[go: up one dir, main page]

Play and pause a video

Playing videos is a common task in app development, and Flutter apps are no exception. To play videos, the Flutter team provides the video_player plugin. You can use the video_player plugin to play videos stored on the file system, as an asset, or from the internet.

On iOS, the video_player plugin makes use of AVPlayer to handle playback. On Android, it uses ExoPlayer.

This recipe demonstrates how to use the video_player package to stream a video from the internet with basic play and pause controls using the following steps:

  1. Add the video_player dependency.
  2. Add permissions to your app.
  3. Create and initialize a VideoPlayerController.
  4. Display the video player.
  5. Play and pause the video.

1. Add the video_player dependency

#

This recipe depends on one Flutter plugin: video_player. First, add this dependency to your project.

To add the video_player package as a dependency, run flutter pub add:

flutter pub add video_player

2. Add permissions to your app

#

Next, update your android and ios configurations to ensure that your app has the correct permissions to stream videos from the internet.

Android

#

Add the following permission to the AndroidManifest.xml file just after the <application> definition. The AndroidManifest.xml file is found at <project root>/android/app/src/main/AndroidManifest.xml.

xml
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
    <application ...>

    </application>

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

iOS

#

For iOS, add the following to the Info.plist file found at <project root>/ios/Runner/Info.plist.

xml
<key>NSAppTransportSecurity</key>
<dict>
  <key>NSAllowsArbitraryLoads</key>
  <true/>
</dict>

macOS

#

If you use network-based videos, add the com.apple.security.network.client entitlement.

Web

#

Flutter web does not support dart:io, so avoid using the VideoPlayerController.file constructor for the plugin. Using this constructor attempts to create aVideoPlayerController.file that throws an UnimplementedError.

Different web browsers might have different video-playback capabilities, such as supported formats or autoplay. Check the video_player_web package for more web-specific information.

The VideoPlayerOptions.mixWithOthers option can't be implemented in web, at least at the moment. If you use this option in web it will be silently ignored.

3. Create and initialize a VideoPlayerController

#

Now that you have the video_player plugin installed with the correct permissions, create a VideoPlayerController. The VideoPlayerController class allows you to connect to different types of videos and control playback.

Before you can play videos, you must also initialize the controller. This establishes the connection to the video and prepare the controller for playback.

To create and initialize the VideoPlayerController do the following:

  1. Create a StatefulWidget with a companion State class
  2. Add a variable to the State class to store the VideoPlayerController
  3. Add a variable to the State class to store the Future returned from VideoPlayerController.initialize
  4. Create and initialize the controller in the initState method
  5. Dispose of the controller in the dispose method
dart
class VideoPlayerScreen extends StatefulWidget {
  const VideoPlayerScreen({super.key});

  @override
  State<VideoPlayerScreen> createState() => _VideoPlayerScreenState();
}

class _VideoPlayerScreenState extends State<VideoPlayerScreen> {
  late VideoPlayerController _controller;
  late Future<void> _initializeVideoPlayerFuture;

  @override
  void initState() {
    super.initState();

    // Create and store the VideoPlayerController. The VideoPlayerController
    // offers several different constructors to play videos from assets, files,
    // or the internet.
    _controller = VideoPlayerController.networkUrl(
      Uri.parse(
        'https://flutter.github.io/assets-for-api-docs/assets/videos/butterfly.mp4',
      ),
    );

    _initializeVideoPlayerFuture = _controller.initialize();
  }

  @override
  void dispose() {
    // Ensure disposing of the VideoPlayerController to free up resources.
    _controller.dispose();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    // Complete the code in the next step.
    return Container();
  }
}

4. Display the video player

#

Now, display the video. The video_player plugin provides the VideoPlayer widget to display the video initialized by the VideoPlayerController. By default, the VideoPlayer widget takes up as much space as possible. This often isn't ideal for videos because they are meant to be displayed in a specific aspect ratio, such as 16x9 or 4x3.

Therefore, wrap the VideoPlayer widget in an AspectRatio widget to ensure that the video has the correct proportions.

Furthermore, you must display the VideoPlayer widget after the _initializeVideoPlayerFuture() completes. Use FutureBuilder to display a loading spinner until the controller finishes initializing. Note: initializing the controller does not begin playback.

dart
// Use a FutureBuilder to display a loading spinner while waiting for the
// VideoPlayerController to finish initializing.
FutureBuilder(
  future: _initializeVideoPlayerFuture,
  builder: (context, snapshot) {
    if (snapshot.connectionState == ConnectionState.done) {
      // If the VideoPlayerController has finished initialization, use
      // the data it provides to limit the aspect ratio of the video.
      return AspectRatio(
        aspectRatio: _controller.value.aspectRatio,
        // Use the VideoPlayer widget to display the video.
        child: VideoPlayer(_controller),
      );
    } else {
      // If the VideoPlayerController is still initializing, show a
      // loading spinner.
      return const Center(
        child: CircularProgressIndicator(),
      );
    }
  },
)

5. Play and pause the video

#

By default, the video starts in a paused state. To begin playback, call the play() method provided by the VideoPlayerController. To pause playback, call the pause() method.

For this example, add a FloatingActionButton to your app that displays a play or pause icon depending on the situation. When the user taps the button, play the video if it's currently paused, or pause the video if it's playing.

dart
FloatingActionButton(
  onPressed: () {
    // Wrap the play or pause in a call to `setState`. This ensures the
    // correct icon is shown.
    setState(() {
      // If the video is playing, pause it.
      if (_controller.value.isPlaying) {
        _controller.pause();
      } else {
        // If the video is paused, play it.
        _controller.play();
      }
    });
  },
  // Display the correct icon depending on the state of the player.
  child: Icon(
    _controller.value.isPlaying ? Icons.pause : Icons.play_arrow,
  ),
)

Complete example

#
import 'dart:async';

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

void main() => runApp(const VideoPlayerApp());

class VideoPlayerApp extends StatelessWidget {
  const VideoPlayerApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: 'Video Player Demo',
      home: VideoPlayerScreen(),
    );
  }
}

class VideoPlayerScreen extends StatefulWidget {
  const VideoPlayerScreen({super.key});

  @override
  State<VideoPlayerScreen> createState() => _VideoPlayerScreenState();
}

class _VideoPlayerScreenState extends State<VideoPlayerScreen> {
  late VideoPlayerController _controller;
  late Future<void> _initializeVideoPlayerFuture;

  @override
  void initState() {
    super.initState();

    // Create and store the VideoPlayerController. The VideoPlayerController
    // offers several different constructors to play videos from assets, files,
    // or the internet.
    _controller = VideoPlayerController.networkUrl(
      Uri.parse(
        'https://flutter.github.io/assets-for-api-docs/assets/videos/butterfly.mp4',
      ),
    );

    // Initialize the controller and store the Future for later use.
    _initializeVideoPlayerFuture = _controller.initialize();

    // Use the controller to loop the video.
    _controller.setLooping(true);
  }

  @override
  void dispose() {
    // Ensure disposing of the VideoPlayerController to free up resources.
    _controller.dispose();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Butterfly Video'),
      ),
      // Use a FutureBuilder to display a loading spinner while waiting for the
      // VideoPlayerController to finish initializing.
      body: FutureBuilder(
        future: _initializeVideoPlayerFuture,
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.done) {
            // If the VideoPlayerController has finished initialization, use
            // the data it provides to limit the aspect ratio of the video.
            return AspectRatio(
              aspectRatio: _controller.value.aspectRatio,
              // Use the VideoPlayer widget to display the video.
              child: VideoPlayer(_controller),
            );
          } else {
            // If the VideoPlayerController is still initializing, show a
            // loading spinner.
            return const Center(
              child: CircularProgressIndicator(),
            );
          }
        },
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          // Wrap the play or pause in a call to `setState`. This ensures the
          // correct icon is shown.
          setState(() {
            // If the video is playing, pause it.
            if (_controller.value.isPlaying) {
              _controller.pause();
            } else {
              // If the video is paused, play it.
              _controller.play();
            }
          });
        },
        // Display the correct icon depending on the state of the player.
        child: Icon(
          _controller.value.isPlaying ? Icons.pause : Icons.play_arrow,
        ),
      ),
    );
  }
}