# Virtual Camera HAL — KernelSU Module

Replaces physical cameras on Pixel 9A (Android 16) with virtual cameras
backed by v4l2loopback, fed via RTSP stream or MP4 file.

## Architecture

```
Boot → post-fs-data.sh → insmod v4l2loopback.ko → /dev/video0
                        → copy binary + AIDL .so files → /data/local/tmp/
                        → start virtual_camera_provider with LD_LIBRARY_PATH
                          → registers ICameraProvider/virtual/0
                            → cameraserver discovers 2 virtual cameras
```

## Files

| Path | Purpose |
|------|---------|
| `module.prop` | KernelSU metadata |
| `post-fs-data.sh` | Boot startup (insmod, copy, start) |
| `service.sh` | Watchdog (30s delay) |
| `sepolicy.rule` | SELinux permissions |
| `v4l2loopback.ko` | Kernel module (0x440 struct, ARM64) |
| `vendor/bin/virtual_camera_provider` | AOSP-built AIDL HAL3 binary |
| `vendor/lib64/*.so` | AIDL NDK shared libraries (V3) |
| `system/etc/vintf/manifest/*.xml` | VINTF manifest overlay |
| `vendor/etc/vintf/manifest/*.xml` | VINTF manifest overlay (vendor) |
| `control.sh` | WebUI backend |
| `rtsp_feeder.sh` | RTSP/MP4 → /dev/video0 bridge |
| `webui/` | KSU WebUI (index.html, style.css, script.js) |

## Usage

1. Install module via KernelSU app or `ksud module install`
2. Reboot
3. Open KernelSU → Modules → Virtual Camera → WebUI
4. Configure RTSP URL or MP4 file path
5. Tap "Start" (provides 2 virtual cameras at IDs 10 and 11)

## Verification

```bash
# Check provider registered
adb shell su -c 'service list | grep camera.provider'
# Expected: ICameraProvider/virtual/0

# Check virtual cameras
adb shell su -c 'dumpsys media.camera | grep "Number of camera"'
# Expected: Number of camera devices: 4

# Check camera characteristics
adb shell su -c 'dumpsys media.camera | grep -A25 "virtual/10"'
```

## Building

```bash
cd /mnt/opslag/aosp-16-platform
export TARGET_RELEASE=bp2a
source build/envsetup.sh
lunch aosp_arm64-bp2a-userdebug
cd external/virtualcam && mma -j10
```

## Key Fixes

- **-3 registration error**: Overrode `createBinder()` to skip 
  `AIBinder_markVintfStability` which caused STATUS_BAD_VALUE
- **CANNOT LINK**: Bundled AIDL V3 .so files with module
- **AOSP build memory**: Use `-j10` for 10 cores max, incremental builds 
  are fast after initial Soong analysis