csells/waveform_recorder

The waveform_recorder package provides a widget to show a waveform as an audio stream is being recorded in the style of recent AI chat packages.

Screenshot of waveform_recorder in action

Setup

For this package to work, you'll need to set up the underlying record package according to the setup and permission instructions.

Usage

The main entry point for this package is the WaveformRecorder widget, which requires an instance of the WaveformRecorderController to start/stop recording. Here's an example of using the recorder to record audio and then allowing the user to play it back:

import 'dart:async';

import 'package:audioplayers/audioplayers.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:gap/gap.dart';
import 'package:waveform_recorder/waveform_recorder.dart';

void main() => runApp(const MyApp());

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

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

class _MyAppState extends State<MyApp> {
  final _textController = TextEditingController();
  final _waveController = WaveformRecorderController();

  @override
  void dispose() {
    _textController.dispose();
    _waveController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => MaterialApp(
        home: Scaffold(
          appBar: AppBar(title: const Text('WaveForm Example')),
          body: ListenableBuilder(
            listenable: _waveController,
            builder: (context, _) => Column(
              children: [
                Expanded(
                  child: Center(
                    child: OutlinedButton(
                      onPressed: !_waveController.isRecording &&
                              _waveController.file != null
                          ? _playRecording
                          : null,
                      child: const Text('Play'),
                    ),
                  ),
                ),
                Padding(
                  padding: const EdgeInsets.all(16),
                  child: Row(
                    children: [
                      Expanded(
                        child: DecoratedBox(
                          decoration: BoxDecoration(
                            border: Border.all(color: Colors.grey),
                            borderRadius: BorderRadius.circular(8),
                          ),
                          child: _waveController.isRecording
                              ? WaveformRecorder(
                                  height: 48,
                                  controller: _waveController,
                                  onRecordingStopped: _onRecordingStopped,
                                )
                              : TextField(
                                  controller: _textController,
                                  maxLines: 1,
                                  decoration: const InputDecoration(
                                    border: InputBorder.none,
                                    contentPadding: EdgeInsets.symmetric(
                                      horizontal: 8,
                                    ),
                                  ),
                                ),
                        ),
                      ),
                      const Gap(8),
                      IconButton(
                        icon: Icon(
                          _waveController.isRecording ? Icons.stop : Icons.mic,
                        ),
                        onPressed: _toggleRecording,
                      ),
                    ],
                  ),
                ),
              ],
            ),
          ),
        ),
      );

  Future<void> _toggleRecording() => switch (_waveController.isRecording) {
        true => _waveController.stopRecording(),
        false => _waveController.startRecording(),
      };

  Future<void> _onRecordingStopped() async {
    final file = _waveController.file;
    if (file == null) return;

    _textController.text = ''
        '${file.name}: '
        '${_waveController.length.inMilliseconds / 1000} seconds';

    debugPrint('XFile properties:');
    debugPrint('  path: ${file.path}');
    debugPrint('  name: ${file.name}');
    debugPrint('  mimeType: ${file.mimeType}');
  }

  Future<void> _playRecording() async {
    final file = _waveController.file;
    if (file == null) return;
    final source = kIsWeb ? UrlSource(file.path) : DeviceFileSource(file.path);
    await AudioPlayer().play(source);
  }
}

Usage Considerations

For all platforms except the web, the output of a record operation is a file on your hard drive; it's your app's responsibility to remove this temp file when it's done with it. When executing on the web, the file (an instance of the XFile type from the cross_file package) of the recorded audio will contain a path to a blob URL but otherwise, it will be a file in the file system. You can get the path to that file from WaveformRecorderController.file.path, e.g.

  Future<void> _deleteRecording() async {
    final file = _waveController.file;
    if (file == null) return;
    if (!kIsWeb) await File(file.path).delete();
  }

Feedback

Your feedback via issues or PRs is welcome!