Starboard Version Changelog

This document records all changes made to the Starboard interface, up to the current version, but not including the experimental version. This file will be updated each time a new Starboard version is released. Each section in this file describes the changes made to the Starboard interface since the version previous to it.

NOTE: Starboard versions 3 and below are no longer supported.

Experimental Version

A description of all changes currently in the experimental Starboard version can be found in the comments of the “Experimental Feature Defines” section of configuration.h.

Version 11

Add arguments to SbMediaIsVideoSupported.

Add arguments for profile, level, bit depth, color primaries, transfer characteristics, and matrix coefficients. See comments of SbMediaIsVideoSupported for more details. Also, the function SbMediaIsTransferCharacteristicsSupported() is no longer necessary and is removed.

Add support for AC3 audio.

Replace kSbMediaVideoCodecVp10 with kSbMediaVideoCodecAv1.

Add a new enum kSbPlayerErrorMax in starboard/player.h.

Add new parameter max_video_capabilities to SbPlayerCreate().

This gives the application the option to specify to the SbPlayer object what the maximum video specifications will be, as a hint to the platform on how to allocate resources for the SbPlayer. For example, if the player will never exceed a 240p playback resolution, then a software decoder may be initialized. Please see comment in SbPlayerCreate() for more details.

Refactor SbPlayerSampleInfo to reuse SbPlayerSampleInfo in filter based player.

Additionally, add audio and codec info for every sample.

Introduce audio write duration

Add a function SbMediaSetAudioWriteDuration() to starboard/media.h which communicates to the platform how much audio will be sent to the platform at a time.

Introduce Cobalt Extensions using the SbSystemGetExtension interface.

Cobalt extensions implement app & platform specific functionality.

Deprecate unused function SbSystemClearPlatformError().

Deprecate kSbEventTypeNetworkDisconnect and kSbEventTypeNetworkConnect.

Add support for using C++11 standard unordered maps and sets.

By setting SB_HAS_STD_UNORDERED_HASH to 1, a platform can be configured to use C++11 standard hash table implementations, specifically, using:

  • std::unordered_map<> for base::hash_map<>
  • std::unordered_multimap<> for base::hash_multimap<>
  • std::unordered_set<> for base::hash_set<>
  • std::unordered_multiset<> for base::hash_multiset<>


Adds support for specifying screen diagonal length.

When a platform knows its physical screen diagonal length, it can now provide that data to the application via SbWindowGetDiagonalSizeInInches().

Add support for device authentication system properties.

The system properties kSbSystemPropertyCertificationScope and kSbSystemPropertyBase64EncodedCertificationSecret have been added to enable client apps to perform device authentication. The values will be queried by calls to SbSystemGetProperty() in starboard/system.h. An alternative to providing the kSbSystemPropertyBase64EncodedCertificationSecret property is to implement the SbSystemSignWithCertificationSecretKey() function, enabling the key to remain private and secure.

Add support for SbThreadSampler and SbThreadContext.

This is helpful for enabling the implementation of sampling-based profilers. A full implementation is only required if the new function SbThreadSamplerIsSupported() returns true. A valid implementation will need to implement the new starboard/thread.h functions, SbThreadContextGetPointer(), SbThreadSamplerIsSupported(), SbThreadSamplerCreate(), SbThreadSamplerDestroy(), SbThreadSamplerFreeze(), SbThreadSamplerThaw().

Introduce functions for supplying suggestions to the on screen keyboard.

A new API in starboard/window.h is introduced which declares the functions SbWindowUpdateOnScreenKeyboardSuggestions() and SbWindowOnScreenKeyboardSuggestionsSupported(). This is only relevant if SB_HAS(ON_SCREEN_KEYBOARD).

Introduce new file error code kSbFileErrorIO.

The new code, added to starboard/file.h, should match “EIO” on Posix platforms.

Move the definition of FormatString() from starboard/string.h to starboard/format_string.h.

Make the decode target content region parameters floats instead of ints.

The SbDecodeTargetInfoContentRegion struct is modified to accept floats instead of ints. The primary motivation for this change is to make it so that on platforms where it is difficult to obtain the width and height of a texture, we can still correctly identify a precise fractional “normalized” content region with the texture width and height set to 1.

Add kSbSystemPropertyOriginalDesignManufacturerName enum value.

This change also deprecates kSbSystemPropertyNetworkOperatorName. The kSbSystemPropertyOriginalDesignManufacturerName value will represent the corporate entity responsible for the manufacturing/assembly of the device on behalf of the business entity owning the brand.

Cross-platform helper Starboard definitions factored out of core interface.

Cross-platform helper Starboard definitions refactored out of /starboard/ and into /starboard/common/. In order to more explicitly identify the core Starboard API, multiple files, or parts of them, were moved into the static library /starboard/common/.

Log synchronization responsibility has been moved behind Starboard.

The application is no longer responsible for synchronizing (e.g. via mutex) calls to Starboard logging, this is now expected to be done by the Starboard implementation. Logging functions, such as SbLog or SbLogRaw, must now have implementations that are thread-safe because they will be called from multiple threads without external synchronization.

Additionally, the minimum logging level is no longer set by the application, and is instead set by grabbing the value as a command-line argument within Starboard.

Starboard now provides a EGL and GLES interface as a structure of pointers.

To remove the direct inclusion of EGL and GLES system libraries throughout the application, we need to move this dependency behind a Starboardized API. This API can be found in /starboard/egl.h and /starboard/gles.h.

Add interface for querying for CPU features, in /starboard/cpu_features.h.

The new interface enables the platform to communicate to the application which CPU features are available, which can enable the application to perform certain CPU-specific optimizations (e.g. SIMD).



These macros must always be set to 1 for Starboard version 6 or later. They will be removed in a future version. Any implementation that supports Starboard version 6 or later should be modified to no longer depend on these macros, with the assumption that their values are always 1.

Version 10

Introduce functions to query at runtime for media buffer settings

In particular, the following methods are introduced:

  • SbMediaGetAudioBufferBudget
  • SbMediaGetBufferAlignment
  • SbMediaGetBufferAllocationUnit
  • SbMediaGetBufferGarbageCollectionDurationThreshold
  • SbMediaGetBufferPadding
  • SbMediaGetBufferStorageType
  • SbMediaGetInitialBufferCapacity
  • SbMediaGetMaxBufferCapacity
  • SbMediaGetProgressiveBufferBudget
  • SbMediaGetVideoBufferBudget
  • SbMediaIsBufferPoolAllocateOnDemand
  • SbMediaIsBufferUsingMemoryPool

Add support for player_filter_tests

Require compiling ‘player_filter_tests’ test target sources on all platforms, including and For this Starboard API version and beyond, SB_HAS(PLAYER_FILTER_TESTS) is true.

Deprecate SbMediaTime for SbTime

SbMediaTime, which is 90khz based, was used to represent timestamps and duration related to SbPlayer. As most of the platforms represent video related times in milliseconds or microseconds, this causes a lot of otherwise unnecessary conversion. Now all timestamps and duration related to SbPlayer are represented by SbTime directly.

Refine sample writing of SbPlayer

Added two new functions SbPlayerGetMaximumNumberOfSamplesPerWrite() and SbPlayerWriteSample2(). The former allows implementation to specify the maximum numbers of samples that can be written using the latter at once. As it takes multiple thread context switches to call SbPlayerWriteSample2() once, it can optimize performance on low end platforms by reducing the frequence of calling SbPlayerWriteSample2().

Add support for player error messages

SbPlayerCreate() now accepts an additional parameter, player_error_func, that can be called when an error occurs to propagate the error to the application.

Add support for system-level closed caption settings

SbAccessibilityGetCaptionSettings() and SbAccessibilitySetCaptionsEnabled() along with a number of supporting structure definitions have been added to accessibility.h. Platforms will need to define SB_HAS_CAPTIONS to 1 in order to enable the interface.

Add support for audioless video playback

SbPlayer can be created with only a video track, without any accompanying audio track. The SbPlayer implementation must now be able to play back a sole video track.

Add support for audio only video playback

SbPlayer can be created with only an audio track, without any accompanying video track. The SbPlayer implementation must now be able to play back a sole audio track.

Require support for creating multiple SbPlayer instances

Formerly, there were no tests ensuring that calling SbPlayerCreate() multiple times (without calling SbPlayerDestroy() in between) would not crash, and likewise no tests ensuring that calling SbAudioSinkCreate() multiple times (without calling SbAudioSinkDestroy() in between) would not crash. SbPlayerCreate() may return kSbPlayerInvalid if additional players are not supported. SbAudioSinkCreate() may return kSbAudionSinkInvalid if additional audio sinks are not supported.

Require stricter error handling on calls some SbPlayer* calls

Specifically, SbPlayerCreate(), SbPlayerCreateWithUrl() and SbDrmCreateSystem() must result in invalid return values (e.g. kSbPlayerInvalid or kSbDrmSystemInvalid appropriately).

Refine the DRM API

Specifically, the following changes have been made:

  1. Add a callback to SbDrmCreateSystem that allows a DRM system to signal that a DRM session has closed from the Starboard layer. Previously, DRM sessions could only be closed from the application layer.
  2. Allow calling SbDrmSessionUpdateRequestFunc and SbDrmSessionUpdatedFunc with extra status and optional error message.
  3. Add request type parameter to SbDrmSessionUpdateRequestFunc to support individualization, license renewal, and license release.

Remove kSbSystemPathSourceDirectory

Test code looking for its static input files should instead use the test subdirectory in kSbSystemPathContentDirectory.

Remove kSbSystemPropertyPlatformUuid

This property was only ever used in platforms using in_app_dial. The only usage of this system property was replaced with a self-contained mechanism.

Deprecate kSbMediaAudioSampleTypeInt16

SB_HAS_QUIRK_SUPPORT_INT16_AUDIO_SAMPLES has to be defined to continue support int16 audio samples after this version.

Add kSbPlayerErrorCapabilityChanged to SbPlayerError

This allows the SbPlayer implementation to notify the app that its playback capability has changed during a video playback. For example, the system may support vp9 decoding with an external GPU. When the external GPU is detached, this error code can signal the app to retry the playback, possibly with h264.

Add support for SbSystemSupportsResume()

Platforms doesn't need to resume after suspend can return false in SbSystemSupportsResume() to free up the resource used by resume after suspend. Please see the comment in system.h for more details.

Support the kSbKeyMicrophone keycode

Add support for new decode target type, kSbDecodeTargetFormat3Plane10BitYUVI420

Added kSbDecodeTargetFormat3Plane10BitYUVI420 to the SbDecodeTargetFormat enum in order to support 10-bit YUV textures.

Optionally provide absolute timestamp to SbAudioSinkConsumeFramesFunc()

SbAudioSinkConsumeFramesFunc() can now optionally accept an absolute timestamp parameter that indicates when the frames are consumed. Platforms that have the frames_consumed updated asynchronously can have more accurate audio time reporting with this extra parameter. Please see the comment in audio_sink.h for more details.

Add support for the SbAtomic8 type and memory access functions

Introduce SbMemoryProtect()

SbMemoryProtect() allows memory access permissions to be changed after they have been mapped with SbMemoryMap.

Add a timestamp field to SbInputData

This allows platforms to provide more precise information on exactly when an input event was generated. Note that if SbSystemHasCapability(kSbSystemCapabilitySetsInputTimestamp) returns false, the timestamp field of SbInputData should be ignored by applications.

Introduces kSbMemoryMapProtectReserved flag.

kSbMemoryMapProtectReserved, which is identical to SbMemoryMapFlags(0), is introduced. When SbMemoryMap() is called with kSbMemoryMapProtectReserved, only virtual address space should be reserved for the mapped memory, and not actual physical memory.

Add support for multiple versions of ffmpeg

An extra version agnostic ffmpeg dynamic dispatch layer is added in order to support multiple different versions of ffmpeg as may appear on user systems.

Make linux-x64x11 builds use GLX (via Angle) instead of EGL by default

While common Cobalt code still targets EGL/GLES2, we now use Angle on linux-x64x11 builds to translate those calls to GLX/GL calls. Thus, from the perspective of the system, linux-x64x11 builds now appear to use GLX/GL. This change was made because GLX/GL was generally found to have better desktop support than EGL/GLES2. The logic for this is added in the Starboard enable_glx_via_angle.gypi file.

Split base.gypi into cobalt_configuration.gypi and base_configuration.gypi

Up until now, both Cobalt-specific build configuration options as well as application-independent Starboard build configuration options were mixed together within base.gypi. They have now been split apart, and the application independent options have been moved into Starboard under base_configuration.gypi. The Cobalt-specific options have been left in Cobalt, though renamed to cobalt_configuration.gypi.

Moved tizen to contrib/tizen.

Please see contrib/ for description of expectations for contents in this directory.

Version 9

Add string label to SbMicrophoneInfo.

This should indicate the friendly name of the microphone type.

Introduce additional SbSocketError enum values.

Instead of the single generic kSbSocketErrorFailed to indicate socket errors, the enum kSbSocketErrorConnectionReset has been introduced corresponding to various dropped TCP connection errors. This is particularly useful in identifying socket errors that can be retried.

Add new keycode kSbKeyInstantReplay


Version 8

Add SbPlayerCreateWithUrl(), SbPlayerSetDrmSystem(), SbPlayerOutputModeSupportedWithUrl()

For platform media players that rely on using a URL (like an m3u playlist URL) for playback, add SbPlayerCreateWithUrl() which takes in a URL, no video or audio configs, and no DRM system. Allow the DRM system to be set on a running SbPlayer exactly once for SbPlayers created with a URL. Also, since URL players will not expose codec information, use a custom SbPlayerOutputModeSupportedWithUrl() to query player output mode support.

Add kSbEventTypeWindowSizeChanged

An event indicating that an SbWindow's size has changed. The event data is SbEventWindowSizeChangedData, containing a SbWindow and SbWindowSize.

Add SbWindowShowOnScreenKeyboard(), SbWindowHideOnScreenKeyboard(), SbWindowFocusOnScreenKeyboard(), SbWindowBlurOnScreenKeyboard(), SbWindowIsOnScreenKeyboardShown(), SbWindowSetOnScreenKeyboardKeepFocus()

These methods show, hide, focus, and blur a native on screen keyboard, determine if the on screen keyboard is shown, and set whether focus is kept to the on screen keyboard. The on screen keyboard also handles kSbInputEventTypeInput, which use a new field input_text of SbInputData.

Version 7

SbDecodeTargetInfoPlane can specify color plane information

Previously: Planes of type kSbDecodeTargetFormat2PlaneYUVNV12 were assumed to have the luma mapped to the alpha channel (GL_ALPHA) and the chroma mapped to blue and alpha (GL_LUMINANCE_ALPHA). However, some graphics systems require that luma is on GL_RED_EXT and the chroma is on GL_RG_EXT.

Version 6

Named SbStorageRecords

This extends the SbStorage interface with the ability to open named SbStorageRecords. Calling SbStorageOpenRecord and SbStorageDeleteRecord with a NULL name parameter provides access to the old “default” record.

Introduce pointer (mouse) input support

This extends the SbInput interface with some enum values and data members to allow mouse, wheel, and more generic pointer input.

Flexible audio specific config

SbMediaAudioHeader::audio_specific_config will be a pointer instead of an array.

Time Zone API Cleanup

Removes SbTimeZoneGetDstName() -- The Daylight Savings Time version of the time zone.

Changes SbTimeZoneGetName() to be more flexible in what it is allowed to return.


Adds the convenience inline function, SbDecodeTargetNumberOfPlanesForFormat() to starboard/decode_target.h.

Preload Support

Adds the kSbEventTypePreload event, and modifies the application state machine to utilize it.

Platform Error Cleanup

Removes SbSystemPlatformErrorType values specific to user status.

SbDecodeTarget support for the UYVY (i.e. YUV 422) format

Add support for UYVY decode targets (e.g. YUV 422) via the kSbDecodeTargetFormat1PlaneUYVY enum.

Add More Remote Keys

This adds SbKey codes for:

  • Color keys
  • Closed Caption key
  • Application launch key
  • Channel Up/Down keys
  • Info key
  • Guide key
  • Last/Previous Channel key
  • Media audio track select key


Adds a new event type -- kSbEventTypeLowMemory -- to allow a platform to signal that the application may soon be terminated due to low memory availability.

Interface change to SbPlayerWriteSample()

const is added to sample_buffers and sample_buffer_sizes parameters.

Support key status change

Add key_statuses_changed_callback parameter to SbDrmCreateSystem() to support MediaKeySession::keyStatuses and MediaKeySession::onkeystatuseschange.

Changes thumbstick direction

Change the meaning of negative values for thumbstick position from bottom right to upper left.

Version 5

Add Speech Recognizer API

Introduce starboard/speech_recognizer.h. This newly-introduced starboard/speech_recognizer.h adds the on-device speech recognizer feature.

Added new system property to allow platform-specific user agent suffixes

Adds kSbSystemPropertyUserAgentAuxField to the SbSystemPropertyId enum to allow platform-specific User-Agent suffix.

Remove unused enums from starboard/input.h

The following unused enum values are removed from starboard/input.h:

  • kSbInputDeviceTypeMicrophone
  • kSbInputDeviceTypeSpeechCommand
  • kSbInputEventTypeAudio
  • kSbInputEventTypeCommand
  • kSbInputEventTypeGrab
  • kSbInputEventTypeUngrab

Version 4

Decode-to-Texture Player Output Mode

Feature introducing support for decode-to-texture player output mode, and runtime player output mode selection and detection. In starboard/configuration.h,

  • SB_IS_PLAYER_PUNCHED_OUT, SB_IS_PLAYER_PRODUCING_TEXTURE, and SB_IS_PLAYER_COMPOSITED now no longer need to be defined (and should not be defined) by platforms. Instead, these capabilities are detected at runtime via SbPlayerOutputModeSupported().

In starboard/player.h,

  • The enum SbPlayerOutputMode is introduced.
  • SbPlayerOutputModeSupported() is introduced to let applications query for player output mode support.
  • SbPlayerCreate() now takes an additional parameter that specifies the desired output mode.
  • The punch out specific function SbPlayerSetBounds() must now be defined on all platforms, even if they don't support punch out (in which case they can implement a stub).
  • The function SbPlayerGetCompositionHandle() is removed.
  • The function SbPlayerGetTextureId() is replaced by the new SbPlayerGetCurrentFrame(), which returns a SbDecodeTarget.

In starboard/decode_target.h,

  • All get methods (SbDecodeTargetGetPlane() and SbDecodeTargetGetFormat(), SbDecodeTargetIsOpaque()) are now replaced with SbDecodeTargetGetInfo().
  • The SbDecodeTargetInfo structure is introduced and is the return value type of SbDecodeTargetGetInfo().
  • SbDecdodeTargetCreate() is now responsible for creating all its internal planes, and so its planes parameter is replaced by width and height parameters.
  • The GLES2 version of SbDecdodeTargetCreate() has its EGL types (EGLDisplay, EGLContext) replaced by void* types, so that decode_target.h can avoid #including EGL/GLES2 headers.
  • SbDecodeTargetDestroy() is renamed to SbDecodeTargetRelease().

In starboard/player.h, starboard/image.h and starboard/decode_target.h,

  • Replace SbDecodeTargetProvider with SbDecodeTargetGraphicsContextProvider.
  • Instead of restricting Starboard implementations to only be able to run SbDecodeTarget creation and destruction code on the application‘s renderer’s thread with the application‘s renderer’s EGLContext current, Starboard implementations can now run arbitrary code on the application‘s renderer’s thread with its EGLContext current.
  • Remove SbDecodeTargetCreate(), SbDecodeTarget creation is now an implementation detail to be dealt with in other Starboard API functions that create SbDecodeTargets, like SbImageDecode() or SbPlayerCreate().

Playback Rate

Support for setting the playback rate on an SbPlayer. This allows for control of the playback speed of video at runtime.

Floating Point Input Vector

Change input.h's SbInputVector structure to contain float members instead of ints.

Delete SbUserApplicationTokenResults

Deleted the vestigal struct SbUserApplicationTokenResults from user.h.

Storage Options for Encoded Audio/Video Data

Enables the SbPlayer implementation to provide instructions to its user on how to store audio/video data. Encoded audio/video data is cached once being demuxed and may occupy a significant amount of memory. Enabling this feature allows the SbPlayer implementation to have better control on where encoded audio/video data is stored.

Unified implementation of SbMediaCanPlayMimeAndKeySystem()

Use a unified implementation of SbMediaCanPlayMimeAndKeySystem() based on SbMediaIsSupported(), SbMediaIsAudioSupported(), and SbMediaIsVideoSupported().

Introduce ticket parameter to SbDrmGenerateSessionUpdateRequest()

Introduce ticket parameter to SbDrmGenerateSessionUpdateRequest() and SbDrmSessionUpdateRequestFunc to allow distinguishing between callbacks from multiple concurrent calls.

Introduce SbSocketGetInterfaceAddress()

SbSocketGetInterfaceAddress() is introduced to let applications find out which source IP address and the associated netmask will be used to connect to the destination. This is very important for multi-homed devices, and for certain conditions in IPv6.

Introduce starboard/cryptography.h

In newly-introduced starboard/cryptography.h,

  • Optional support for accelerated cryptography, which can, in particular, be used for accelerating SSL.

Introduce z-index parameter to SbPlayerSetBounds()

Allow SbPlayerSetBounds to use an extra parameter to indicate the z-index of the video so multiple overlapping videos can be rendered.

Media source buffer settings removed from configuration.h

Media source buffer settings in Starboard.

Introduce starboard/accessibility.h

In particular, the functions SbAccessibilityGetDisplaySettings() and SbAccessibilityGetTextToSpeechSettings() have now been introduced.

Additionally, a new Starboard event, kSbEventTypeAccessiblitySettingsChanged, has been defined in starboard/event.h.

HDR decode support

In starboard/media.h, SbMediaColorMetadata is now defined and it contains HDR metadata. The field SbMediaColorMetadata color_metadata is now added to SbMediaVideoSampleInfo.

Add kSbSystemDeviceTypeAndroidTV to starboard/system.h

A new device type, kSbSystemDeviceTypeAndroidTV, is added to starboard/system.h.

Deprecate SbSpeechSynthesisSetLanguage()

SbSpeechSynthesisSetLanguage() has been deprecated.

Request State Change Support

Added SbSystemRequestPause(), SbSystemRequestUnpause(), SbSystemRequestSuspend().

SbSystemRequestSuspend() in particular can be hooked into a platform's “hide” or “minimize” window functionality.

Font Directory Path Support

Added kSbSystemPathFontDirectory and kSbSystemPathFontConfigurationDirectory which can be optionally specified for platforms that want to provide system fonts to Starboard applications. The font and font configuration formats supported are application-specific.

Add SB_NORETURN to starboard/configuration.h.

Added attribute macro SB_NORETURN to allow functions to be marked as noreturn.

Mark SbSystemBreakIntoDebugger SB_NORETURN.

Add SB_NORETURN to declaration of SbSystemBreakIntoDebugger, to allow it to be used in a manner similar to abort.

Introduce SbAudioSinkGetMinBufferSizeInFrames()

Introduce SbAudioSinkGetMinBufferSizeInFrames() to starboard/audio_sink.h which communicates to the platform how many audio frames are required to ensure that audio sink can keep playing without underflow.