lck-control/docs/hub-vs-control-comparison.md

# LIV Control Center (Hub) vs LCK Control (Companion App)

## Comprehensive Architecture Comparison & Unification Strategy

---

## 1. Executive Summary

LIV has two parallel applications for managing game streaming on Quest:

| | **Hub** (`liv-control-center`) | **Control** (`lck-control`) |
|---|---|---|
| **Stage** | Production (Quest Store, low reviews) | Prototype (new architecture) |
| **Stack** | Rust + Tauri + Leptos (WASM) | Kotlin + Jetpack Compose + Hilt |
| **Streaming** | App captures screen & encodes | Game encodes directly from render pipeline |
| **Communication** | Async via backend server | Synchronous IPC via AIDL |
| **Destinations** | Single target | Multi-destination |
| **UE5 Plugin** | `LCKStreaming` (HTTP/JSON-RPC) | `LCKControl` (AIDL/JNI) |

---

## 2. High-Level Architecture

### 2.1 Hub Architecture

```mermaid
graph TB
    subgraph Quest Headset
        subgraph "Hub App (Tauri + Leptos WASM)"
            UI_H["Leptos UI<br/>(WASM)"]
            Core_H["Rust Core<br/>(Tauri Backend)"]
            Encoder_H["MediaCodec<br/>H.264 + AAC"]
            RTMP_H["minirtmp<br/>(RTMP Client)"]
            Capture["ScreenCaptureService<br/>(MediaProjection)"]
        end
        subgraph "UE5 Game"
            Plugin_S["LCKStreaming Plugin"]
            API_Client["HTTP/JSON-RPC Client"]
        end
    end

    subgraph "Cloud Server"
        Backend_H["Hub Backend<br/>(api.obi.gg)"]
    end

    subgraph "Streaming Platforms"
        YT["YouTube Live"]
        TW["Twitch"]
    end

    UI_H <-->|Tauri IPC| Core_H
    Core_H -->|JSON-RPC 2.0<br/>HTTPS + Cert Pinning| Backend_H
    Plugin_S -->|JSON-RPC 2.0<br/>HTTPS| Backend_H
    Backend_H -->|"Device Pairing<br/>(async polling)"| Plugin_S
    Core_H --> Capture
    Capture --> Encoder_H
    Encoder_H --> RTMP_H
    RTMP_H -->|RTMP| YT
    RTMP_H -->|RTMP| TW

    style Backend_H fill:#f96,stroke:#333
    style Capture fill:#ff9,stroke:#333
    style Encoder_H fill:#ff9,stroke:#333
```

**Key: The Hub app captures the screen, encodes it, and streams. The game and hub communicate indirectly through the backend server.**

### 2.2 Control App Architecture

```mermaid
graph TB
    subgraph Quest Headset
        subgraph "Control App (Kotlin + Compose)"
            UI_C["Compose UI"]
            VM["ViewModels + Repos"]
            Service["LckControlService<br/>(Foreground + AIDL)"]
            DB["Room DB<br/>(Local Cache)"]
        end
        subgraph "UE5 Game"
            Plugin_C["LCKControl Plugin"]
            JNI["JNI Bridge"]
            SDK["lck-control-sdk<br/>(AAR)"]
            Encoder_C["LCK Encoder<br/>(H.264 + AAC)"]
            RTMP_C1["RTMP Sink 1"]
            RTMP_C2["RTMP Sink 2"]
            RTMP_CN["RTMP Sink N"]
        end
    end

    subgraph "Self-Hosted Server"
        Backend_C["Control Backend<br/>(Node.js + Fastify)"]
        SQLite["SQLite DB"]
    end

    subgraph "Streaming Platforms"
        YT2["YouTube Live"]
        TW2["Twitch"]
        Manual["Custom RTMP"]
    end

    UI_C <--> VM
    VM <-->|REST API<br/>JWT Auth| Backend_C
    VM <--> DB
    VM <--> Service

    Plugin_C --> JNI
    JNI --> SDK
    SDK <-->|"AIDL IPC<br/>(Bound Service)"| Service

    Backend_C <--> SQLite
    Backend_C -->|"OAuth + RTMP<br/>Resolution"| YT2
    Backend_C -->|"OAuth + RTMP<br/>Resolution"| TW2

    Encoder_C --> RTMP_C1
    Encoder_C --> RTMP_C2
    Encoder_C --> RTMP_CN
    RTMP_C1 -->|RTMP| YT2
    RTMP_C2 -->|RTMP| TW2
    RTMP_CN -->|RTMP| Manual

    style Service fill:#9f9,stroke:#333
    style SDK fill:#9f9,stroke:#333
    style Encoder_C fill:#9cf,stroke:#333
```

**Key: The game encodes directly from its render pipeline and streams to multiple destinations. The companion app provides stream configuration via direct IPC.**

---

## 3. Communication Model Comparison

### 3.1 Hub: Server-Mediated Async Communication

```mermaid
sequenceDiagram
    participant Game as UE5 Game<br/>(LCKStreaming)
    participant Server as Hub Backend<br/>(api.obi.gg)
    participant Hub as Hub App<br/>(Tauri)
    participant Platform as YouTube/Twitch

    Note over Game,Hub: Device Pairing (one-time)
    Game->>Server: create_device_login_attempt()
    Server-->>Game: 6-digit pairing code
    Game->>Game: Display code to user
    Hub->>Server: pair_device(code)
    Server-->>Hub: Device paired

    Note over Game,Hub: Stream Setup
    Hub->>Server: get_user_profile()
    Server-->>Hub: Streaming target + RTMP URL
    Hub->>Hub: Start screen capture
    Hub->>Hub: Encode H.264 + AAC
    Hub->>Platform: RTMP stream

    Note over Game,Server: Game has no direct<br/>connection to Hub
    Game->>Server: Poll for updates (2.5s)
    Server-->>Game: Current state
```

### 3.2 Control: Direct IPC Communication

```mermaid
sequenceDiagram
    participant Game as UE5 Game<br/>(LCKControl + JNI)
    participant App as Control App<br/>(AIDL Service)
    participant Server as Control Backend<br/>(Fastify)
    participant Platform as YouTube/Twitch

    Note over Game,App: Service Binding (direct)
    Game->>App: bindService() via AIDL
    App-->>Game: ILckControlService binder
    Game->>App: registerAsClient("MyGame", pkg)
    App-->>Game: clientId

    Note over Game,Platform: Stream Lifecycle
    Game->>App: getStreamPlans()
    App-->>Game: List<StreamPlan>
    Game->>App: prepareStreamPlan(planId)
    App->>Server: POST /streams/plans/{id}/prepare
    Server->>Platform: Create broadcast + get RTMP URLs
    Platform-->>Server: RTMP URLs + stream keys
    Server-->>App: PrepareResponse
    App-->>Game: StreamPlan (with RTMP data)

    Game->>Game: Encode from render pipeline
    Game->>Platform: RTMP stream (dest 1)
    Game->>Platform: RTMP stream (dest 2)

    Game->>App: startStreamPlan(planId)
    App->>Server: POST /streams/plans/{id}/start
    Server->>Platform: Transition broadcast to LIVE
```

---

## 4. Technology Stack Comparison

### 4.1 Application Layer

| Component | Hub | Control |
|-----------|-----|---------|
| **Language** | Rust (95%) + Kotlin (JNI) | Kotlin (100%) |
| **UI Framework** | Leptos 0.8.2 (Rust WASM) | Jetpack Compose (2024.09 BOM) |
| **App Framework** | Tauri v2.6.2 | Native Android |
| **Styling** | TailwindCSS v4 | Material Design 3 |
| **State Mgmt** | Leptos reactive signals | StateFlow + collectAsStateWithLifecycle |
| **DI** | None (manual wiring) | Hilt 2.59.2 |
| **Navigation** | Leptos Router | Compose Navigation 2.8.4 |
| **Local Storage** | Platform credential store | Room 2.8.4 + EncryptedSharedPreferences |
| **HTTP Client** | reqwest (rustls TLS) | Retrofit 2.11.0 + OkHttp 4.12.0 |
| **JSON** | serde_json | Moshi 1.15.1 |
| **Auth SDK** | Meta Horizon Platform SDK 77.0.1 | Meta Horizon Platform SDK 77.0.1 |
| **Crash Reporting** | Sentry (Android SDK bridge) | None |

### 4.2 Backend Layer

| Component | Hub Backend | Control Backend |
|-----------|-------------|-----------------|
| **Hosting** | Cloud (`api.obi.gg`) | Self-hosted (Docker on NAS, port 3100) |
| **Protocol** | JSON-RPC 2.0 | REST (JSON) |
| **Stack** | Unknown (external) | Node.js 20 + Fastify 5 + TypeScript 5.7 |
| **Database** | Unknown | SQLite (Prisma 6.4 ORM) |
| **Auth** | JWT (via JSON-RPC response headers) | JWT HS256 (jose 6.0) |
| **Token Security** | Unknown | AES-256-GCM encryption + SHA256 hashing |
| **OAuth** | Server handles YouTube/Twitch | Server handles YouTube/Twitch |
| **Rate Limiting** | Unknown | 100 req/min (Fastify plugin) |
| **Deployment** | Managed cloud | Docker + docker-compose |

### 4.3 UE5 Plugin Layer

| Component | LCKStreaming (Hub) | LCKControl (Companion) |
|-----------|-------------------|----------------------|
| **Communication** | HTTP/JSON-RPC 2.0 | AIDL via JNI |
| **Transport** | HTTPS (cross-network) | Local IPC (same device) |
| **Auth Flow** | Device code (6-digit) + polling | Direct service binding |
| **Token Storage** | EncryptedSharedPreferences | None (companion owns tokens) |
| **RTMP Sinks** | 1 (single destination) | N (multi-destination) |
| **Blocking Model** | Async HTTP callbacks | Synchronous JNI calls |
| **Platform Support** | Cross-platform capable | Android only |
| **Latency** | Network round-trip (100ms+) | IPC (~1ms) |
| **Offline Capable** | No (requires server) | Partial (companion has local cache) |

---

## 5. Streaming Architecture Deep Dive

### 5.1 Hub: Screen Capture + Re-Encoding

```mermaid
graph LR
    subgraph "UE5 Game Process"
        Render["Game Renderer<br/>(GPU)"]
    end

    subgraph "Android OS"
        FB["Framebuffer /<br/>Display Compositor"]
        MP["MediaProjection<br/>(Screen Capture API)"]
    end

    subgraph "Hub App Process"
        VD["VirtualDisplay"]
        MC_V["MediaCodec<br/>(H.264 Encoder)"]
        MC_A["MediaCodec<br/>(AAC Encoder)"]
        AR["AudioRecord<br/>(System Audio)"]
        MR["minirtmp<br/>(RTMP Client)"]
    end

    subgraph "CDN"
        RTMP["YouTube / Twitch<br/>RTMP Ingest"]
    end

    Render --> FB
    FB --> MP
    MP --> VD
    VD --> MC_V
    AR --> MC_A
    MC_V --> MR
    MC_A --> MR
    MR --> RTMP

    style FB fill:#fbb,stroke:#333
    style MP fill:#fbb,stroke:#333
```

**Problems:**
- Extra GPU copy through display compositor
- Re-encoding already rendered frames (quality loss)
- Higher latency (capture → encode → send)
- Higher battery/thermal impact (two encoding passes)
- Captures UI overlays, notifications, system bars
- Resolution limited to display resolution

### 5.2 Control: Direct Render Pipeline Encoding

```mermaid
graph LR
    subgraph "UE5 Game Process"
        Render["Game Renderer<br/>(GPU)"]
        SCC["SceneCaptureComponent2D<br/>(Render Target)"]
        ENC["LCK Encoder<br/>(H.264 + AAC)"]
        S1["RTMP Sink 1<br/>(YouTube)"]
        S2["RTMP Sink 2<br/>(Twitch)"]
        S3["RTMP Sink 3<br/>(Custom)"]
    end

    subgraph "CDN"
        YT["YouTube RTMP"]
        TW["Twitch RTMP"]
        CU["Custom RTMP"]
    end

    Render --> SCC
    SCC --> ENC
    ENC --> S1
    ENC --> S2
    ENC --> S3
    S1 --> YT
    S2 --> TW
    S3 --> CU

    style SCC fill:#bfb,stroke:#333
    style ENC fill:#bfb,stroke:#333
```

**Advantages:**
- Direct GPU texture access (no compositor overhead)
- Single encode pass (game scene only, no UI clutter)
- Lower latency
- Lower battery/thermal impact
- Configurable resolution independent of display
- Multi-destination from single encode
- Clean game footage (no system overlays)

---

## 6. Feature Comparison Matrix

| Feature | Hub | Control | Notes |
|---------|:---:|:-------:|-------|
| **Meta/Quest Login** | Yes | Yes | Both use Horizon Platform SDK 77.0.1 |
| **YouTube OAuth** | Yes | Yes | Both server-side token exchange |
| **Twitch OAuth** | Yes | Yes | Both server-side token exchange |
| **Multi-Destination Streaming** | No (1) | Yes (N) | Major difference |
| **Stream Plans** | No | Yes | Control has full lifecycle management |
| **Direct Game Encoding** | No | Yes | Control encodes from render pipeline |
| **Screen Capture Streaming** | Yes | No | Hub captures and re-encodes |
| **Custom RTMP Targets** | Yes | Yes | Both support manual RTMP |
| **Game Client Management** | Yes (pairing) | Yes (AIDL) | Different mechanisms |
| **IGDB Game Database** | Yes | No | Hub has game cover art |
| **Watermark** | Yes | No | Hub has overlay support |
| **Subscription Model** | Yes | No | Hub has paid tier |
| **Sentry Crash Reporting** | Yes | No | Hub has telemetry |
| **Certificate Pinning** | Yes | No | Hub has SPKI pinning |
| **Offline Caching** | No | Yes | Control has Room DB |
| **Background Token Refresh** | Unknown | Yes | Control backend has scheduler |
| **CI/CD Pipeline** | Yes (Jenkins) | Partial (deploy.ps1) | Hub has full CI |
| **Desktop Support** | Yes | No | Tauri supports desktop |
| **Cross-Platform** | Yes (Desktop + Android) | No (Android only) | Hub has wider reach |

---

## 7. Pros and Cons

### 7.1 Hub (liv-control-center)

#### Pros
- **Cross-platform**: Tauri supports Desktop + Android, one codebase
- **Self-contained streaming**: No dependency on game integration
- **Works with any game**: Screen capture works regardless of game engine support
- **Production infrastructure**: Jenkins CI/CD, Sentry, cloud backend
- **Rich features**: IGDB, watermarks, subscription model
- **Rust performance**: Memory-safe, low-level control over encoding

#### Cons
- **Screen capture quality**: Re-encoding degrades quality, captures overlays
- **Higher resource usage**: Extra GPU copy + encode pass drains battery faster
- **Single destination**: Can only stream to one platform at a time
- **Complex stack**: Rust + WASM + Tauri + Kotlin JNI is hard to maintain
- **Server dependency**: All communication goes through cloud backend
- **Latency**: Network round-trips for game communication (polling every 2.5s)
- **Low store reviews**: Users experiencing issues (reason for this analysis)
- **Niche UI framework**: Leptos (WASM) has small ecosystem vs Compose
- **No stream plans**: Simple streaming model without plan lifecycle

### 7.2 Control App (lck-control)

#### Pros
- **Direct render pipeline**: Game encodes from GPU, best possible quality
- **Multi-destination**: Stream to YouTube + Twitch + custom simultaneously
- **Low latency IPC**: AIDL communication in ~1ms vs 100ms+ network calls
- **Stream plans**: Full lifecycle (DRAFT → READY → LIVE → ENDED)
- **Clean architecture**: Standard Android stack (Compose, Hilt, Room, Retrofit)
- **Own backend**: Full control over API, auth, token management
- **SDK module**: Clean AAR for UE5 consumption via JNI
- **Lower resource usage**: No screen capture or re-encoding overhead
- **Maintainable**: Kotlin + Compose is mainstream Android with large ecosystem
- **Offline caching**: Room DB + encrypted token store

#### Cons
- **Android only**: No desktop support
- **Requires game integration**: Game must use LCKControl plugin (not universal)
- **Prototype stage**: Not production-ready yet
- **Self-hosted backend**: Requires infrastructure management (Docker on NAS)
- **No CI/CD**: Manual builds via PowerShell script
- **No crash reporting**: No Sentry or equivalent
- **No subscription model**: No monetization built in
- **No IGDB integration**: No game metadata/artwork
- **Blocking IPC**: Synchronous JNI calls could cause ANRs if slow

---

## 8. UE5 Plugin Comparison

### 8.1 LCKStreaming Plugin (uses Hub)

```mermaid
stateDiagram-v2
    [*] --> Idle
    Idle --> LoggingIn: StartLogin()
    LoggingIn --> WaitingForCode: create_device_login_attempt
    WaitingForCode --> Polling: Display 6-digit code
    Polling --> Authenticated: check_device_login_attempt<br/>(every 2.5s)
    Polling --> Polling: Not yet paired
    Authenticated --> FetchingProfile: get_user_profile
    FetchingProfile --> Ready: Got RTMP target
    Ready --> Streaming: StartStreaming()
    Streaming --> Ready: StopStreaming()
    Ready --> Idle: Logout()

    note right of Polling
        User must manually enter
        code in Hub app or website
    end note
```

**Architecture:**
- `ULCKStreamingSubsystem` — GameInstance subsystem, owns API client + RTMP sink
- `FLCKStreamingApiClient` — HTTP client, JSON-RPC 2.0, cert pinning
- `FLCKRtmpSink` / `FLCKRtmpClient` — Single RTMP connection via librtmp
- Auth token stored in platform credential store
- Single streaming target resolved by backend

### 8.2 LCKControl Plugin (uses Companion App)

```mermaid
stateDiagram-v2
    [*] --> Disconnected
    Disconnected --> Connecting: ConnectToCompanionApp()
    Connecting --> Connected: AIDL service bound<br/>(poll every 1s)
    Connected --> HasPlans: GetStreamPlans()
    HasPlans --> Prepared: PrepareStreamPlan(planId)<br/>→ RTMP URLs resolved
    Prepared --> Streaming: StartStreamPlan(planId)<br/>+ Attach N RTMP sinks
    Streaming --> Prepared: EndStreamPlan(planId)
    Connected --> Disconnected: DisconnectFromCompanionApp()

    note right of Connected
        Direct AIDL binding,
        no pairing code needed
    end note

    note right of Streaming
        Multiple RTMP sinks active
        simultaneously
    end note
```

**Architecture:**
- `ULCKControlSubsystem` — GameInstance subsystem, owns JNI bridge + multiple RTMP sinks
- `LCKControlAndroid.cpp` — ~700 lines of JNI bindings to `LckControlClient` (AAR)
- Multiple `FLCKRtmpSink` instances — one per stream destination
- No token management — companion app handles all auth
- Full stream plan lifecycle control

### 8.3 Shared Infrastructure (LCK Base Plugin)

Both plugins share:
- `ILCKStreamingFeature` — Common interface (StartLogin, StartStreaming, StopStreaming, etc.)
- `ILCKEncoderFactory` — Encoder creation
- `ULCKRecorderSubsystem` — Encoder lifecycle management
- `FLCKRtmpSink` / `FLCKRtmpClient` — RTMP transport layer
- H.264 + AAC encoding via platform-specific backends (NVCodec, MediaCodec)

---

## 9. Backend Comparison

### 9.1 Hub Backend (`api.obi.gg`)

```mermaid
graph TB
    subgraph "Cloud (Managed)"
        API_H["Hub Backend API"]
        DB_H["Database<br/>(Unknown)"]
        IGDB["IGDB API<br/>(Game Metadata)"]
    end

    Hub["Hub App"] -->|"JSON-RPC 2.0<br/>POST /api/rpc"| API_H
    Game_S["LCKStreaming<br/>Plugin"] -->|"JSON-RPC 2.0<br/>POST /api/rpc"| API_H
    API_H --> DB_H
    API_H --> IGDB

    style API_H fill:#f96,stroke:#333
```

**Known RPC Methods:**
- `LoginUser`, `RefreshUser` — Auth
- `ListMyStreamingTargets`, `CreateStreamingTarget`, `UpdateStreamingTarget`, `DeleteStreamingTarget` — Targets
- `PairDevice`, `UnpairDevice`, `GetConnectedGames` — Device management
- `StartStreaming`, `StopStreaming` — Stream events
- `SearchIgdbGames` — Game metadata
- `CreateOauthConnectIntent`, `GetOauthConnectIntent` — OAuth

### 9.2 Control Backend (`lck-control-backend`)

```mermaid
graph TB
    subgraph "Self-Hosted (Docker on NAS)"
        API_C["Fastify 5 API<br/>(TypeScript)"]
        Prisma["Prisma 6.4 ORM"]
        SQLite["SQLite DB"]
        Scheduler["Token Refresh<br/>Scheduler (10min)"]
    end

    App["Control App"] -->|"REST API<br/>JWT Bearer Auth"| API_C
    API_C --> Prisma --> SQLite
    Scheduler --> API_C

    API_C -->|OAuth| Google["Google OAuth"]
    API_C -->|OAuth| Twitch_API["Twitch OAuth"]
    API_C -->|Nonce Validate| Meta_Graph["Meta Graph API"]
    API_C -->|Live API| YT_API["YouTube Live API"]
    API_C -->|Helix API| TW_API["Twitch Helix API"]

    style API_C fill:#9cf,stroke:#333
```

**REST Endpoints:**
| Group | Endpoints |
|-------|-----------|
| Auth | `POST /auth/meta/callback`, `POST /auth/refresh`, `GET /auth/me`, `POST /auth/logout` |
| Providers | `GET /providers/accounts`, `GET /providers/{yt\|tw}/auth-url`, `POST /providers/{yt\|tw}/callback`, `DELETE /providers/:serviceId` |
| Streams | `GET /streams/plans`, `POST /streams/plans`, `GET /streams/plans/:id`, `DELETE /streams/plans/:id` |
| Lifecycle | `POST /streams/plans/:id/prepare`, `POST /streams/plans/:id/start`, `POST /streams/plans/:id/end` |

---

## 10. Data Flow Comparison

### 10.1 Hub: Centralized Server Model

```mermaid
graph LR
    subgraph "Data Ownership"
        direction TB
        Server_H["Hub Backend<br/>(owns ALL data)"]
    end

    Hub_App["Hub App<br/>(thin client)"] <-->|"All state via<br/>JSON-RPC"| Server_H
    Game_H["UE5 Game<br/>(paired device)"] <-->|"All state via<br/>JSON-RPC"| Server_H
    YT_H["YouTube API"] <--> Server_H
    TW_H["Twitch API"] <--> Server_H

    style Server_H fill:#f96,stroke:#333
```

- **Single source of truth**: Backend server
- **No local cache**: App relies on network for all state
- **Game is decoupled**: Only communicates with server, never with app
- **Offline = broken**: Cannot function without server connectivity

### 10.2 Control: Distributed Ownership Model

```mermaid
graph LR
    subgraph "Data Ownership"
        direction TB
        Server_C["Control Backend<br/>(tokens, plans,<br/>OAuth)"]
        App_C["Control App<br/>(local cache,<br/>session tokens)"]
        Game_C["UE5 Game<br/>(RTMP streams)"]
    end

    App_C <-->|REST API| Server_C
    Game_C <-->|"AIDL IPC<br/>(stream plans,<br/>RTMP config)"| App_C
    Server_C <--> YT_C["YouTube API"]
    Server_C <--> TW_C["Twitch API"]
    Game_C -->|"RTMP<br/>(direct)"| CDN["YouTube / Twitch<br/>RTMP Ingest"]

    style App_C fill:#9f9,stroke:#333
    style Game_C fill:#9cf,stroke:#333
```

- **Distributed state**: Backend (tokens, plans), App (cache, session), Game (streams)
- **Local caching**: Room DB provides offline access to plans and accounts
- **Game is tightly coupled**: Direct IPC with companion app
- **Partial offline**: Can view cached plans without network

---

## 11. Unification Strategy

### 11.1 Recommended Direction: Evolve Control App into Production

The Control architecture is fundamentally superior for game streaming because:

1. **Direct encode > screen capture** — Quality, performance, and battery life
2. **Multi-destination > single target** — Key user-facing feature
3. **IPC > server polling** — Reliability and responsiveness
4. **Stream plans > ad-hoc streaming** — Better UX for recurring setups
5. **Standard Android stack > Rust/WASM** — Easier maintenance and hiring

### 11.2 Migration Roadmap

```mermaid
gantt
    title Unification Roadmap
    dateFormat YYYY-MM-DD
    axisFormat %b %Y

    section Phase 1: Production Readiness
    CI/CD pipeline (Jenkins/GH Actions)        :p1a, 2026-03-01, 14d
    Sentry crash reporting                      :p1b, 2026-03-01, 7d
    Backend deploy to cloud                     :p1c, 2026-03-08, 7d
    Certificate pinning (OkHttp)                :p1d, 2026-03-08, 3d

    section Phase 2: Feature Parity
    IGDB game metadata integration              :p2a, 2026-03-15, 7d
    Watermark / overlay support in encoder      :p2b, 2026-03-15, 10d
    Subscription model + paywall                :p2c, 2026-03-22, 14d

    section Phase 3: Hub Migration
    Add fallback screen-capture mode            :p3a, 2026-04-05, 14d
    Port device pairing (for non-integrated games) :p3b, 2026-04-05, 10d
    Migrate Hub users to Control                :p3c, 2026-04-19, 14d
    Deprecate Hub app                           :p3d, 2026-05-03, 7d

    section Phase 4: Polish
    Desktop companion (optional)                :p4a, 2026-05-10, 21d
    Advanced stream analytics                   :p4b, 2026-05-10, 14d
    Store listing + marketing                   :p4c, 2026-05-24, 7d
```

### 11.3 What to Keep from Each

```mermaid
graph TB
    subgraph "Unified App"
        direction TB
        A["Control App Architecture<br/>(Kotlin + Compose + Hilt)"]
        B["Control Backend<br/>(Fastify + Prisma + SQLite)"]
        C["LCKControl Plugin<br/>(AIDL + multi-destination)"]
        D["Stream Plan System<br/>(DRAFT → READY → LIVE → ENDED)"]
    end

    subgraph "Adopt from Hub"
        E["Sentry Crash Reporting"]
        F["IGDB Game Database"]
        G["Certificate Pinning"]
        H["Jenkins CI/CD"]
        I["Watermark Renderer"]
        J["Screen Capture Fallback"]
    end

    subgraph "Discard"
        K["Rust/Tauri/Leptos Stack"]
        L["JSON-RPC 2.0 Protocol"]
        M["minirtmp (Rust RTMP)"]
        N["Device Code Pairing<br/>(replaced by AIDL)"]
        O["Single-Destination Limit"]
    end

    E --> A
    F --> B
    G --> A
    H --> A
    I --> C
    J --> A

    style A fill:#9f9,stroke:#333
    style B fill:#9cf,stroke:#333
    style C fill:#9f9,stroke:#333
    style D fill:#9f9,stroke:#333
    style K fill:#fbb,stroke:#333
    style L fill:#fbb,stroke:#333
    style M fill:#fbb,stroke:#333
    style N fill:#fbb,stroke:#333
    style O fill:#fbb,stroke:#333
```

### 11.4 Hybrid Mode: Screen Capture Fallback

To maintain the Hub's "works with any game" advantage, add a fallback path:

```mermaid
graph TB
    Start["Game Launches"] --> Check{"LCKControl Plugin<br/>integrated?"}
    Check -->|Yes| AIDL["AIDL IPC Path<br/>(direct encode,<br/>multi-destination)"]
    Check -->|No| Capture["Screen Capture Path<br/>(MediaProjection,<br/>single destination)"]
    AIDL --> Stream["Stream to Platforms"]
    Capture --> Stream

    style AIDL fill:#9f9,stroke:#333
    style Capture fill:#ff9,stroke:#333
```

This gives the unified app both modes:
- **Primary**: Direct encoding via AIDL (high quality, multi-destination)
- **Fallback**: Screen capture for games without plugin integration (compatibility)

---

## 12. Risk Assessment

| Risk | Impact | Mitigation |
|------|--------|------------|
| Hub users lose access during migration | High | Run both apps in parallel during transition, provide migration guide |
| AIDL only works on Android (no desktop) | Medium | Screen capture fallback for desktop; evaluate PCVR needs later |
| Self-hosted backend scalability | Medium | Move to managed cloud (Railway, Fly.io) before store launch |
| Synchronous JNI blocking causes ANR | Medium | Add timeout handling, move to async callback pattern |
| No subscription model in Control | Low | Implement before store launch using existing Hub billing logic |
| Losing crash telemetry | Low | Add Sentry SDK early in Phase 1 |

---

## 13. Summary Decision Matrix

```mermaid
quadrantChart
    title Streaming Quality vs Maintenance Complexity
    x-axis Low Maintenance --> High Maintenance
    y-axis Low Quality --> High Quality
    quadrant-1 Ideal
    quadrant-2 Overengineered
    quadrant-3 Avoid
    quadrant-4 Quick & Dirty

    Control App: [0.35, 0.85]
    Hub App: [0.75, 0.45]
    Unified - Recommended: [0.45, 0.90]
```

**Recommendation**: The Control App architecture with adopted Hub features provides the best path forward — higher streaming quality with a more maintainable stack. The Hub's Rust/Tauri/Leptos stack adds significant complexity without proportional benefits for an Android-focused product.

---

*Document generated 2026-02-26. Based on analysis of `liv-control-center`, `lck-control`, `lck-control-backend`, and `LCKGame` codebases.*