🦀 gifmeta

gifmeta is a small, focused tool for inspecting and modifying GIF metadata.
It’s designed for developers, artists, and anyone needing loop control and timing tweaks — fast and reliably.

❤️ Built with Rust. Sacredly simple. Zero bloat.

🧍‍♂️ Why I Built This

Because changing loop count or frame delays in GIFs was a pain.

Most tools were too heavy, too raw, or lacked reliable preview/testing.
gifmeta was born to fix that — with precise CLI commands, minimalism, and full test coverage.

🔧 Features

• 🔁 Set infinite or fixed loop count (--loop-count)
• ⏱️ Apply fixed delay to all frames (--delay)
• 🎯 Set specific frame delays (--delays 1=30,4=60)
• 📤 Output JSON metadata (--json)
• 🖼️ Extract any frame as PNG (to file or base64)
• 🧪 CLI + doc tests for core functions
• 🖼️ Side-by-side visual preview reports via run-visual-preview.sh

🙋‍♂️ Why Not Use gifsicle or gif-rs?

You can — and should, if you need full encoding pipelines.

But gifmeta wraps just the things most of us need quickly:

• 🔁 Loop control (infinite or fixed)
• ⏱ Frame delay override (global + selective)
• ✅ Verified, minimal changes
• 🔍 Human-friendly reports
• ⚙️ Ideal for future GUI integration or scripting

⚠️ What It’s Not

• ❌ Not a full GIF encoder
• ❌ Not for image content editing
• ❌ Not a general-purpose wrapper

gifmeta lives in a small, useful space — metadata tuning and clarity. Nothing more.

🧠 Why This Exists

GIFs are still everywhere — especially in messaging, memes, and UI loaders. But modifying timing or loop behavior often requires heavy tools.

gifmeta lets you do it instantly, with:

• 🦀 Native Rust speed
• 🧼 Zero bloat
• 🖥️ CLI-first ergonomics

📦 Installation

Install via crates.io!:

cargo install gifmeta

Or use directly with:

cargo run -- <command>

Install via GitHub

git clone https://github.com/madspaaskesen/gifmeta.git
cd gifmeta
cargo build --release
./target/release/gifmeta --help

Absolutely. Here’s a clean and helpful section you can add to your README.md under the Installation section:

🧰 Installation

Download the binary for your platform from the latest release.

✅ macOS Users

If you see a warning when trying to run gifmeta, macOS may have quarantined the file because it's unsigned.

To allow execution:

xattr -d com.apple.quarantine gifmeta
chmod +x gifmeta

Then run it with:

./gifmeta info yourfile.gif

You only need to do this once per download. After this, gifmeta will run normally.

Let me know if you want the same clarity for Windows (e.g., SmartScreen warnings) or Linux permissions 💛

🛠️ Usage

Info options

• --json: Get output in json format

Modify (mod) options

You can combine any of the following:

• --loop-count <n>: Set loop behavior (0 = infinite, 1 = once, 2 = twice…)
• --delay <n>: Set same delay for all frames. Unit is centiseconds (1 = 10ms).
• --delays <csv>: Override specific frames. Format: 1=15,3=50 (in centiseconds).

Show metadata

gifmeta info --input tests/testdata/loop/10frame-rainbow.gif

Show metadata output as json

gifmeta info --input tests/testdata/loop/10frame-rainbow.gif --json

Modify loop count

gifmeta mod --input tests/testdata/loop/loop-once.gif --loop-count 10 --output tests/testdata/loop/loop-once-modified.gif

Modify delay on all frames to 100ms or 10 centiseconds

gifmeta mod --input tests/testdata/timing/zero-delay.gif --delay 10 --output tests/testdata/timing/zero-delay-modified.gif

Modify frame delays using centiseconds (1 = 10ms): frame 0 → 1, frame 1 → 20

gifmeta mod --input tests/testdata/timing/zero-delay.gif --delays "0=1,1=20" --output tests/testdata/timing/zero-delay-modified2.gif

Modify delay on all frames to 150ms, set specific frame 0 to 20ms and frame 1 to 200ms.

gifmeta mod --input tests/testdata/timing/zero-delay.gif --delay 15 --delays "0=2,1=20" --output tests/testdata/timing/zero-delay-modified3.gif

Modify all values at once example

gifmeta mod --input tests/testdata/timing/zero-delay.gif --loop-count 0 --delay 15 --delays "0=2,1=20" --output tests/testdata/timing/zero-delay-modified4.gif

🖼️ Preview a GIF Frame as PNG

You can now extract a specific frame from any GIF and output it as a PNG image — either as a file or directly as base64 for web previews:

🔹 Output frame 0 as PNG to a file

gifmeta preview --input path/to/input.gif --frame 0 --output frame0.png

🔹 Output frame 3 as base64 (for GUI, web, etc.)

gifmeta preview --input path/to/input.gif --frame 3 --as-base64

If --frame is omitted, it defaults to the first frame (0). You must specify either --as-base64 or --output.

🛠️ Commands

📊 Visual Preview Report

You can run:

./run-visual-preview.sh

It will:

• Apply a set of metadata modifications
• Generate side-by-side comparisons
• Output a beautiful tests/visual/report.html

This is useful for testing transparency, timing, or human-visible playback changes.

🛤️ Roadmap

• Set loop count (v0.2.0)
• CLI structure with clap v4
• Set per-frame delays (v0.3.0)
• Frame editing with duration visuals (experimental)
• GUI Companion (Tauri, optional)

⚠️ Batch processing and WASM are intentionally skipped.
These are best handled externally with scripting or shell tooling.

👩‍💻 Contributing

Wanna help? Fork, clone, and PRs welcome. You can also suggest Codex tasks or open issues 💛

🔗 Links

• Crates.io
• Documentation (coming soon)
• GitHub

🛠 Built With

• gif
• Rust 2021
• Love, frustration, and sacred formatting

🕊️ License

MIT — do good things with it.

🌟 Author

Built by Mads Paaskesen with Rust and a soft spot for retro formats.