JavaScript H.264 decoder
JavaScript H.264 decoder
Written by Ian Elliot   
Tuesday, 01 November 2011

Under the codename Broadway, a JavaScript-based H.264 decoder that is intended to run naively in Web browsers has been made available on GitHub. JavaScript slow? Think again.

The decoder, which can display video at 30 frames per second on conventional hardware has been developed at Mozilla Labs by Michael Bebenita who explains how he achieved this compelling demonstration of JavaScript’s performance potential on his blog.

Alon Zakai and I managed to take an existing H.264 decoder, simplify it, and compile it with Alon's awesome Emscripten compiler, which translates LLVM bitcode to JavaScript. The result is quite remarkable, we can reach a rate of nearly 30 fps decoding video purely in JavaScript, with no real optimizations other than what Emscripten already performs. There are lots of improvements ahead, such as hardware acceleration using WebGL, parallel processing, etc.

 

H264logo

Broadway was included a presentation at the ACM’s annual OOPSLA conference by Brendan Eich. The enthusiastic response to this demonstration, a shaky video of which can be seen on yfrog,  attracted some interest and has led to the source code being published on GitHub.

As Bebenita points out in his post, this project is at an early stage and the Broadway H.264 decoder will only perform as expected in recent Firefox nightly builds, which incorporate the latest JavaScript performance improvements—particularly a new type inference mechanism that gives JavaScript execution speed a considerable boost.

According to Ars Technica the Broadway project offers useful insight into JavaScript performance characteristics, but it's not really intended for real-world usage. Mozilla’s objections to H.264 on the basis of patent encumbrances still stand and make it unlikely that users will see the video codec supported out of the box in Firefox.

But a video decoder in JavaScript - who would have predicted that and its isn't Chrome but Firefox runing it!

 

H264logo

To download:

https://github.com/mbebenita/Broadway

 

To be informed about new articles on I Programmer, subscribe to the RSS feed, follow us on Twitter or Facebook or sign up for our weekly newsletter.

Banner


Actions On Google
09/01/2017

Google has opened up Actions on Google, its developer platform for Google Assistant. It can now be used to add Conversation Actions that provide a way to give your users information, services, an [ ... ]



Christmas Is NP Hard
25/12/2016

It is official - Xmas is NP hard. See exactly how and appreciate the value of holiday algorithms.


More News

Last Updated ( Tuesday, 01 November 2011 )
 
 

   
Banner
RSS feed of news items only
I Programmer News
Copyright © 2017 i-programmer.info. All Rights Reserved.
Joomla! is Free Software released under the GNU/GPL License.
Banner