Third-party Integration

SDK 2.0.0. Flutter only sets beauty parameters. Live frames never enter Dart: call FacebetterPlugin.processTexture on the vendor SDK’s native GL thread, then write the output texture back.

Flutter (Dart)                              Native GL thread (iOS / Android)
FBEngine.create(externalContext: true)
engine.setSmoothing / setReshape / …  →     Vendor preprocess callback
await engine.setFilter                      FacebetterPlugin.processTexture(tex, w, h)
engine.dispose()                            Write back vendor textureId

Shared contract

Item	Requirement
Live engine	`externalContext: true` (default); `FBEngine.create` before enabling vendor custom preprocess
Frames	Native `FacebetterPlugin.processTexture` only; must run on the current GL thread
Stills	Separate engine with `externalContext: false`; never mix with the live engine
Input	Prefer vendor Texture2D / RGB (`GL_TEXTURE_2D`); convert OES / YUV first or change format per vendor docs
Tear-down	Disable vendor preprocess / stop tracks, then `engine.dispose()`

Do not call processFile / processImageBytes / processImageFile / processImageToUiImage on the live engine.

import 'package:facebetter_flutter/facebetter_flutter.dart';

FBEngine.setLogConfig(console: true, level: FBLogLevel.info);

final engine = await FBEngine.create(const FBEngineConfig(
  appId: 'your_app_id',
  appKey: 'your_app_key',
  externalContext: true,
  enableLandmarks: false,
));

engine.setSmoothing(0.8);
engine.setWhitening(0.5);
engine.setReshape(FBReshape.faceThin, 0.3);
engine.setLipstick(0.4);
await engine.setFilter(path: '/path/to/filter.fbd');

// Sliders can call sync setters directly:
// onChanged: (v) => engine.setSmoothing(v),

Credentials: Subscription, Auth & License. Native texture rules: Android · Third-party Integration, iOS · Third-party Integration.

	Live engine	Photo engine
`externalContext`	`true` (default)	`false`
Frames	Native `processTexture`	Dart `processFile` / `processImageBytes` / …
Mixing	No photo APIs	Not for live / meeting preprocess

Do not: push pixels or texture ids from Dart every frame; call processTexture off the GL thread; treat FBEngine as a process-wide singleton.

TRTC (Tencent)

Prerequisites: tencent_trtc_cloud (or native TRTC) and facebetter_flutter: ^2.0.0. When enabling custom preprocess, use Texture2D + Texture buffer, not YUV / PixelBuffer. After creating the engine in Dart, enable custom process (API name may vary by plugin version):

await trtcCloud.enableCustomVideoProcess(true);

iOS — `onProcessVideoFrame`

#import <facebetter_flutter/FacebetterPlugin.h>

- (uint32_t)onProcessVideoFrame:(TRTCVideoFrame *)srcFrame
                        dstFrame:(TRTCVideoFrame *)dstFrame {
  uint32_t out = [FacebetterPlugin processTexture:srcFrame.textureId
                                            width:srcFrame.width
                                           height:srcFrame.height];
  if (out != 0) {
    dstFrame.textureId = out;
  }
  return 0;
}

If you use tencent_trtc_cloud’s ITXCustomBeautyProcesser, keep Texture2D / Texture and call the same processTexture in the callback. Register the factory after GeneratedPluginRegistrant.register(with:).

Android — Kotlin

import net.pixpark.facebetter.flutter.FacebetterPlugin

override fun onProcessVideoFrame(
    srcFrame: TRTCCloudDef.TRTCVideoFrame,
    dstFrame: TRTCCloudDef.TRTCVideoFrame,
): Int {
    val out = FacebetterPlugin.processTexture(
        srcFrame.texture.textureId,
        srcFrame.width,
        srcFrame.height,
    )
    if (out != 0) {
        dstFrame.texture.textureId = out
    }
    return 0
}

Tear-down

await trtcCloud.enableCustomVideoProcess(false);
engine.dispose();

Agora

Same model as native: call FacebetterPlugin.processTexture inside the iOS / Android frame observer / custom preprocess callback; Dart only owns FBEngine parameters.

Dart: FBEngine.create(externalContext: true) and set beauty
Enable custom video processing or register a native observer per the Agora Flutter plugin (APIs vary by agora_rtc_engine version)
On a GL_TEXTURE_2D textureId, call processTexture and write back to the vendor frame

For OES / YUV-only callbacks, convert to Texture2D first, or see Android / iOS (Flutter live path still prefers texture + processTexture). Tear-down: unregister Agora preprocess, then engine.dispose().

LiveKit

Again: Dart sets parameters, native processes textures.

Create an externalContext: true engine in Dart
Obtain texture frames via LiveKit Flutter / a native custom capturer or video processor
Call FacebetterPlugin.processTexture on the GL thread, then feed the output back into the LiveKit track

Hook details vary by livekit_client and platform; texture rules: Android · LiveKit, iOS · LiveKit.

Introduction

Android

iOS

macOS

Windows

Linux

Web

Flutter

Shared contract

TRTC (Tencent)

iOS — `onProcessVideoFrame`

Android — Kotlin

Tear-down

Agora

LiveKit

​Shared contract

​TRTC (Tencent)

​iOS — onProcessVideoFrame

​Android — Kotlin

​Tear-down

​Agora

​LiveKit

​Related

Shared contract

TRTC (Tencent)

iOS — `onProcessVideoFrame`

Android — Kotlin

Tear-down

Agora

LiveKit

Related