Camera Plugin

A Flutter plugin for iOS, Android and Web allowing access to the device cameras.

Features

• Display live camera preview in a widget.
• Snapshots can be captured and saved to a file.
• Record video.
• Add access to the image stream from Dart.

Installation

First, add camera as a dependency in your pubspec.yaml file.

iOS

Add two rows to the ios/Runner/Info.plist:

• one with the key Privacy - Camera Usage Description and a usage description.
• and one with the key Privacy - Microphone Usage Description and a usage description.

If editing Info.plist as text, add:

<key>NSCameraUsageDescription</key>
<string>your usage description here</string>
<key>NSMicrophoneUsageDescription</key>
<string>your usage description here</string>

Android

Change the minimum Android sdk version to 21 (or higher) in your android/app/build.gradle file.

minSdkVersion 21

It‘s important to note that the MediaRecorder class is not working properly on emulators, as stated in the documentation: https://developer.android.com/reference/android/media/MediaRecorder. Specifically, when recording a video with sound enabled and trying to play it back, the duration won’t be correct and you will only see the first frame.

Web integration

For web integration details, see the camera_web package.

Handling Lifecycle states

As of version 0.5.0 of the camera plugin, lifecycle changes are no longer handled by the plugin. This means developers are now responsible to control camera resources when the lifecycle state is updated. Failure to do so might lead to unexpected behavior (for example as described in issue #39109). Handling lifecycle changes can be done by overriding the didChangeAppLifecycleState method like so:

@override
void didChangeAppLifecycleState(AppLifecycleState state) {
  final CameraController? cameraController = controller;

  // App state changed before we got the chance to initialize.
  if (cameraController == null || !cameraController.value.isInitialized) {
    return;
  }

  if (state == AppLifecycleState.inactive) {
    cameraController.dispose();
  } else if (state == AppLifecycleState.resumed) {
    onNewCameraSelected(cameraController.description);
  }
}

Handling camera access permissions

Permission errors may be thrown when initializing the camera controller, and you are expected to handle them properly.

Here is a list of all permission error codes that can be thrown:

• CameraAccessDenied: Thrown when user denies the camera access permission.

• CameraAccessDeniedWithoutPrompt: iOS only for now. Thrown when user has previously denied the permission. iOS does not allow prompting alert dialog a second time. Users will have to go to Settings > Privacy > Camera in order to enable camera access.

• CameraAccessRestricted: iOS only for now. Thrown when camera access is restricted and users cannot grant permission (parental control).

• AudioAccessDenied: Thrown when user denies the audio access permission.

• AudioAccessDeniedWithoutPrompt: iOS only for now. Thrown when user has previously denied the permission. iOS does not allow prompting alert dialog a second time. Users will have to go to Settings > Privacy > Microphone in order to enable audio access.

• AudioAccessRestricted: iOS only for now. Thrown when audio access is restricted and users cannot grant permission (parental control).

Example

Here is a small example flutter app displaying a full screen camera preview.

import 'package:camera/camera.dart';
import 'package:flutter/material.dart';

late List<CameraDescription> _cameras;

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  _cameras = await availableCameras();
  runApp(const CameraApp());
}

/// CameraApp is the Main Application.
class CameraApp extends StatefulWidget {
  /// Default Constructor
  const CameraApp({Key? key}) : super(key: key);

  @override
  State<CameraApp> createState() => _CameraAppState();
}

class _CameraAppState extends State<CameraApp> {
  late CameraController controller;

  @override
  void initState() {
    super.initState();
    controller = CameraController(_cameras[0], ResolutionPreset.max);
    controller.initialize().then((_) {
      if (!mounted) {
        return;
      }
      setState(() {});
    }).catchError((Object e) {
      if (e is CameraException) {
        switch (e.code) {
          case 'CameraAccessDenied':
            // Handle access errors here.
            break;
          default:
            // Handle other errors here.
            break;
        }
      }
    });
  }

  @override
  void dispose() {
    controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    if (!controller.value.isInitialized) {
      return Container();
    }
    return MaterialApp(
      home: CameraPreview(controller),
    );
  }
}

For a more elaborate usage example see here.