Cobalt Version Changelog

This document records all notable changes made to Cobalt since the last release.

Version 12

  • Add support for touchpad not associated with a pointer

    This adds support for input of type kSbInputDeviceTypeTouchPad for touchpads not associated with a pointer.

Version 11

  • Splash Screen Customization

    The Cobalt splash screen is customizable. Documents may use a link element with attribute rel=“splashscreen” to reference the splash screen which will be cached if local cache is implemented on the platform. Additionally fallbacks may be specified via command line parmeter or gypi variable. For more information, see doc/

  • Introduce C++11

    C++11 is now used within Cobalt code, and so Cobalt must be compiled using C++11 toolchains.

  • Update SpiderMonkey from version 24 to 45; support ECMAScript 6

    The Mozilla SpiderMonkey JavaScript engine is rebased up to version 45, and thus ECMAScript 6 is now supported by Cobalt. You will need to modify your gyp_configuration.gypi file to set 'javascript_engine': 'mozjs-45' to enable this.

  • Fetch/Stream API

    Cobalt now supports the Fetch/Stream API.

  • On-device Speech-to-Text support

    Support for utilizing the new Starboard speech recognizer interface in order to allow for on-device speech-to-text support is now added. The Starboard interface is defined in starboard/speech_recognizer.h.

  • Mouse pointer support

    Cobalt now supports pointer events and will respond to Starboard kSbInputEventTypeMove events. These will be passed into the WebModule to be processed by JavaScript.

  • Custom Web Extension Support

    Cobalt now allows platforms to inject a custom namespace property into the JavaScript global window object visible to the web apps. This allows for custom web apps to interface with custom C++ code written outside of Cobalt common code. See doc/ for more details.

  • Playback Rate

    Cobalt now supports adjusting the video playback rate.

  • AutoMem - Memory Configuration

    AutoMem has been added which assists developers in tuning the memory settings of the Cobalt app. On startup, memory settings are now printed for all builds except gold. Memory settings can be altered via the command line, build files and in some instances the Starboard API. For more information, see cobalt/doc/

  • Page Visibility API Support

    Cobalt now supports the page visibility API, and will signal visibility and focus changes to the web app as the process transitions between Starboard lifecycle states. See the new Application Lifecycle Integration document for more details.

  • Opus Support

    Added support for providing Opus audio-specific config to Starboard. Requires Starboard 6.

  • Linux build now supports 360 video

    The Linux build linux-x64x11 now supports 360 video, and can be used as a reference implementation.

  • Stop the application if not retrying after a connection error

    A positive response from kSbSystemPlatformErrorTypeConnectionError now indicates that Cobalt should retry the failed request. Any other response now causes Cobalt to call SbSystemRequestStop.

  • Frame rate counter

    A frame rate counter is now made accessible. It actually displays frame times, the inverse of frame rate. In this case, 16.6ms corresponds to 60fps. It is accessible both as an overlay on the display by the command line option, “--fps_overlay”. The data can also be printed to stdout with the command line option “--fps_stdout”. The frame rate statistics will be updated each time an animation ends, or after 60 frames have been processed. Both command line flags are available in Gold builds.

  • Add support for rendering kSbDecodeTargetFormat1PlaneUYVY (YUV 422)

    Decode targets with the format kSbDecodeTargetFormat1PlaneUYVY will now be rendered by Cobalt. This will allow decoders that produce YUV 422 UYVY video frames to now efficiently support 360 video.

  • Preload Support

    Support for preloading an application with no graphics resources. See the new Application Lifecycle Integration guide for more details.

  • Improvements and Bug Fixes

    • Fixed position elements given correct draw order without requiring z-index.
    • Overflow-hidden correctly applied when z-index is used.
    • Padding box forms containing block for fixed position elements within transforms.
    • Determine whether a font is bold in more cases, so synthetic bolding isn't incorrectly applied.
    • Fix bug where decoding images with large headers would fail.
    • Include missing CSS transforms in GetClientRects() calculations.
    • CSS Transitions and Animations not resetting properly when adjusting display: none on an element.
    • offset_left and similar properties are no longer cause many expensive re-layouts to query.
    • Fix bug where pseudo-elements were “inheriting” the inline style of their parent elements as if it were their own inline style.

Version 9

  • Improvements and Bug Fixes
    • Non-fixed position elements given correct draw order without requiring z-index.