frankbarretta/lsfg-android-application

Purpose and Entry Points

LSFG is a sideloaded Android frame-generation overlay for games. It captures display frames, runs a patched external lsfg-vk-android framegen library, and presents generated frames above the target app. Main UI/navigation begins at app/src/main/java/com/lsfg/android/ui/MainActivity.kt; runtime orchestration is the foreground service in app/src/main/java/com/lsfg/android/session/LsfgForegroundService.kt.

UI, Configuration, and Session Launch

Compose screens collect DLL, target-app, projection, pacing, and framegen settings, persisted through preferences. A projection request yields the per-session MediaProjection token; the service must post its foreground notification before capture work. Relevant paths: app/src/main/java/com/lsfg/android/ui/ProjectionRequestActivity.kt, app/src/main/java/com/lsfg/android/prefs/LsfgPreferences.kt, app/src/main/java/com/lsfg/android/session/LsfgForegroundService.kt.

Overlay Host and Input Boundary

OverlayManager owns the system overlay and its surface lifecycle. It can use application-overlay windows or an accessibility-overlay host; the latter is mediated by the accessibility service. The service waits for a valid output surface before starting capture, and surface recreation drives resize/retarget handling. Touch passthrough is implemented through touchable-inset management rather than non-touchable window flags. Paths: app/src/main/java/com/lsfg/android/session/OverlayManager.kt, app/src/main/java/com/lsfg/android/session/LsfgAccessibilityService.kt, app/src/main/java/com/lsfg/android/session/FrameGraphView.kt.

Capture and Privileged Timing

The visible video path is MediaProjection → VirtualDisplay → ImageReader → AHardwareBuffer; CaptureEngine supplies these frames to JNI/native rendering. Root and Shizuku code provide alternative/privileged integration, but Shizuku is timing-only and does not supply visible overlay buffers. Its AIDL boundary separates the app from the Shizuku user service. Paths: app/src/main/java/com/lsfg/android/session/CaptureEngine.kt, app/src/main/java/com/lsfg/android/session/ShizukuCaptureEngine.kt, app/src/main/aidl/com/lsfg/android/shizuku/IShizukuCaptureService.aidl.

Native Render and Framegen Pipeline

Kotlin calls one JNI boundary; native code owns a worker-thread render loop, persistent Vulkan session, AHardwareBuffer import, framegen context lifecycle, pacing, and presentation to the overlay ANativeWindow. Imported buffers are shared with framegen through Android Vulkan external-memory/AHB mechanisms; device synchronization is a critical boundary because framegen has its own Vulkan device. Paths: app/src/main/java/com/lsfg/android/session/NativeBridge.kt, app/src/main/cpp/lsfg_jni.cpp, app/src/main/cpp/lsfg_render_loop.cpp, app/src/main/cpp/android_vk_session.cpp, app/src/main/cpp/ahb_image_bridge.cpp.

Shader Asset Pipeline and Capability Gate

A user-selected proprietary Lossless.dll is processed on-device: native extraction translates DXBC resources to SPIR-V, writes shader assets under app storage, then probes each module on a headless Vulkan device before full initialization. The DLL is deleted afterward. Devices lacking required Vulkan capabilities—especially robustness2—fall back to capture-only mirror output. Paths: app/src/main/java/com/lsfg/android/session/ShaderExtractor.kt, app/src/main/cpp/android_shader_loader.cpp, app/src/main/cpp/android_vk_probe.cpp.

Runtime Coordination and Infrastructure

Parameter changes requiring allocation/context changes are serialized by the foreground service; hot-applicable controls use dedicated JNI calls. Native crash handlers and Kotlin crash reporting preserve failures for next-launch reporting. The app targets Android 10+ and uses Kotlin/Compose plus C++20/NDK/CMake, Vulkan 1.2+, MediaProjection, WindowManager overlays, optional AccessibilityService, and optional Shizuku. Planned CPU/GPU/NNAPI postprocessing scaffolding exists but is not end-to-end wired. Paths: app/src/main/java/com/lsfg/android/session/CrashReporter.kt, app/src/main/cpp/crash_reporter.cpp, app/src/main/cpp/nnapi_postprocess.cpp.