Flutter Audio-Video Practice and Optimization in Kuaishou

This article details Kuaishou's Flutter audio-video implementation, optimization practices, and engineering support. The team chose pure Flutter development for complex video editing features to achieve cross-platform consistency and development efficiency. Key technical challenges included video playback implementation, complex UI/state management, efficient data communication, and performance optimization.

For video playback, the article explains the external texture approach where Flutter creates a Texture ID, binds it to a Texture Widget, and receives native video stream data via shared memory mechanisms (Surface Texture on Android, Flutter Texture on iOS). This allows native video rendering to be displayed within Flutter's rendering pipeline.

Data communication was optimized by moving all business logic to Flutter, assembling VideoEditorProject in Dart, and using Protocol Buffers for consistent model serialization across Android, iOS, and Flutter. This eliminated the need for native business logic development and improved development efficiency by approximately 50% compared to native development.

Performance optimization included FFI integration for direct Dart-to-C++ communication with audio-video SDKs, thumbnail retrieval optimization using shared texture schemes, and frame rate improvements through UI thread optimization techniques like avoiding expensive operations in build methods, controlling refresh ranges, and using const widgets. The team also developed KDebugTools, an open-source Flutter debugging toolkit with features like network interception, widget inspection, and device file management.

The article concludes that Flutter is suitable for medium-sized new projects where rapid iteration is prioritized over native-level performance, and that Flutter 2's stability makes it increasingly viable for cross-platform development.