Media Fragments, Performance and MediaElementAudioSourceNode

Published on in Google Chrome, Last Week, tech, WebKit. Version: Chrome 18

The new year’s first week ended calmly, bringing in 547 commits to WebKit and 650 to Chromium. Highlights include support for temporal dimensions for media files, alignment of Safari’s JavaScript engine with ES5 and lots of performance improvements.

Engadget, among other sites, has become significantly faster in WebKit, now using 10% less CPU over the entire page load due to analyzing inline stylesheet scopes. A CSS Selector using multiple indirect adjacency combinators won’t be able to be superlinear anymore, inserting nodes into the DOM has been sped up and several other tweaks were implemented.

Sanitization of non-parsable strings in date and time input boxes is now possible in WebKit, emptying the value if an invalid value has occurred. The </script>-close tag will now be properly highlighted in View Source, and horizontal paddings and borders will be used instead of vertical ones for a CSS table’s fixed width.

Safari’s JavaScript engine aligned its behavior closer to the ECMAScript specification. The JSON object is now configurable, the parseInt method won’t parse octal numbers anymore, ThrowTypeError is now a singleton and date parsing has been made more liberal. Alexis Menard implemented getComputedStyle output for the outline, border, list-style, border-image and background properties. Finally, the Web Audio API is now able to integrate with audio and video elements throught the MediaElementAudioSourceNode object!

Eric Carlson implemented the temporal dimension portion of the Media Fragments URI specification. This allows you to append a formatted hash-string to any media file’s URL selecting which portion of the file should be played. For example, this plays the fourth until the twelfth second: video.webm#t=4,12.

Other changes which occurred last week:

And that’ll be all for now! Lets get back on the Monday-track for updates starting next week!

9 Responses to “Media Fragments, Performance and MediaElementAudioSourceNode”

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drew

January 12, 2012 at 11:47 pm

What’s “adjenceny”? Adjacency? :)

Also, no summary of Chromium changes? The Chromium Authors (© 2006-2012) wouldn’t be brewing up anything super secret now, would they?


Peter Beverloo

January 12, 2012 at 11:49 pm

Ah, thanks, changed.

No, there just wasn’t anything really interesting for developers to share. Lots of changes related to coverty, cleaning up and general code cleanness.


demonstrate ultimate…

[...]Media Fragments, Performance and MediaElementAudioSourceNode « Peter Beverloo[...]…


[...] particular, the spatial dimension part. The temporal dimension portion was implemented last year in Chrome and Firefox but the spatial dimension isn’t supported in any current browser as of the time [...]


[...] particular, the spatial dimension part. The temporal dimension portion was implemented last year in Chrome and Firefox but the spatial dimension isn’t supported in any current browser as of the time [...]


[...] particular, the spatial dimension part. The temporal dimension portion was implemented last year in Chrome and Firefox but the spatial dimension isn’t supported in any current browser as of the time [...]