notipdf 🎺📄

A minimalist PDF preprocessing tool for optimizing sheet music being used for e-ink devices.

✨ Motivation

notipdf is a small, focused tool to prepare sheet music PDFs for real-world use — especially on E-Ink devices like the PocketBook InkPad.

The core idea is simple:

Simplicity is key.

No heavy frameworks. No bloated UI. No cloud.

Just:

• open a PDF
• select what you need
• export clean, optimized pages

🚀 Features

• 📄 Load and view PDFs (fast, lightweight)
• 🔍 Smooth pan & zoom (GLFW-based)
• 🖱️ Rectangle selection (single selection, moveable)
• 🔄 Page navigation (j/k or n/p)
• 🔁 Rotation support (90° steps)
• 📤 Export cropped regions as optimized PDFs
• 🧾 Automatic meta.json generation (structured for library use)
• 🎯 Optimized output for E-Ink devices (e.g. 1404×1872 @ 300 DPI)

🧱 Dependencies

You need:

• C++17 compatible compiler
• CMake (≥ 3.28)
• MuPDF (installed via system)
• (optional) ImageMagick for PDF writing

macOS

Use Homebrew to install the required package(s).

brew install mupdf

Linux

sudo apt libgumbo-dev libmujs-dev libharfbuzz-dev libopenjp2-7-dev libjpeg-dev libjbig2dec0-dev install libgl1-mesa-dev libglu1-mesa-dev libfreetype-dev libx11-dev libxrandr-dev libxinerama-dev libxi-dev libxcursor-dev libmupdf-dev imagemagick

🛠️ Build Instructions

First, clone the repository to your local machine.

git clone https://github.com/breiting/notipdf

then build it:

cd notipdf

cmake -B build
cmake --build build

finally start the GUI application with a sample PDF file:

./build/notipdf input.pdf

🎮 Controls

• j / n → next page
• k / p → previous page
• r → rotate (counter-clockwise)
• f → fit to screen
• q → quit

Workflow

Use the Spacebar to toggle between navigation and selection. Before starting the selection you can lock the aspect ratio using the l key (currently optimized for InkPad 4).

Make sure to switch to the selection mode and then use the mouse to drag a rectangle, selecting the area for export. If a selection is present, the mouse is used to move the selection box.

If you want to delete the selection use the Delete or Backspace key.

Export

• e → open export dialog

Dialog fields:

• Book
• Piece number
• Title
• Author
• Instrument

Result:

library/
  marschbuch/
    006_47er/
      meta.json
      trompete_2.pdf

⚙️ Configuration

Config file location:

$XDG_CONFIG_HOME/notipdf/config.json

Example:

{
  "output_directory": "/Users/you/notipdf/library",
  "default_book": 0,
  "default_instrument": 0,
  "optimize_for_eink": true,
  "threshold_black_white": false,
  "pdf_backend": "sips"
}

PDF backends

• "sips" (macOS default)
• "magick" (cross-platform via ImageMagick)

📚 Data Model

• Book → Piece → Instrument
• meta.json is written per piece
• Multiple instruments per piece supported

Example:

{
  "book": { "id": "marschbuch", "title": "Marschbuch" },
  "piece": { "number": 6, "id": "47er", "title": "47er" },
  "instruments": [
    { "id": "trompete_2", "title": "2. Trompete", "pdf": "trompete_2.pdf" }
  ]
}

📦 Libraries Used

• GLFW → window + input
• OpenGL → rendering
• MuPDF → PDF rendering
• Dear ImGui → minimal dialogs
• nlohmann/json → JSON handling

📄 License

MIT License

🎯 Philosophy

notipdf is intentionally small.

If something feels complicated, it’s probably wrong.

🙌 Final Note

Feel free to fork the repository and change it to your needs.