Play asset wav file

[goranesine]

Hello, can you give us an example of how to play asset file in Flutter framework?

[goranesine]

I manage to play the asset audio file but just one time. When I first-time call outputNode.device.start() the sound is playing. On the second call - nothing ? Here is the code:

final decoder = MabAudioDecoder( dataSource: AudioFileDataSource(file: accentFile, mode: FileMode.read), outputFormat: format); final wavNode = DecoderNode(decoder: decoder); graphNode.connect(wavNode.outputBus, outputNode.inputBus); graphNode.connectEndpoint(outputNode.outputBus); outputTask.start();

outputNode.device.start()

[potatosalad775]

I believe you cannot start outputNode.device again since it's already running.

Can you be more specific about what are you trying to achieve?

[goranesine]

I just want to play one sample from the asset multiple time. On the press of a button, I call outputNode.device.start(); The sample played nice the first time. Then I call outputNode.device.stop(); When I call outputNode.device.start(); again nothing happens. After some testing, I find that outputNode.device.availableReadFrames are empty after the first call.

[SKKbySSK]

Sorry for my late response. Can you provide your device info (OS, version, model name) and minimal reproducible code?

I find that outputNode.device.availableReadFrames are empty after the first call.

It seems that the device's internal audio buffer is not filled out correctly. Have you restart the outputTask when the second press of a button?

[goranesine]

`import 'dart:io';

import 'package:flutter/material.dart'; import 'package:flutter/services.dart'; import 'package:flutter_coast_audio_miniaudio/flutter_coast_audio_miniaudio.dart'; import 'package:path_provider/path_provider.dart';

void main() { MabLibrary.initialize(); MabDeviceContext.enableSharedInstance(backends: [ MabBackend.aaudio, MabBackend.coreAudio, ]); runApp(const MyApp()); }

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

@override State createState() => _MyAppState(); }

class _MyAppState extends State { final format = const AudioFormat(sampleRate: 48000, channels: 2); late final MabAudioPlayer audioPlayer; late final MabAudioDecoder decoder; late final DecoderNode wavNode; late AudioFileDataSource dataSource; late final outputNode = MabPlaybackDeviceNode( device: MabPlaybackDevice( context: MabDeviceContext.sharedInstance, format: format, bufferFrameSize: 4096, ), ); final graphNode = GraphNode();

late final outputTask = AudioTask( clock: AudioIntervalClock(const Duration(milliseconds: 16)), readFrameSize: 4096, endpoint: graphNode.outputBus, format: format, );

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

void initAccentFile() async { await copyAssetToDir("accent.wav").then((value) { dataSource = AudioFileDataSource(file: value, mode: FileMode.read); decoder = MabAudioDecoder(dataSource: dataSource, outputFormat: format); wavNode = DecoderNode(decoder: decoder);

  graphNode.connect(wavNode.outputBus, outputNode.inputBus);
  graphNode.connectEndpoint(outputNode.outputBus);
  outputTask.start();
});

}

Future copyAssetToDir(String path) async { Directory tempDir = await getTemporaryDirectory(); String tempPath = tempDir.path; var filePath = "$tempPath/$path"; var file = File(filePath); if (file.existsSync()) { return file; } else { final byteData = await rootBundle.load('assets/$path'); final buffer = byteData.buffer; await file.create(recursive: true); return file.writeAsBytes( buffer.asUint8List(byteData.offsetInBytes, byteData.lengthInBytes)); } }

@override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( appBar: AppBar( title: const Text('Plugin example app'), ), body: Center( child: Row( mainAxisAlignment: MainAxisAlignment.center, children: [ ElevatedButton( onPressed: () => outputNode.device.start(), child: const Text('Start'), ), const SizedBox(width: 12), ElevatedButton( onPressed: () => outputNode.device.stop(), child: const Text('Stop'), ),

        ],
      ),
    ),
  ),
);

} }

Is this a wrong approach ?`

[SKKbySSK]

You need to set decoder's cursor to 0 when you press the start button.

decoder.cursorInFrames = 0;
outputNode.device.start();

[goranesine]

The solution works, thanks.