Video Problems - Media Format Not Supported

 I am unable to watch about 50% of the Chess.com videos because I get a black screen error message on my Windows PC that says "Media Format Not Supported".   So what video format is being used for these videos?

What browser are you using? Do you have specific examples?

Using Internet Explorer and Windows 7.  Examples are:  GM Rabachess opening video "The King's Indian Destroys the Center and GM Vegasicilia "Making a Middle Game Crisis" (posted today). 

What version of Explorer? It very well could be the browser.

If you have Firefox or Chrome, try that; both loaded for me on Chrome.

 Using Explorer 11.  Wondering why about half of the videos load okay and error messages on the rest.  Why the different formats?  Don't like using Chrome at home because it always seems to put strange cookies on my computer but use Chrome at work sometimes so might try it tomorrow on the office computer. 

I'm having the same problem. Internet Explorer 11.0 on Windows 7.

I tried Chrome at work and got the same error message.....  Very frustrating - still can't watch the videos.

Okay this is getting more frustrating.  I can only watch about 1 in 10 video attempts.  The rest get the error message.  The video instruction is one of the main reasons that I joined Chess.com.  This must be a common problem.  Doesn't anyone know what format these other videos require and why I am getting the error messages?!?

@C_Atrox - I sent you a message to hopefully get some more information! Thanks for your help!

They're MP4 files; they use H.264 video and AAC audio. For Internet Explorer, decoding of these videos is dependent on the codecs installed on your machine. It's possible that your system or its installed codecs aren't able to decode large resolution H.264 video (I noticed the problem videos mentioned are over 1100x1100. In Windows 7, according to some Microsoft API documentation, certain APIs, and therefore certain applications depending on them, can't decode H.264 greater than 1920x1088).

Thanks Williamfwm for the info.  So it looks like the videos are just not compatible with Windows 7.  Seems kind of amazing because I am sure there are a lot of Windows 7 users out there.  You mentioned Internet Explorer - any chance of getting these to work with Chrome?

The machine I tested on loaded both the example videos fine and I'm on Windows 7 and tested on Chrome.

I have the same problem under Windows Vista. I found out it is possible to play these videos with the VLC media player. In the html source code of the web page, you find the link to the mp4 video file. You can either stream the video using VLC media player or you can download it and open it with VLC media player after the download has finished.

In Firefox, if you set media.mp4.enabled to false, this will force Adobe Flash to be used instead and the videos will just play fine in Firefox.

The VLC media player uses built-in codecs, so no separate codec packs are needed and the Platform Update Supplement for Windows Vista (KB2117917) adds h264 support to Windows Vista. By the way, my computer plays h264 videos just fine in Firefox, just the videos on chess.com do not work for me, maybe because of their strange resolution.