Reviens 🎛️ — Perfect Loop Maker

Reviens is a small web application for creating perfectly loopable audio clips from any audio file. It provides tempo (BPM) detection, pitch detection, selection tools (snap to beat / zero crossing), enhanced crossfade options and a straightforward WAV export workflow.

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🔧 Key Features

• Drag-and-drop or file picker for loading audio (standard formats supported)
• Waveform visualization with beat/measure navigation
• Automatic BPM and pitch detection
• Quick length presets (1 / 2 / 4 / 8 / 16 / 32 beats)
• Advanced tools: crossfade types, click reduction, snap to beat / zero crossing
• Automatic loop suggestion (FIND LOOPS)
• WAV export with enriched filename metadata (pitch, bpm, length, crossfade, timestamp)

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🚀 How to Use

1. Open the app in your browser:

   • Open the file directly:

     reviens/reviens.html

   • Or run a local static server (recommended) from the repository root:

     # from the project root
     python3 -m http.server 8000
     # then open http://localhost:8000/reviens/reviens.html

2. Drag and drop an audio file or click the upload area to choose a file.

3. Use the waveform to place the loop start point, or click FIND LOOPS to let the app suggest segments.

4. Adjust loop length (1 / 2 / 4 beats, ...), position and advanced settings (crossfade, click reduction, snap).

5. Click EXPORT to generate a WAV file. The export applies a crossfade to create seamless loops.

Tip: For best results, enable “Snap to beat” and choose durations that match whole musical measures (1 bar, 2 bars, ...).

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🗂️ Project Structure

• reviens/reviens.html — main UI
• reviens/REVIENS/ — scripts and styles (e.g. main.js, loop-analyzer.js, export-manager.js, etc.)

Export logic is implemented in REVIENS/export-manager.js: it produces a 16-bit WAV and builds a descriptive filename including pitch, bpm, length and timestamp.

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🛠 Development & Debugging

• No build step required — the app is static. Edit files in REVIENS/ directly.

• To test locally:

  python3 -m http.server 8000
  # or use a static dev server (live-server, http-server, etc.)

• Check your browser console for logs and errors (audio detection, export, permission issues).

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✅ Export Details

• Format: WAV 16-bit

• The exporter will try to use the File System Access API when available, otherwise it will fall back to a classic download.

• Example generated filename:

  reviens_C4_120bpm_1bar_2_0s_cos_CR_440hz_20260110_120000.wav

  (contains detected note, bpm, musical length, duration, crossfade type, click reduction flag, detected frequency and timestamp)

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Contributing

• Report issues or suggest improvements via the repository's issue tracker.
• Fork & PR: describe your change and include tests or a demo when applicable.

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License

No explicit license is provided in this repository. Add a LICENSE file (e.g. MIT, Apache-2.0) if you want to specify terms.

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Credits

• Associated with TOPLAP Strasbourg (see link in the app UI)

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Contact

For questions or technical discussions, open an issue in the repository or contact the project author.

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Notes & future ideas:

• Multi-format export (MP3/OGG) via a backend or ffmpeg
• Improve tempo detection for polyrythmic music
• Add a small envelope editor and advanced fade shaper

Thanks — have fun making loops! 🔁🎶