Voice_Morph

Description:

A Flutter-Based Local Audio Transformer — this project allows users to perform audio transformation locally on their device, likely capturing, modifying, and playing back audio in real-time.

---

ANDROID

Android.mp4

IOS

Iphone.1.mp4

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Folder Structure

• lib/
  • main.dart
  • bloc/
    • voice_bloc.dart
  • features/
    • voice_visualizer/
      • ui/
        • voice_visualizer_screen.dart
      • widgets/
        • button.dart
  • hooks/
    • use_mic_permission.dart
  • services/
    • audio_capture_service.dart
    • transform_service.dart
  • shared/
    • constants/
      • colors.dart
    • utils/
      • audio_utils.dart
      • download_audio_file.dart
    • widgets/
      • blob_painter.dart
      • waveform_painter.dart

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Package Used:

• cupertino_icons: ^1.0.8
• permission_handler: ^11.4.0
• flutter_audio_capture: ^1.1.11
• path_provider: ^2.1.5
• flutter_hooks: ^0.21.2
• flutter_bloc: ^9.1.1
• flutter_spinkit: ^5.2.1
• record: ^6.0.0
• ffmpeg_kit_flutter_new: ^2.0.0
• share_plus: ^11.0.0
• audio_waveforms: ^1.3.0
• device_info_plus: ^11.3.0 android_intent_plus: ^5.3.0

---

Modules Overview

Module	Responsibility
AudioBloc	Manages recording state & waveform updates
AudioCaptureService	Interfaces with microphone input using record
WaveformPainter	Renders real-time waveform visuals
TransformService	Applies FFmpeg audio effects (pitch/speed)
handleTransformedAudioShareOrDownload	Exports audio to Downloads (Android) or shares (iOS)
useAudioPermission	Requests microphone permission on widget load

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🔁 Data Flow

[User taps Record]
   ↓
AudioBloc.startRecording()
   ↓
AudioCaptureService.start() starts microphone & amplitude listener
   ↓
Amplitude values every 100ms → normalizeAmplitude()
   ↓
Emit AudioUpdated(amplitude, waveform)
   ↓
WaveformPainter renders live waveform

[User taps Stop]
   ↓
AudioBloc.stopRecording()

[User selects effect + taps Transform]
   ↓
TransformService.transformAac(path, effect)
   ↓
Output file stored → available for playback/export

[User taps Export]
   ↓
iOS → Share via share_plus
Android → Save to Downloads folder

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Audio Bloc

Future<void> startRecording(String path)

• Starts microphone using AudioCaptureService
• Captures amplitude every 100ms
• Emits AudioUpdated with amplitude & waveform
• Maintains only the last 60 values

AudioCaptureService

AudioRecorder _recorder = AudioRecorder();

Uses record package to:

• Start/stop recording to .aac
• Subscribe to amplitude updates via stream

WaveformPainter

• Paints bars for each amplitude on a Canvas
• Bar height proportional to amplitude
• Adjusts spacing and strokeWidth dynamically

TransformService

transformAac({ inputPath, effect })

• Uses FFmpegKit to apply transformations:

Effect	Filter Applied
male	asetrate=44100*0.8,atempo=1.25
female	asetrate=44100*1.2,atempo=0.83
child	asetrate=44100*1.4,atempo=0.71
robot	afftfilt=real='hypot(re,im)':imag='0'
deep	asetrate=44100*0.6,atempo=1.66
high_pitch	asetrate=44100*1.5,atempo=0.67

• Outputs an .aac file in the temporary directory

File Export

handleTransformedAudioShareOrDownload(path) iOS:

• Shares via share_plus

Android:

• Requests appropriate storage permissions (based on SDK version)
• Copies file to /storage/emulated/0/Download

Permission Handling

useAudioPermission()

• Hook-based mic permission request
• On permanent denial, opens app settings