Code of main.dart for Working with Audio

import 'dart:async';

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

void main() {
  runApp(const MaterialApp(home: _SimpleExampleApp()));
}

class _SimpleExampleApp extends StatefulWidget {
  const _SimpleExampleApp();

  @override
  _SimpleExampleAppState createState() => _SimpleExampleAppState();
}

class _SimpleExampleAppState extends State<_SimpleExampleApp> {
  late AudioPlayer player = AudioPlayer();

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

    // Create the audio player.
    player = AudioPlayer();

    // Set the release mode to keep the source after playback has completed.
    player.setReleaseMode(ReleaseMode.stop);

    // Start the player as soon as the app is displayed.
    WidgetsBinding.instance.addPostFrameCallback((_) async {
      await player.setSource(AssetSource('iphone.mp3'));
      await player.resume();
    });
  }

  @override
  void dispose() {
    // Release all sources and dispose the player.
    player.dispose();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Simple Player'),
      ),
      body: PlayerWidget(player: player),
    );
  }
}

// The PlayerWidget is a copy of "/lib/components/player_widget.dart".
//#region PlayerWidget

class PlayerWidget extends StatefulWidget {
  final AudioPlayer player;

  const PlayerWidget({
    required this.player,
    super.key,
  });

  @override
  State createState() {
    return _PlayerWidgetState();
  }
}

class _PlayerWidgetState extends State {
  PlayerState? _playerState;
  Duration? _duration;
  Duration? _position;

  StreamSubscription? _durationSubscription;
  StreamSubscription? _positionSubscription;
  StreamSubscription? _playerCompleteSubscription;
  StreamSubscription? _playerStateChangeSubscription;

  bool get _isPlaying => _playerState == PlayerState.playing;

  bool get _isPaused => _playerState == PlayerState.paused;

  String get _durationText => _duration?.toString().split('.').first ?? '';

  String get _positionText => _position?.toString().split('.').first ?? '';

  AudioPlayer get player => widget.player;

  @override
  void initState() {
    super.initState();
    // Use initial values from player
    _playerState = player.state;
    player.getDuration().then(
          (value) => setState(() {
        _duration = value;
      }),
    );
    player.getCurrentPosition().then(
          (value) => setState(() {
        _position = value;
      }),
    );
    _initStreams();
  }

  @override
  void setState(VoidCallback fn) {
    // Subscriptions only can be closed asynchronously,
    // therefore events can occur after widget has been disposed.
    if (mounted) {
      super.setState(fn);
    }
  }

  @override
  void dispose() {
    _durationSubscription?.cancel();
    _positionSubscription?.cancel();
    _playerCompleteSubscription?.cancel();
    _playerStateChangeSubscription?.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final color = Theme.of(context).primaryColor;
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            IconButton(
              key: const Key('play_button'),
              onPressed: _isPlaying ? null : _play,
              iconSize: 48.0,
              icon: const Icon(Icons.play_arrow),
              color: color,
            ),
            IconButton(
              key: const Key('pause_button'),
              onPressed: _isPlaying ? _pause : null,
              iconSize: 48.0,
              icon: const Icon(Icons.pause),
              color: color,
            ),
            IconButton(
              key: const Key('stop_button'),
              onPressed: _isPlaying || _isPaused ? _stop : null,
              iconSize: 48.0,
              icon: const Icon(Icons.stop),
              color: color,
            ),
          ],
        ),
        Slider(
          onChanged: (value) {
            final duration = _duration;
            if (duration == null) {
              return;
            }
            final position = value * duration.inMilliseconds;
            player.seek(Duration(milliseconds: position.round()));
          },
          value: (_position != null &&
              _duration != null &&
              _position!.inMilliseconds > 0 &&
              _position!.inMilliseconds < _duration!.inMilliseconds)
              ? _position!.inMilliseconds / _duration!.inMilliseconds
              : 0.0,
        ),
        Text(
          _position != null
              ? '$_positionText / $_durationText'
              : _duration != null
              ? _durationText
              : '',
          style: const TextStyle(fontSize: 16.0),
        ),
      ],
    );
  }

  void _initStreams() {
    _durationSubscription = player.onDurationChanged.listen((duration) {
      setState(() => _duration = duration);
    });

    _positionSubscription = player.onPositionChanged.listen(
          (p) => setState(() => _position = p),
    );

    _playerCompleteSubscription = player.onPlayerComplete.listen((event) {
      setState(() {
        _playerState = PlayerState.stopped;
        _position = Duration.zero;
      });
    });

    _playerStateChangeSubscription =
        player.onPlayerStateChanged.listen((state) {
          setState(() {
            _playerState = state;
          });
        });
  }

  Future _play() async {
    await player.resume();
    setState(() => _playerState = PlayerState.playing);
  }

  Future _pause() async {
    await player.pause();
    setState(() => _playerState = PlayerState.paused);
  }

  Future _stop() async {
    await player.stop();
    setState(() {
      _playerState = PlayerState.stopped;
      _position = Duration.zero;
    });
  }
}

								   

Code of main.dart for Working with Video

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 createState() => _VideoPlayerScreenState();
}

class _VideoPlayerScreenState extends State {
  late VideoPlayerController _controller;
  late Future _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,
        ),
      ),
    );
  }
}