it will support H.264 in Firefox on mobile devices due to prevalence of H.264-encoded video and the increased power-efficiency of using dedicated H.264 decoder hardware common on such devices."
So, the situation is not clear: is Chromium expected to abandon the support for H.264, and has Firefox not yet implemented it? Is it possible to play video at VKontakte in one of the browsers in Ubuntu on AC100 now?
(And what about audio at VKontakte?)
(I've also posted this question to https://answers.launchpad.net/ac100/+question/208747 .)