camera 0.8.0-nullsafety

A Flutter plugin for getting information about and controlling the camera on Android and iOS. Supports previewing the camera feed, capturing images, capturing video, and streaming image buffers to dart.

Camera Plugin

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

Note: This plugin is still under development, and some APIs might not be available yet. We are working on a refactor which can be followed here: issue

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

iOS 10.0 of higher is needed to use the camera plugin. If compiling for any version lower than 10.0 make sure to check the iOS version before using the camera plugin. For example, using the device_info plugin.

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.

Or in text format add the key:

<key>NSCameraUsageDescription</key>
<string>Can I use the camera please?</string>
<key>NSMicrophoneUsageDescription</key>
<string>Can I use the mic please?</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.

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) {
    // App state changed before we got the chance to initialize.
    if (controller == null || !controller.value.isInitialized) {
      return;
    }
    if (state == AppLifecycleState.inactive) {
      controller?.dispose();
    } else if (state == AppLifecycleState.resumed) {
      if (controller != null) {
        onNewCameraSelected(controller.description);
      }
    }
  }

Example

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

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

List<CameraDescription> cameras;

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  cameras = await availableCameras();
  runApp(CameraApp());
}

class CameraApp extends StatefulWidget {
  @override
  _CameraAppState createState() => _CameraAppState();
}

class _CameraAppState extends State<CameraApp> {
  CameraController controller;

  @override
  void initState() {
    super.initState();
    controller = CameraController(cameras[0], ResolutionPreset.medium);
    controller.initialize().then((_) {
      if (!mounted) {
        return;
      }
      setState(() {});
    });
  }

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

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

For a more elaborate usage example see here.

Note: This plugin is still under development, and some APIs might not be available yet. Feedback welcome and Pull Requests are most welcome!