Google today launched the second and final Android 8.1 Oreo developer preview (the first preview arrived in October). Developer Preview 2 is available for Pixel 2, Pixel 2 XL, Pixel, Pixel XL, Pixel C, Nexus 5X, Nexus 6P, and the Android emulator.
You can get the preview update over-the-air on your Pixel or Nexus device by enrolling in the Android Beta Program.
Android 8.1 features Android Go optimizations, a new Neural Networks API, and a few smaller enhancements in response to feedback. Google is still aiming to release a final public version in December.
Today’s preview update includes near-final Android 8.1 system images for Pixel and Nexus devices, as well as the official APIs (API level 27), the latest optimizations and bug fixes, and the November 2017 security patch updates.
The images are meant to be used for compatibility testing or to develop using Android 8.1’s new features:
- Android Go memory optimizations and targeting — A set of memory optimizations for Android Go configurations (1GB or less of memory). New hardware feature constants can target the distribution of apps and APK splits to normal or low-RAM devices running Android 8.1 and later.
- Neural Networks API — Neural Networks API in the NDK enables hardware-accelerated inference operations on supported devices. The Neural Networks API is a foundational layer for ML frameworks like TensorFlow Lite as well as Caffe2 and others.
- Autofill enhancements — Password managers and other Autofill services can now use the Autofill framework.
- Shared memory API — Apps can map anonymous shared memory and manage protection controls using the SharedMemory API. The API is parcelable, AIDL friendly, and exposes useful features like removing write permissions.
The Neural Networks
The Neural Networks API is arguably the biggest addition. Earlier this month, Google launched TensorFlow Lite (see GitHub for downloads and docs), its cross-platform ML library for mobile. TensorFlow Lite works with the Neural Networks API to run models like MobileNets, Inception v3, and Smart Reply efficiently on your mobile device.
On the Pixel 2 and Pixel 2 XL, the Android 8.1 update allows developers to tap into Pixel Visual Core, Google’s first custom-designed co-processor for image processing and ML. Once enabled, apps using Android Camera API can capture HDR+ shots through Pixel Visual Core.
The Android 8.1 APIs were made final last month, when Google opened Google Play for apps compiled against or targeting API level 27. Google is encouraging developers to publish APK updates in their alpha, beta, or production channels. If you’re a developer and want more information, check out the Android 8.1 for Developers site, the diff report, and the updated API reference docs.