flutter_sound

This plugin provides simple recorder and player functionalities for both `android` and `ios` platforms. This only supports default file extension for each platform. This plugin handles file from remote url. This plugin can handle playback stream from native (To sync exact time with bridging).

Free Read

Medium Blog

Getting Started

For help getting started with Flutter, view our online documentation.

Install

Add flutter_sound as a dependency in pubspec.yaml For help on adding as a dependency, view the documentation.

Post Installation

On iOS you need to add a usage description to info.plist:

<key>NSMicrophoneUsageDescription</key>
<string>This sample uses the microphone to record your speech and convert it to text.</string>
<key>UIBackgroundModes</key>
<array>
	<string>audio</string>
</array>

On Android you need to add a permission to AndroidManifest.xml:

<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Methods

Func	Param	Return	Description
setSubscriptionDuration	double sec	String message	Set subscription timer in seconds. Default is 0.01 if not using this method.
startRecorder	String uri, int sampleRate, int numChannels, t_CODEC codec	String uri	Start recording. This will return uri used.
stopRecorder		String message	Stop recording.
startPlayer	String uri	String message	Start playing.
startPlayerFromBuffer	Uint8List dataBuffer	String message	Start playing.
stopPlayer		String message	Stop playing.
pausePlayer		String message	Pause playing.
resumePlayer		String message	Resume playing.
seekToPlayer	int milliSecs position to goTo	String message	Seek audio to selected position in seconds. Parameter should be less than audio duration to correctly placed.

Subscriptions

Subscription	Return	Description
onRecorderStateChanged	<RecordStatus>	Able to listen to subscription when recorder starts.
onPlayerStateChanged	<PlayStatus>	Able to listen to subscription when player starts.

Default uri path

When uri path is not set during the function call in startRecorder or startPlayer, they are saved in below path depending on the platform.

• Default path for android
  • Library/Caches/sound.aac.
• Default path for ios
  • sound.aac.

Usage

Creating instance.

In your view/page/dialog widget's State class, create an instance of FlutterSound.

FlutterSound flutterSound = new FlutterSound();

Starting recorder with listener.

Future<String> result = await flutterSound.startRecorder(null);

result.then(path) {
	print('startRecorder: $path');

	_recorderSubscription = flutterSound.onRecorderStateChanged.listen((e) {
	DateTime date = new DateTime.fromMillisecondsSinceEpoch(e.currentPosition.toInt());
	String txt = DateFormat('mm:ss:SS', 'en_US').format(date);
	});
}

If you want to take your own path specify it like below.

String path = await flutterSound.startRecorder(Platform.isIOS ? 'ios.aac' : 'android.aac');

Actually on iOS, you can choose from two encoders :

• AAC (this is the default)
• CAF/OPUS

To encode with OPUS you do the following :

await flutterSound.startRecorder(null, codec: t_CODEC.CODEC_CAF_OPUS,)

Recently, Apple added a support for encoding with the standard OPUS codec. Unfortunetly, Apple encapsulates its data in its own proprietary envelope : CAF. This is really stupid, this is Apple

On Android the OPUS codec is not yet supported by flutter_sound.

Stop recorder

Future<String> result = await flutterSound.stopRecorder();

result.then(value) {
	print('stopRecorder: $value');

	if (_recorderSubscription != null) {
		_recorderSubscription.cancel();
		_recorderSubscription = null;
	}
}

You MUST ensure that the recorder has been stopped when your widget is detached from the ui. Overload your widget's dispose() method to stop the recorder when your widget is disposed.

@override
void dispose() {
	flutterSound.stopRecorder();
	super.dispose();
}

Start player

• To start playback of a record from a URL call startPlayer.
• To start playback of a record from a memory buffer call startPlayerFromBuffer

You must wait for the return value to complete before attempting to add any listeners to ensure that the player has fully initialised.

Future<String> result = await flutterSound.startPlayer(null);

result.then(path) {
	print('startPlayer: $path');

	_playerSubscription = flutterSound.onPlayerStateChanged.listen((e) {
		if (e != null) {
			DateTime date = new DateTime.fromMillisecondsSinceEpoch(e.currentPosition.toInt());
			String txt = DateFormat('mm:ss:SS', 'en_US').format(date);
			this.setState(() {
				this._isPlaying = true;
				this._playerTxt = txt.substring(0, 8);
			});
		}
	});
}

Stop player

Future<String> result = await flutterSound.stopPlayer();

result.then(value) {
	print('stopPlayer: $result');
	if (_playerSubscription != null) {
		_playerSubscription.cancel();
		_playerSubscription = null;
	}
}

You MUST ensure that the player has been stopped when your widget is detached from the ui. Overload your widget's dispose() method to stop the player when your widget is disposed.

@override
void dispose() {
	flutterSound.stopPlayer();
	super.dispose();
}

Pause player

Future<String> result = await flutterSound.pausePlayer();

Resume player

Future<String> result = await flutterSound.resumePlayer();

Seek player

To seek to a new location the player must already be playing.

String Future<result> = await flutterSound.seekToPlayer(miliSecs);

Setting subscription duration (Optional). 0.01 is default value when not set.

/// 0.01 is default
flutterSound.setSubscriptionDuration(0.01);

Setting volume.

/// 1.0 is default
/// Currently, volume can be changed when player is running. Try manage this right after player starts.
String path = await flutterSound.startPlayer(null);
await flutterSound.setVolume(0.1);

Using the amplitude meter

The amplitude meter allows displaying a basic representation of the input sound. When enabled, it returns values ranging 0-120dB.

//// By default this option is disabled, you can enable it by calling
setDbLevelEnabled(true);

//// You can tweak the frequency of updates by calling this function (unit is seconds)
updateDbPeakProgress(0.8);

//// You need to subscribe in order to receive the value updates
_dbPeakSubscription = flutterSound.onRecorderDbPeakChanged.listen((value) {
  setState(() {
    this._dbLevel = value;
  });
});

TODO

• Seeking example in Example project
• Volume Control
• Sync timing for recorder callback handler

DEBUG

When you face below error,

* What went wrong:
A problem occurred evaluating project ':app'.
> versionCode not found. Define flutter.versionCode in the local.properties file.

Please add below to your example/android/local.properties file.

flutter.versionName=1.0.0
flutter.versionCode=1
flutter.buildMode=debug

Help Maintenance

I've been maintaining quite many repos these days and burning out slowly. If you could help me cheer up, buying me a cup of coffee will make my life really happy and get much energy out of it.