WaveCleaver

Extract individual audio cycles from WAV files and export them as synthesizer wavetables.

Features

• Automatic pitch detection (two-pass F0 estimation with octave-jump suppression)
• Zero-crossing-guided cycle detection for clean loop points
• RMSE-based frame candidate selection to pick perceptually distinct cycles
• Interactive waveform editor with zoom, pan, and multi-select
• Scrollable thumbnail strip of detected frame candidates
• Configurable frame size (256–4096 samples) and frame count (8–256 frames)
• Export to Serum (WAV + CLM chunk), Surge XT (.wt binary format), or as individual frame WAVs (each frame written to a folder)

Requirements

• Go 1.21+
• Linux: requires a C compiler and GPU/OpenGL support (standard desktop installs have this)

Build & Run

# Build
go build -o wavecleaver .

# Or run directly
go run main.go

Usage

1. Load WAV — click Load WAV and pick a mono or stereo WAV file. Stereo is downmixed to mono automatically.
2. Analysis — pitch estimation and cycle detection run in the background. A status message shows progress.
3. Waveform editor
   • Scroll to zoom in/out
   • Middle-click drag (or drag on an empty area) to pan
   • Click a cycle marker to select/deselect it
   • Shift-click to select a range of cycles
4. Frame candidates panel — the thumbnail strip below the waveform shows the auto-selected representative cycles. Click thumbnails to toggle selection.
5. Frame Size / Frames — click the Size and Frames toolbar buttons to cycle through options. Each click advances to the next value.
6. Export Wavetable — click Export Wavetable, choose a filename. Use .wav for Serum or .wt for Surge XT.

Export Formats

Extension	Synthesizer	Format details
.wav	Serum (and compatible)	32-bit IEEE float WAV with a clm RIFF chunk encoding the frame size
.wt	Surge XT	vawt binary format: header + 32-bit float samples
Folder of .wav frames	Multiple	Writes each frame candidate as a numbered 32-bit IEEE float WAV in a folder

Architecture

WAV file → audio.LoadWAV() → model.Sample (float64, normalized)
    → dsp.EstimatePitchEnvelope()   [2-pass F0, async]
    → dsp.DetectCycles()             [zero-crossing guided by F0]
    → dsp.GenerateFrameCandidates()  [RMSE-based representative subset]
    → UI renders waveform + cycle overlays
    → user selects cycles
    → audio.ExportWavetable()        [resampled frames + format-specific output]

Packages:

Package	Responsibility
app/	Central controller; owns all state, drives async analysis, handles UI events
dsp/	Signal processing: pitch estimation, zero-crossing detection, autocorrelation, frame selection
audio/	File I/O: WAV loading (mono downmix + normalize), wavetable export
model/	Plain data structs: Sample, Cycles, Selection, FrameCandidates
ui/	Gio widgets: waveform viewport, draw, input, candidate panel, toolbar
util/	Stateless math helpers: resample, lerp, clamp, next power-of-2

Development

# Run all tests
go test ./...

# Test a specific package
go test ./dsp/...

Dependencies

Library	Purpose
gioui.org	Immediate-mode GUI framework
go-audio/wav	WAV file decoding
gonum/dsp/fourier	FFT for autocorrelation-based pitch detection
sqweek/dialog	Native OS file picker dialogs

License

WaveCleaver is free software released under the GNU General Public License v3.0 or later.