How to playback an .mp3 file in a Flutter app?

Question

I have written a Dart web app that retrieves .mp3 files from a server and plays them back; I am trying to write a mobile version using Flutter. I know dart:web_audio is the main option for a web app, but Flutter can't find it in my SDK. I know it's there because I can compile the following to Javascript:

import 'dart:html';
import 'dart:convert';
import 'dart:web_audio';
AudioContext audioContext;

main() async {
  audioContext = new AudioContext();
  var ul = (querySelector('#songs') as UListElement);
  var signal = await HttpRequest.getString('http://10.0.0.6:8000/api/filelist');
 //  Map json = JSON.decode(signal);
 //  for (Map file in json['songs']) {
   print("signal: $signal");
   Map json = JSON.decode(signal);
   for (Map file in json['songs']) {
     var li = new LIElement()
       ..appendText(file['title']);
     var button = new ButtonElement();
     button.setAttribute("id", "#${file['file']}");
     button.appendText("Play");

     li.append(button);
     new Song(button, file['file']);
     ul.append(li);

  }

}

class Song {
  ButtonElement button;
  bool _playing = false;
  // AudioContext _audioContext;
  AudioBufferSourceNode _source;
  String title;

  Song(this.button, this.title) {

    button..onClick.listen((e) => _toggle());
  }

  _toggle() {
    _playing = !_playing;
    _playing ? _start() : _stop();
  }

  _start() {
    return HttpRequest
         .request("http://10.0.0.6:8000/music/$title", responseType: "arraybuffer")
         .then((HttpRequest httpRequest) {
            return audioContext
              .decodeAudioData(httpRequest.response)
         .then((AudioBuffer buffer) {
              _source = audioContext.createBufferSource();
              _source.buffer = buffer;
              _source.connectNode(audioContext.destination);
              _source.start(0);
              button.text = "Stop";
              _source.onEnded.listen((e){
                 _playing = false;
                 button.text = "Play";
          });
       });
    });
  }

  _stop() {
     _source.stop(0);
     button.text = "Play";
  }
} 

How would I rewrite the dart:web_audio parts of my code for a Flutter app? Can Flutter access MediaPlayer? And if so, how would I refer to it in pubspec.yaml?

Solution 1

As raju-bitter noted above, Flutter used to provide some built-in audio wrappers in its core engine but those have since been removed: https://github.com/flutter/flutter/issues/1364.

Flutter-using Apps are just iOS or Android apps, and thus it is possible to do anything the underlying iOS/Android can do via Flutter using some Java or Obj-C code in the hello_services model (https://github.com/flutter/flutter/tree/master/examples/hello_services). This model is documented at https://flutter.io/platform-services. It's not nearly as easy as we'd like it to be yet. Many improvements to come soon.

Solution 2

I know its 4 years late, but i have found audioplayers package which can be used as the following

import 'package:audioplayers/audio_cache.dart';
import 'package:audioplayers/audioplayers.dart';

//Call this function from an event
void playRemoteFile() {
    AudioPlayer player = new AudioPlayer();
    player.play("https://luan.xyz/files/audio/ambient_c_motion.mp3");
}