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feat(android): on-device webcam capture via Camera2 (AndroidCameraEngine)

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Add on-device webcam capture to the experimental Android-TV build. Desktop
captures webcams via OpenCV (no Chaquopy/Android wheel); this adds a push-based
AndroidCameraEngine that plugs into the same selection path desktop uses
(capture template engine_type="android_camera" + display_index, HAS_OWN_DISPLAYS).

A Kotlin CameraBridge (Camera2) enumerates cameras and opens them on demand —
only while a capture source is active, driven Python->Kotlin via a guarded jclass
singleton (BleBridge pattern) — converts each frame YUV_420_888->RGB, and pushes
RGB bytes into a module-level queue mirroring mediaprojection_engine.py. Cameras
surface as selectable displays like the desktop OpenCV engine; the data-driven
capture-template UI is unchanged. No new Python deps; no new Gradle deps
(Camera2 is in-platform).

Engine: ENGINE_PRIORITY=0 (never auto-selected over MediaProjection=100; explicit
engine_type only). Single-camera ownership is serialized with a lock + ref-count
(same-camera streams attach, different-camera refused, last release stops),
mirroring the desktop CameraEngine guard.

Permission: CAMERA requested at capture-start, gated on FEATURE_CAMERA_ANY so
camera-less TV boxes never prompt; graceful degradation when denied. The service
is promoted with the camera FGS type (+ FOREGROUND_SERVICE_CAMERA) only when
CAMERA is already granted, so backgrounded capture keeps working without risking
a failed startForeground on camera-less boxes (camera can't ride the
MediaProjection token the way audio playback capture does).

Reviewed via multi-agent adversarial pass (13 findings -> 4 fixed: device leak on
session-failure, multi-stream collision, camera FGS type, i18n key; 9 refuted).

Tests: 18 new desktop-CI tests (no device needed); full suite 1883 passed.
Verified: assembleDebug BUILD SUCCESSFUL, ruff clean.

Docs: ANDROID-REVIEW/android-webcam-capture-plan.md (design), updated
android-missing-functionality.md + README feature table + en/ru/zh locales.
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2026-06-02 13:36:23 +03:00
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@@ -108,7 +108,7 @@ LedGrab runs as a desktop / server application:
| Feature | Windows | Linux / macOS | Android TV (experimental) |
| ------- | ------- | ------------- | ------------------------- |
| Screen capture | DXCam, BetterCam, WGC, MSS | MSS | MediaProjection; root `screenrecord` (rooted devices) |
| Webcam capture | OpenCV (DirectShow) | OpenCV (V4L2) | — (no OpenCV wheel) |
| Webcam capture | OpenCV (DirectShow) | OpenCV (V4L2) | Camera2 (on-demand, while capture is running) |
| Audio capture | WASAPI, Sounddevice | Sounddevice (PulseAudio/PipeWire) | AudioPlaybackCapture (API 29+) |
| GPU monitoring | NVIDIA (nvidia-ml-py) | NVIDIA (nvidia-ml-py) | — (CPU/RAM/battery/thermal via `/proc`) |
| Capture from Android phone | scrcpy (ADB) | scrcpy (ADB) | — (captures its own screen instead) |