flutter_lite_camera 0.2.1

A Flutter camera plugin for Android, iOS, web, Windows, macOS, and Linux with native previews and RGB frame capture.

Flutter Lite Camera

Flutter Lite Camera is a lightweight Flutter plugin designed for capturing camera frames in RGB888 format. The plugin supports Windows, Linux, macOS, iOS, Android, and web, making it ideal for building camera preview applications and performing image processing tasks with any recognition SDK. The default target resolution is 640x480; each platform negotiates with the device and every frame reports its actual width and height.

Features

• Cross-Platform: Compatible with Windows, Linux, macOS, iOS, Android, and web.
• Zero-Copy Preview: Renders the video feed directly at the native layer — a FlutterTexture fed by BGRA buffers on iOS/macOS, an engine SurfaceTexture on Android, and an embedded getUserMedia video element on the web. No per-frame data copies into Dart.
• RGB888 Frame Format: Captures uncompressed RGB888 frames on demand for easy image processing, without disturbing the preview stream.
• Simple Integration: Easy-to-use API for seamless Flutter integration.

Requirements

• Flutter SDK: 3.27 (Dart 3.6) or above. Flutter 3.44 or above is required when the host app enables Swift Package Manager for iOS or macOS.

• Web: The page must be served over HTTPS (or localhost) for getUserMedia to work.

• macOS / iOS permissions: Ensure camera access is granted.

  • macOS — in DebugProfile.entitlements or Release.entitlements, add:

    <key>com.apple.security.device.camera</key>
    <true/>
    

  • iOS — in Runner/Info.plist, add:

    <key>NSCameraUsageDescription</key>
    <string>The app uses the camera.</string>
    

• Android permissions: The plugin requests the CAMERA runtime permission automatically when open() is called as long as the app declares it:

  <uses-permission android:name="android.permission.CAMERA"/>
  

  Add the declaration to android/app/src/main/AndroidManifest.xml.

API

Method	Description
getDeviceList()	Returns a list of available camera devices.
open(int index)	Opens the camera at the specified index.
startPreview()	Starts the preview stream and returns a texture id to pass to buildPreview().
buildPreview(textureId)	Returns the preview widget: a Texture on native platforms, an embedded video element on the web.
stopPreview()	Stops the preview stream.
captureFrame()	Captures a single frame as an RGB888 image. While a preview is running, the frame comes from a native cache and the stream is unaffected.
getRotation()	Returns the clockwise degrees (0/90/180/270) to apply to the preview and decoded coordinates so they appear upright (typically 90 on iOS phones, 0 elsewhere — Android frames already arrive display-oriented).
setResolution(int width, int height)	Requests a capture size; the platform negotiates the closest supported size instead of failing when the exact one is unavailable.
setResolutionPreset(ResolutionPreset preset)	Same, using a preset: low (320x240), medium (640x480), high (1280x720), veryHigh (1920x1080), ultraHigh (3840x2160), max (device maximum).
getWidth() / getHeight()	Returns the actual negotiated frame size, in display orientation.
release()	Releases the camera resources.

Usage

final camera = FlutterLiteCamera();

final devices = await camera.getDeviceList();
if (devices.isNotEmpty) {
  await camera.open(0);

  // Optional: pick a resolution. The platform negotiates the closest
  // supported size; getWidth()/getHeight() report the actual result.
  await camera.setResolutionPreset(ResolutionPreset.veryHigh); // 1920x1080

  // Preview: display the returned texture id with buildPreview, which picks
  // the right widget for the platform (Texture on native, a video element on
  // the web).
  final int textureId = await camera.startPreview();
  // ... SizedBox(... child: camera.buildPreview(textureId))

  // Decode: grab a single frame whenever you need one (e.g. for barcode
  // scanning). This does not interrupt the preview.
  final frame = await camera.captureFrame();
  final Uint8List rgb = frame['data'];   // RGB888, width * height * 3 bytes
  final int width = frame['width'];
  final int height = frame['height'];

  // Rotate the preview widget and decoded coordinates by this angle so they
  // display upright (typically 90 on iOS phones, 0 elsewhere).
  final int rotation = await camera.getRotation();

  await camera.stopPreview();
  await camera.release();
}

Platform notes

Platform	Preview path	captureFrame() source	Permission handling
Windows	Native texture (CameraWindows.cpp)	RGB frame cache	—
Linux	Native texture (CameraLinux.cpp, V4L2)	RGB frame cache	—
macOS	Native texture (AVFoundation BGRA)	Latest BGRA pixel buffer	Entitlements + TCC
iOS	Native texture (AVFoundation BGRA)	Latest BGRA pixel buffer	Info.plist + AVCaptureDevice.requestAccess
Android	SurfaceTexture fed by Camera2	Latest YUV_420_888 frame, converted to RGB888	AndroidManifest.xml + runtime request
Web	getUserMedia video element in a platform view	Snapshot drawn via an ImageData pass	Browser prompt (HTTPS required)