Creating Dynamic Audio Waveforms in Flutter

Understanding Audio Waveforms

Audio waveforms are dynamic visual representations of sound waves. The x-axis represents time, and the y-axis represents amplitude. Higher waves indicate louder sounds, while lower or flatter waves represent softer areas in the audio. By displaying waveforms, users can adjust their volume accordingly, ensuring that their spoken words are captured clearly by the microphone.

Setting Up Your Flutter App

To create waveforms in Flutter, you’ll need to add the necessary dependencies and permissions. First, import the audio_waveforms package in your main.dart file:

import 'package:audio_waveforms/audio_waveforms.dart';

Then, add the permission to record audio to your Android manifest:

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

Creating the Waveforms

To create waveforms, you’ll need to use the AudioWaveforms widget. Before you can do this, you’ll need to create a RecordController that will be passed to the AudioWaveforms widget. Initialize the controller by calling the initRecorder method, and then use it to record audio and display the waveform:

final recordController = RecordController();
await recordController.initRecorder();

// Create the AudioWaveforms widget
AudioWaveforms(controller: recordController);

Customizing the Waveforms

You can customize the waveforms by changing the style of the waves, including aspects like:

• Size
• Wave style
• Color
• Padding
• Margin

You can also apply color gradients to the waves.

Playing Audio

To play audio files and generate waveforms for them, you’ll need to create a PlayerController instead of a RecordController. Use the AudioFileWaveforms widget instead of AudioWaveforms, and pass the player controller to it. Provide the path of the audio file to the controller, and then start and stop the player using the controller’s methods:

final playerController = PlayerController();
playerController.setFilePath('path/to/audio/file.mp3');
playerController.start();
playerController.stop();

// Create the AudioFileWaveforms widget
AudioFileWaveforms(controller: playerController);

Disposing the Controllers

Finally, don’t forget to dispose of the controllers you used to record and play audio. This is important to prevent memory leaks and ensure that your app runs smoothly:

@override
void dispose() {
  recordController.dispose();
  playerController.dispose();
  super.dispose();
}