swift-thumbgen

A lightweight Swift-based CLI tool to generate thumbnails from both videos and images on macOS.
Supports most common image formats (JPEG, PNG, RAW...) and video formats (MP4, MOV...).

Built with AVFoundation, CoreGraphics, and AppKit.
Output includes rich metadata such as dimensions, rotation, datetime, rating, and codec info.

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✨ Features

• 🖼️ Generate thumbnails for:

  • Videos: .mp4, .mov, .m4v
  • Images: .jpg, .jpeg, .png, .tif, .tiff, .psd, .cr2, .cr3, .nef, .arw, .dng, .rw2

• 🧠 Extracts metadata (if available):

  • Videos: duration, frame_rate, width, height, rotation, codec
  • Images: created_datetime, rotation, rating, label

• 📸 Output: .jpg thumbnails named with timestamps and unique suffixes (avoid overwrite)

• ⚡ Fast and simple CLI – no GUI needed

• 🧩 Supports batch processing of multiple files

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🚀 Usage

swift-thumbgen [options] [file1] [file2] ...

Example:

swift-thumbgen --thumbsize=400 video.mov image.cr2 image2.jpg

This will generate thumbnails with max dimensions 400×400 px and save them in the current directory:

video_20250730-161002_3F9A21B8.jpg
image_20250730-161003_EF123AC9.jpg

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⚙️ Options

Option	Description	Default
--thumbsize=XXX	Max width/height of thumbnail in pixels	200

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🛠 Build & Run

✅ Build (Debug – for development)

swift build

✅ Build (Release – optimized)

swift build -c release

The binary will be created at:

.build/release/swift-thumbgen

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▶️ Run the tool

From Swift:

swift run swift-thumbgen file1 file2 ...

From compiled binary:

.build/release/swift-thumbgen file1 file2 ...

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📦 (Optional) Install globally:

install .build/release/swift-thumbgen /usr/local/bin/swift-thumbgen

Then use anywhere:

swift-thumbgen myvideo.mov myphoto.arw

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📂 Output Files

• Output thumbnails are saved in the current working directory

• Output file format:

  [original-filename]_[timestamp]_[random].jpg
  

  Example:

  image_20250730-153413_F3A9C4D1.jpg
  

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🧪 Known Limitations

• Only supports macOS
• RAW image thumbnail support depends on system codec support (e.g., .cr2, .nef, .arw)
• Metadata extraction varies by file format

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🏗️ Build with Script

You can use the provided shell script to build native binaries for:

• Apple Silicon (arm64)
• Intel (x86_64)
• Universal (runs on both)

▶️ Usage

chmod +x ./build.sh
./build.sh

This will output:

• .build/release/swift-thumbgen-arm64
• .build/release/swift-thumbgen-x86_64
• .build/release/swift-thumbgen (universal)

You can then install globally with:

install .build/release/swift-thumbgen /usr/local/bin/swift-thumbgen

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📋 License

MIT © 2025 Meii