voxa_deepar 0.1.2

DeepAR camera effects for VoxaRTC. Runs on the capture path, before the encoder, so the room sees the effect rather than the streamer previewing it.

example/lib/main.dart

// Camera effects on a live VoxaRTC engine.
//
// The effect runs on the capture path, before the encoder, so it is in the
// published stream — everyone in the room sees it, not just you.
//
// Two things this file cannot supply, because they are yours:
//   * a DeepAR licence key, bound to this app's application id
//   * a .deepar effect file in assets/
//
// See README.md.
import 'package:flutter/material.dart';
import 'package:voxa_deepar/voxa_deepar.dart';
import 'package:voxa_rtc_engine/voxa_rtc_engine.dart';

/// Your VoxaRTC app id.
const appId = 'YOUR_APP_ID';

/// Your DeepAR licence key. Keys are per-platform and bound to the
/// application id — DeepAR fails *silently* on a mismatch, so if effects do
/// nothing and nothing is logged, check this first.
const deepArKey = 'YOUR_DEEPAR_KEY';

/// An effect you dropped into assets/.
const effectAsset = 'assets/my_effect.deepar';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  runApp(const MaterialApp(home: EffectsDemo()));
}

class EffectsDemo extends StatefulWidget {
  const EffectsDemo({super.key});

  @override
  State<EffectsDemo> createState() => _EffectsDemoState();
}

class _EffectsDemoState extends State<EffectsDemo> {
  // Lazy initialisers, not assignments in _start(). build() runs the moment
  // the widget mounts, well before the engine has finished initialising, and
  // the button below reads _effects.isSupported — so assigning it after an
  // await meant the first frames rendered a LateInitializationError. Both
  // constructors are synchronous and cheap, so first access is safe.
  late final RtcEngine _engine = createAgoraRtcEngine();
  late final VoxaDeepAr _effects = VoxaDeepAr(_engine);
  VideoViewController? _preview;
  bool _on = false;
  String _status = 'starting';

  @override
  void initState() {
    super.initState();
    _start();
  }

  Future<void> _start() async {
    await _engine.initialize(const RtcEngineContext(appId: appId));
    await _engine.enableVideo();
    await _engine.startPreview();

    await _effects.setLicenseKey(deepArKey);

    setState(() {
      _preview = VideoViewController(
          rtcEngine: _engine, canvas: const VideoCanvas(uid: 0));
      _status = _effects.isSupported
          ? 'camera on — tap to apply the effect'
          : 'effects are not available on this platform';
    });
  }

  Future<void> _toggle() async {
    if (_on) {
      await _effects.clear();
      setState(() {
        _on = false;
        _status = 'effect off — raw camera';
      });
      return;
    }

    // DeepAR reads effects from disk, so the bundled asset is copied out of
    // the bundle first. Null means it is not in this build.
    final path = await VoxaDeepAr.stageAsset(effectAsset);
    if (path == null) {
      setState(() => _status = 'no effect found at $effectAsset');
      return;
    }

    // setEffect enables on the first call, so this is the only step between
    // a raw camera and a running effect.
    final ok = await _effects.setEffect(path);
    setState(() {
      _on = ok;
      _status = ok ? 'effect on — the room sees this too' : 'could not apply';
    });
  }

  @override
  void dispose() {
    // The native filter outlives this engine, so an effect left enabled would
    // still be attached the next time a camera starts.
    _effects.clear();
    _engine.release();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final preview = _preview;
    return Scaffold(
      backgroundColor: Colors.black,
      body: Stack(children: [
        if (preview != null)
          Positioned.fill(child: AgoraVideoView(controller: preview)),
        Positioned(
          left: 16,
          right: 16,
          bottom: 48,
          child: Column(mainAxisSize: MainAxisSize.min, children: [
            Container(
              padding: const EdgeInsets.all(10),
              color: Colors.black54,
              child: Text(_status,
                  style: const TextStyle(color: Colors.white, fontSize: 13)),
            ),
            const SizedBox(height: 12),
            ElevatedButton(
              // Gate on isSupported rather than assuming: a button that always
              // fails is worse than no button.
              onPressed:
                  preview == null || !_effects.isSupported ? null : _toggle,
              child: Text(_on ? 'Turn effect off' : 'Turn effect on'),
            ),
          ]),
        ),
      ]),
    );
  }
}