Archive for December, 2012

VP9 and Opus, Background Position Offset and Ruby Positioning

Published on in Google Chrome, Last Week, tech, WebKit. Version: Chrome 25

This update discusses the 1,522 WebKit and 2,131 Chromium changes that landed in the past two weeks, totaling up to 3,653 changes.

Chromium updated the libvpx library to include support for an early version of the VP9 decoder, the successor of the VP8 codec that’s currently used by WebM. Furthermore, though still behind a flag (also available in about:flags), WebM files containing audio streams using the Opus codec are now supported as well.

The Toolbar Icons in Web Inspector won’t be shown by default anymore. The gear icon immediately goes to the Settings dialog again. Newly added items to the Network Panel will now be applied to filtering and cookies can be sorted by their size again. The viewport-related warning messages have been cleaned up, a new warning has been added for scripts blocked by @sandbox and messages created by console.time and timeEnd() can now be filtered out.

Support has been added for the “widows”, “orphans” CSS properties, as well as for the “ruby-position” property. The text-orientation property now supports the “sideways-right” value and text decorations will now work correctly when text-combine is being used as well. Furthermore, out-of-range values will now be clamped to values the supported range. Applying SVG filters to elements through the url() syntax will now work even when the filter isn’t available yet, and CSS Exclusions’ shape-inside is now supported for multiple-segment polygons.

Elliot moved generated content in :before and :after CSS pseudo-elements to the DOM, which also means that supporting animations and transitions on them is close. The Shadow DOM’s ShadowRoot constructor is gone, XMLHttpRequests for blob data will now set their Content-Type header accordingly and status events will now be fired for <link rel=prerender> elements. The Web Audio API now supports an offline audio context and the ::cue pseudo-element for video elements now is supported as well.

Support for in-band text tracks is now available on the Mac port, and plumbing has been added to allow deferring displaying of text tracks to the embedder.

Following the final pieces of it’s implementation, Alexis enabled support for the new background-position offset syntax on several platforms before enabling it by default, and removing the feature flag altogether. Meanwhile Tab started on aligning WebKit’s gradient implementation with the specification, towards unprefixing.

As for more experimental features, work on implementing CSS Grid Layout continues with improved parsing and layouting capabilities. Rick started working on supporting -webkit-image-set() on cursors, too.

Other changes which occurred these weeks:

This will be the last update of 2012. Thank you for reading, have a Merry Christmas and a Happy New Year!!

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Blending on 2D canvas, :read-only for dates and times and work on Grid Layout

Published on in Google Chrome, Last Week, tech, WebKit.

This update talks about the 690 WebKit commits and 1039 Chromium commits which landed last week.

A canvas’ 2D context’s globalCompositeOperation property now also accepts the various blending modes. The unpause() method on a MediaController object is now supported. Removing non-existent cues from a text track will raise an exception, and a media element’s textTracks property will now reflect the associated <track> element.

The :read-only CSS pseudo-class has been updated to work with date and time input types as well. The -webkit-mask-attachment property has been removed and the masking size has been added to the -webkit-mask shorthand. WebKit’s Multiple Column implementation now accepts “none” as the value for column-span rather than just one, and tables have started respecting the max-height property.

As for experimental features, Julien is continuing his work to implement the CSS Grid Layout Module in WebKit, and landed several more patches. Dave also landed another patch for the new Multiple Column implementation, and CSS Shaders’ input colors will now be clamped before being blended. More tests have been added for the CSS Device Adaptation implementation, and values provided through the meta tag won’t be clamped anymore.

Other changes that occurred last week:

  • An OpenCL-based implementation of several filter effects has been added.
  • A basic implementation of the Web Audio API’s MediaStreamAudioDestinationNode landed.
  • Printing in a custom font on a <canvas> object can now also fall-back to other fonts if it’s unavailable.
  • It’s now possible to run WebKit’s performance tests on Chromium for Android.
  • In order to make performance profiling easier, the run-perf-tests script now accepts a –profile option.
  • A feature flag has been added for an implementation of the HTML <template> element.
  • The appearance of the Media Gallery dialog has been updated to a new style, as has print preview.
  • Partytime has been brought back to WebKit!

On to Rome for the weekend :).

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