audioscope

Inspect, play, and compare audio inside VS Code.

Features

Sample inspection — zoom into individual samples and read per-channel amplitudes.

Follow playback — keep the playhead in view as the audio plays.

Loop selection — select a range, adjust its edges, and repeat it.

Spectrogram — inspect time and frequency with synchronized zoom and hover readouts.

Analysis views — switch between spectrogram, mel, MFCC, scalogram, and chroma; tune the analysis settings.

Loudness — view momentary and short-term LUFS curves, plus integrated loudness, LRA, peak, and true peak.

• Compare files: align A/B audio, match gain, and inspect the A − B residual or spectral level difference.
• Selection analysis: inspect spectrum, peak, RMS, and DC offset; copy spectrum data as CSV.
• Export: save a selection or the whole file as WAV, MP3, M4A, or FLAC.
• Playback: adjust speed, volume, and waveform amplitude; seek and zoom to a selection.
• Metadata: inspect codec, format, tags, and chapters with chapter navigation.
• Experimental: view channels separately and accelerate analysis with WebGPU (WASM fallback).

Quick Start

1. Install the extension and open an audio file.
2. If needed, right-click the file and choose Open in audioscope.
3. To compare, select two audio files in the Explorer and choose Compare Audio Files….

The editor is read-only. VS Code Media Preview may take precedence on first open.

Supported formats: WAV, MP3, OGG, FLAC, M4A, AAC, Opus, and AIFF.

Settings

Open VS Code Settings and search for audioscope to adjust analysis quality, defaults, and experimental features. Playback volume, waveform amplitude, and the panel split are saved automatically.

Development

Build prerequisites:

• bun
• zig 0.15+
• Emscripten toolchain
• FFmpeg submodule checkout

Build from source:

bun install
git submodule update --init --recursive
bun run compile

The full build compiles:

• embedded FFmpeg / ffprobe WASM tools
• analysis WASM binaries
• webview bundles
• extension host output

Third-Party And Vendor Code

This repository includes vendored and third-party source.

• src-wasm/third_party/ffmpeg The FFmpeg source tree vendored as a submodule and used to build the embedded FFmpeg / ffprobe WebAssembly binaries. Upstream repository: https://github.com/FFmpeg/FFmpeg
• src-wasm/third_party/pffft PFFFT and FFTPACK-based FFT code used by the analysis WASM runtime. Original PFFFT repository: https://bitbucket.org/jpommier/pffft/
• src-webview/vendor/SignalsmithStretch.mjs Vendored Signalsmith Stretch Web module used for time-stretch playback in the webview transport path. Official upstream: https://signalsmith-audio.co.uk/code/stretch.git GitHub mirror: https://github.com/Signalsmith-Audio/signalsmith-stretch

Licensing and attribution details for bundled third-party code are documented in THIRD_PARTY_NOTICES.md. FFmpeg rebuild notes and revision details are documented in FFMPEG_SOURCE.md.

License

MIT