Swift Army Knife

A tiny, native macOS app for quick file chores. Drop files or a whole folder and pick what you want:

• Video — Convert to MP4 · Compress · Extract audio · Make GIF
• Image — Convert (JPG/PNG/WebP) · Resize · Compress
• Spreadsheet — CSV ⇄ XLSX

…with a live progress bar, cancel, and an Advanced sheet for tuning. Drop many files or a folder to batch-convert; each output lands next to its source, suffixed, and never overwrites the original. The menu adapts to what you drop.

A SwiftUI shell over a Rust engine (via swift-bridge). Apple-silicon only.

Setup

1. Runtime dependencies (to use the app)

Tool	Used for	Ships with macOS?
ffmpeg / ffprobe	all video ops, WebP images	no — install
sips	HEIC decode, image convert/resize/compress	✅ built in
python3 + openpyxl	CSV ⇄ XLSX	no — install

Install everything in one line (via Homebrew):

brew install ffmpeg python && /opt/homebrew/bin/python3 -m pip install --break-system-packages openpyxl

--break-system-packages is needed because Homebrew's Python is PEP 668 "externally managed". It installs openpyxl into that Python's site-packages, which is what the app calls (/opt/homebrew/bin/python3). If you'd rather not touch the system Python, a virtualenv works too — just point the app's Python path at it.

If ffmpeg is missing the app tells you and offers this command; if python3/openpyxl are missing, only spreadsheet conversions are affected (media still work).

2. Build dependencies (to build from source)

• Xcode (from the App Store) — for the Swift compiler + macOS SDK.
• Rust — curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

(swift-bridge and the crates are fetched automatically by Cargo.)

Build & run

./build.sh
open build/SwiftArmyKnife.app

build.sh compiles the Rust core (release), generates the swift-bridge glue, compiles the SwiftUI app, and assembles the .app bundle.

How it works

Finder drag ─▶ SwiftUI window ──swift-bridge──▶ Rust core ──spawn──▶ ffmpeg / sips / python3
                    ▲                                │
                    └────── progress (poll) ─────────┘

• Swift (app/) — window, drag-and-drop (files + folders), presets, Advanced sheet, progress/cancel UI, batch orchestration.
• Rust (core/) — probes each file, builds the command sequence for the chosen op, spawns and supervises the right tool (ffmpeg / sips / python3), parses progress, and manages the collision-free output path.

Tool choices worth knowing:

• HEIC/HEIF/AVIF are decoded with sips (ffmpeg mis-decodes tiled HEIC to a single tile). Image ops use sips generally so EXIF orientation is preserved.
• Spreadsheets go through a small python3 + openpyxl script (both directions, one script). Old binary .xls isn't supported (openpyxl can't read it).

Test

cd core && cargo test

The Rust core is fully testable headless — argv building, output naming, progress parsing, cancellation, and an end-to-end pass against real ffmpeg.

Scope

Video, image, and spreadsheet (CSV ⇄ XLSX) files, single or batched. Old binary .xls, audio-file and PDF tools, and a bundled (notarized) ffmpeg are possible future additions.