WavFFT-Qt

A Qt-based desktop application for visualizing WAV audio files in time and frequency domains using FFTW

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📋 Overview

WavFFT-Qt is a desktop audio analyzer that allows you to open WAV files and visualize both the time-domain waveform and frequency-domain FFT spectrum. The application supports interactive zooming and panning, along with audio processing features like upsampling, downsampling, and segment saving.

Features

• ✅ Open and load 16-bit PCM WAV files (mono or stereo)
• ✅ Automatic stereo-to-mono conversion
• ✅ Real-time waveform visualization (time domain)
• ✅ Real-time FFT magnitude spectrum (frequency domain)
• ✅ Interactive plot controls (zoom, pan, drag)
• ✅ Downsample and Upsample audio
• ✅ Save audio segments
• ✅ Playback speed control (Fast / Slow)

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🛠️ Tech Stack

• Language: C++
• GUI Framework: Qt 5/6 (Widgets)
• Plotting: QCustomPlot
• FFT Library: FFTW 3.3.5 (64-bit)

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📦 Prerequisites

Before building the project, ensure you have the following installed:

• Qt SDK (5.x or 6.x) with Qt Creator
• FFTW 3.3.5 DLL (64-bit) – Download here
• QCustomPlot library (usually included or as a separate .h/.cpp)
• MinGW-w64 or MSVC compiler (depending on your Qt setup)

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🚀 Setup & Build

1. Clone the repository

git clone https://github.com/siinnnaaa/WavFFT-Qt.git
cd WavFFT-Qt

2. Download and install FFTW

• Download FFTW 3.3.5 precompiled DLL (64-bit) from the official site
• Extract and place fftw3.dll in your project directory or system PATH
• Update the .pro file to link against libfftw3-3.dll or fftw3.lib

3. Open the project in Qt Creator

open FFTW_PRJ.pro

or simply double-click FFTW_PRJ.pro

4. Build and run

• Click Build → Build Project
• Click Run to launch the application

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📂 Project Structure

WavFFT-Qt/ ├── src/ │ ├── main.cpp # Entry point │ ├── mainwindow.cpp # Main logic and signal processing │ ├── mainwindow.h # Header file │ └── mainwindow.ui # Qt Designer UI file ├── FFTW_PRJ.pro # Qt project file ├── docs/ │ └── screenshots/ # Application screenshots ├── README.md ├── LICENSE └── .gitignore

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🎨 UI Components

Main Window: Show WAV و FFT

Widget	Description
wavePlot	Time-domain waveform plot X: Time (s), Y: Amplitude
fftPlot	Frequency-domain FFT magnitude plot X: Frequency (Hz), Y: Magnitude
openBtn	Open WAV file dialog
btnDown	Downsample audio
btnUp	Upsample audio
btnSave	Save selected segment
pbFast	Increase playback speed
pbSlow	Decrease playback speed
infoLabel	Displays file name, sample rate, and sample count

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🔧 How It Works

1. Open WAV File: User selects a 16-bit PCM WAV file
2. Load & Convert: File is loaded, stereo is converted to mono
3. Plot Waveform: Time-domain signal is plotted on wavePlot
4. Compute FFT: FFTW computes the FFT of the audio signal
5. Plot Spectrum: Magnitude spectrum is plotted on fftPlot
6. Interactive Controls: User can zoom, pan, resample, or save segments

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📸 Screenshots

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📄 License

This project is licensed under the MIT License – see the LICENSE file for details.

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🙏 Acknowledgments

• FFTW – Fast Fourier Transform library
• QCustomPlot – Qt plotting library
• Qt Project

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📧 Contact

For questions or suggestions, feel free to open an issue or reach out!

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Made with ❤️ using Qt + FFTW + C++