Gamespot most anticipated video low framerate in fullscreen

Steps to reproduce: Visit http://www.gamespot.com/videos/see-our-most-anticipated-games-of-2015/2300-6422867/ in Firefox 34. View the video in HD quality. It will play fine at first, then use the button in the lower right to enter fullscreen mode.

Actual results: In fullscreen mode, the video plays very choppy, at a very low framerate. Exiting fullscreen doesn't fix this either, the video continues to play very choppy.

Expected results: After entering fullscreen mode, the video should continue to play smoothly.

I have found a workaround for this problem. After entering fullscreen mode, click once with the mouse on the black bar at the bottom of the screen (not on a button on this bar, but on empty space on the bar). After you have clicked on the bar, the video will instantly go from very choppy playback to smooth playback.

Also reported here: https://bugzilla.mozilla.org/show_bug.cgi?id=1115195

My specs:

Intel Core i5-4590; Geforce GTX 970; OS: Windows 8.1 64-bits.

I do not use an adblocker, so it's not related to that.

Hi there, thanks for reporting. Have you experienced this issue on any other videos? If so, could you share the links to those videos. Thanks!

The problem here is flash player, it's terrible, and has no proper acceleration.

Were GameSpot keeping up with web standards, and using hardware accelerated HTML5, you wouldn't have a problem.

Also, benchmark wise, Firefox is on the slower end of browsers (still better than IE and Safari), try using Chrome or Opera.

All videos on the Game of the Year website have this problem. So, here are some other videos that have this problem:

http://www.gamespot.com/videos/jess-mcdonell-s-top-games-of-2014/2300-6422695/

http://www.gamespot.com/videos/mary-kish-s-top-games-of-2014/2300-6422625/

http://www.gamespot.com/videos/gamespot-s-goty-nominee-show-2014-the-lobby/2300-6422711/

The videos hosted on the main Gamespot site play just fine without any issues. So for example this video plays just fine: http://www.gamespot.com/videos/ces-is-a-strange-place/2300-6422931/ I've also tested a video review (http://www.gamespot.com/reviews/the-crew-review/1900-6415988/) and it also played just fine without issues.

It's a bug. My computer and Firefox are both fast enough. Flash player is fast enough. The problematic videos play just fine once I click once with the mouse on the black bar at the bottom of the screen.

Most videos on Gamespot don't have this problem at all. But all the ones hosted on the Game of the Year website do have the problem. So it's most likely a bug in the code of the Game of the Year website.