Generating image files from CameraImage-CodePudding

We would like to use CameraController.startImageStream() instead of CameraController.takePicture() to get a return value equivalent to CameraController.takePicture(). We know that various answers have been documented for these but we have not yet succeeded with any of the methods.

We have implemented the following. We tried setting the imageFormatGroup during CameraController generation, but this did not improve things. We have to make these work on both Android and iOS. We want a way to run it faster. It can be written in Flutter or using C and ffi.

import 'package:image/image.dart' as imglib;

final cameras = await availableCameras();

final firstCamera = cameras.first;

cameraController = CameraController(
  firstCamera,
  ResolutionPreset.medium,
//  imageFormatGroup: ImageFormatGroup.yuv420,
);

await cameraController!.initialize();

await cameraController!.startImageStream((CameraImage cameraImage) async {
      cameraController!.stopImageStream();

      Uint8List list = cameraImage.planes.first.bytes;
      final width = cameraImage.width;
      final height = cameraImage.height;
      imglib.Image test = imglib.Image.fromBytes(width, height, list);

      List<int> _imageBytes = imglib.encodeJpg(test);
      Uint8List convert = Uint8List.fromList(_imageBytes);
      File file = File.fromRawPath(convert);
      XFile? result = XFile(file.path);
});

Index out of range occurred when we called encodeJpg(). How should we fix this?

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