Flutter app — DVR/HLS player for iPad tablets, with multi-slot support and real-time WebSocket. Based on VLCKit (MobileVLCKit) with a custom native VLC player (MethodChannel + direct VLCKit).

Video Player

Feature	What it does
3 streaming slots	MAIN, FEED, ALT — 3 simultaneous HLS video players in a vertical layout
Fullscreen	Tap a video to expand it to full screen
DVR	Timeline bar to seek back in time, return to live with a tap
Auto-advance live	Automatic return to live after N seconds of inactivity on the DVR
LIVE/DVR badge	Colored badge: red for live, blue for DVR
Video controls	Play/pause, seek, volume (headphone-only audio), fullscreen toggle
Headphone audio	Volume at 0.0 by default, activates automatically only with headphones connected
BoxFit cover	Videos fill the screen while keeping proportions, no side black bars
Live/Go Live	Blue button for DVR, red for live streaming

Connection

Feature	What it does
Persistent WebSocket	Continuous connection to the backend to receive real-time updates
Exponential backoff	Automatic reconnection with progressive delay (1s, 2s, 4s, 8s, max 30s)
Configurable	Backend URL passed via --dart-define=BACKEND_URL=..., nothing hardcoded
Remote reset	Receives the device:reset command to restart all streams without restarting the app
Remote slot control	Receives the device:slot:control command to stop/start/restart a single slot

Stream switching

Feature	What it does
Automatic switch	When the Control Room changes a link, all iPads switch to the new stream in real time
Free slot	When a slot is freed, the video stops and waits for the next stream
Track last URLs	On reset, the app remembers the last valid URLs and restores them after 500ms

Requirements

Tool	Version
Flutter	3.44.4+
Dart	3.12.2+
Xcode	16+ (for iOS build)
CocoaPods	(for iOS dependencies)

Player Dependencies

Package	Role
MobileVLCKit (pod)	VLC playback engine (declared in ios/Podfile)
web_socket_channel	Real-time WebSocket to the backend (ws_link_service.dart)
audio_session	Audio session configuration
shared_preferences	Settings persistence

Architecture

lib/
├── main.dart                  # Flutter entry point → VlcCustomTestScreen
├── vlc_custom_test_screen.dart # Main custom VLC player screen
├── vlc/
│   ├── vlc_controller.dart    # VLC controller (playback, stall watchdog, retry)
│   ├── vlc_controls.dart      # Video controls overlay
│   ├── vlc_timeline_widget.dart # Interactive DVR timeline
│   ├── dvr_support_probe.dart # Server DVR capability detection
│   └── dvr_url_strategy.dart  # DVR URL strategies (Flussonic/Wowza)
├── vlc_native_player.dart     # Native VLC bridge (MethodChannel)
├── switch_timing.dart         # Slot transition timing
├── dvr_range.dart             # DVR range data model
├── link_service.dart          # REST service (legacy, unused)
└── ws_link_service.dart       # WebSocket service (active)

Test

# Run all tests
flutter test

# Run only the VLC controller tests
flutter test test/vlc_controller_test.dart test/vlc_controller_state_test.dart

App Store Notes

The app is designed as a LAN kiosk: it connects via HTTP to a private IP (e.g. 192.168.1.127:3002). For App Store submission you need the App Review Notes and the privacy policy (see Mac Setup and Complete Guide). ATS allows traffic to private IPs; NSAllowsLocalNetworking is configured in ios/Runner/Info.plist for the local network.

→ See Build Flutter App for setup, running and building.