Android 12: First Developer Preview Released

Approximately one year following the initial developer preview of Android 11, Google has unveiled the first developer preview of Android 12. While the Android 11 rollout experienced some delays due to pandemic-related adjustments, the development of Android 12 appears to remain on schedule.

Early Changes and Features

As is typical with an early developer preview, the majority of modifications are focused on the underlying system. Currently, there isn’t an over-the-air update available for non-developers eager to test the new features.

Key highlights of this release include the ability to transcode media into superior formats, such as the AV1 image format. Furthermore, notifications are now faster and more responsive. A new developer feature allows for toggling individual platform changes, simplifying app compatibility testing.

Google also intends to implement a Platform Stability milestone, mirroring the approach taken with Android 11. This will provide developers with advance notification regarding final app-facing changes within the operating system’s development cycle. The previous milestone was achieved in July with the release of the second beta.

Enhancements for Developers and Users

According to Google VP of Engineering Dave Burke, each iteration aims to create a smarter, more user-friendly, and higher-performing OS, prioritizing privacy and security. Android 12 introduces new tools for developers to build exceptional user experiences.

These tools encompass compatible media transcoding, enabling apps to work with the latest video formats even without native support, and streamlined copying and pasting of rich content – including images and videos – into applications. Additional privacy protections, UI refinements, and performance optimizations are also included to maintain app responsiveness.

Developer-Focused Updates in Detail

Numerous developer-specific updates are present in Android 12. Let's examine some of these in greater detail.

For the WebView component in Android 12, Google will now enforce the same SameSite cookie policies as Chrome. A previous slowdown in implementing this change, designed to hinder cross-site tracking by advertisers, was due to compatibility issues. With full implementation in Chrome, the Android team is confident in extending these privacy measures to WebView, which is utilized by other apps to display web content.

Regarding encoding capabilities, Burke explains that the increasing prevalence of HEVC hardware encoders in mobile devices leads to camera apps capturing footage in HEVC format, offering improved quality and compression. While most apps support HEVC, Android 12 provides a service for transcoding files into AVC for those that do not.

Android 12 also introduces support for the AV1 Image File Format as a container for images and GIF-like sequences. Burke clarifies that AVIF leverages intra-frame encoded content from video compression, resulting in significantly improved image quality for the same file size compared to older formats like JPEG.

Notification System Improvements

Google continues to refine the notification system with each Android release. This iteration promises a refreshed design to enhance modernity, usability, and functionality. Optimized transitions, animations, and the ability for apps to customize notifications with unique content are included.

Developers are now encouraged to implement a system that directly launches users into the app from a notification, bypassing intermediary broadcast receivers or services – a practice previously recommended.

Audio and System Optimizations

Android 12 offers enhanced support for multi-channel audio, accommodating up to 24 channels. This benefits music and audio applications. Spatial audio, MPEG-H support, and haptic-coupled audio effects, where vibration strength and frequency are synchronized with audio, are also included, enhancing gaming experiences.

Improvements to gesture navigation and numerous other optimizations and minor changes are also integrated throughout the operating system.

Project Mainline Advancements

Google is furthering its Project Mainline initiative, enabling an increasing number of core Android OS features to be updated via the Google Play system, circumventing the often-slow update cycles of hardware manufacturers. With Android 12, the Android Runtime module is integrated into Mainline.

This allows Google to push updates to the core runtime and libraries without requiring a full system update. Burke states this will improve runtime performance, memory management, and Kotlin operation speed. The seamless transcoding feature is also delivered within an updatable module.

A comprehensive list of all changes in Android 12 can be found here.

Availability and Supported Devices

Developers can begin testing their apps with Android 12 today by flashing a device image onto a Pixel device. Currently, Android 12 supports the Pixel 3/3 XL, Pixel 3a/3a XL, Pixel 4/4 XL, Pixel 4a/4a 5G, and Pixel 5. The system image is also available within the Android Emulator in Google’s Android Studio.