[Jul 1st 2024] Cobalt 25.LTS.1 Release Candidate

Cobalt 25.lts.1 Release

The Cobalt team is thrilled to announce the RC (Release Candidate) of Cobalt 25 LTS 1 !

Evergreen binaries are available on GitHub (5.1.2)

Cobalt 25 LTS includes Starboard API version 16 for porters and its Stable release version will support all features that are required for 2025 YouTube Certification. The code is available at Cobalt open source 25.lts.1+ branch. Read branching / versioning documents for more information.

There are newly implemented features, improvements, and simplified code. We have outlined the changelist below with a brief description of Cobalt 25 LTS and Starboard 16 changes.

IMPORTANT NOTE: As this version is a RC (Release Candidate), the code is subject to change while we expect to have no more Starboard API changes. This is ready for integration and we STRONGLY RECOMMEND you start integration of this Cobalt 25 LTS RC on your respective platforms early and report issues ASAP so there is ample time to investigate and resolve any detected issues before Cobalt 25 LTS Stable Release later this year.

The Evergreen static version channels command (co 25lts1) can be used to update builds to the 25.LTS.1 Cobalt version for testing by following the steps provided here.

Cobalt Changes

Full change log for more information.

New Features / Support

  • Chromium M114 Update: Upgraded most Chromium components to align with the M114 milestone release - including syncing the build environment and compilers.

  • HTTP/3 with IETF QUIC: Integrated HTTP/3 with IETF standard QUIC for enhance video playback performance in challenging network conditions.

  • Immersive Audio Model and Formats (IAMF): Added support for IAMF audio.

  • Android S Support: Extended compatibility to Android S.

Updates / Improvements

  • Embedded ICU Data: Linked ICU data directly into the Cobalt binary, reducing storage (via binary compression) and simplifying updates.

  • Logging and Telemetry Enhancements: Improved logging and telemetry for update reliability and crash reporting.

Evergreen

  • LZ4 Compressed Binaries: Made LZ4 compressed binaries the default distribution format.

  • Evergreen-Full on AOSP: Enabled Evergreen-Full support on AOSP (Android Open Source).

Starboard changes

Full change log for more information.

New Features / Support

  • POSIX API Adoption: Adopted POSIX APIs (see migration guide for details), reducing the total number of Starboard interface functions to 191 (vs 274 in Starboard 15).

  • Partial Audio Frame Support: Introduced a new configuration constant (kHasPartialAudioFramesSupport) for partial audio frames.

Updates / Improvements

  • pthread Migration: Migrated various components (e g., SbConditionVariable, SbOnce, SbThreadLocalKey, etc…) to pthread.

  • Memory and File System Migration: Migrated memory allocation functions (SbMemoryAllocate, SbMemoryMap etc…) to malloc, mmap and file system functions (SbDirectoryOpen or SbDirectoryClose for example) to equivalent opendir, closedir, etc..

  • Socket API Migration: Migrated SbSocket to socket APIs.

  • Starboard Extensions : Accessibility and OnScreenKeyboard Starboard APIs are converted to Starboard Extensions (available in starboard/extension/accessibility.h and starboard/extension on_screen_keyboard.h respectively).

  • Build Standard Upgrade: Upgraded the C build standard to C11.

    • Removed SB_C_NOINLINE.

    • Deprecated SB_C_INLINE and removed config for SB_C_FORCE_INLINE.

    • Removed configs for SB_EXPORT_PLATFORM and SB_IMPORT_PLATFORM.

  • Configuration Changes:

    • Changed MAP_EXECUTABLE_MEMORY from build-time to runtime config (kSbCanMapExecutableMemory).

  • Additional Migrations: Migrated SbDirectoryCanOpen, SbFileExists, and SbFileGetPathInfo to stat , and SbFileOpen, SbFileClose to open, close.

Deprecations

  • Deprecated Evergreen-x86 ABI: The x86 platform configurations, builds and ABI are no longer supported for Evergreen.

  • OnScreenKeyboard: Deprecated OnScreenKeyboard.

  • Unused Configurations: Deprecated various unused configurations (e.g., SB_HAS_GLES2, SB_HAS_NV12_TEXTURE_SUPPORT, VIRTUAL_REALITY, DeployPathPatterns, SPEECH_SYNTHESIS, FILESYSTEM_ZERO_FILEINFO_TIME, SB_HAS_PIPE).

  • Audio and Media:

    • Deprecated SB_HAS_QU (SUPPORT_INT16_AUDIO_SAMPLES).

    • Deprecated SbMediaGetBufferAlignment, SbMediaGetBufferPadding, and SbMediaGetBufferStorageType.

    • Deprecated SbMediaIsBufferUsingMemoryPool, memory pool is always used (SbMediaIsBufferUsingMemoryPool is required to be true).

  • Starboard Hash Configs: Deprecated Starboard hash configs.

2025 YouTube Certification

Remember to use 25.lts.stable for the 2025 YouTube certification and for your product release. Cobalt Known Issues with Status, Fixes, and Mitigations can be found in the YouTube Partner Portal.

Contact Points

Please contact our support channels if you have any problems, questions, or feedback.

Thank you,
On behalf of the Cobalt team