LUDO (LUa DOwnloader)

LUDO is a lightweight, cross-platform download manager with:

• Native GUI built with libui-ng
• Console-only CLI (ludocon) with no GUI dependency
• Download engine in C using libcurl
• Extensible URL extraction via Lua plugins

The application lets you paste URLs in the GUI (or pass them as command-line arguments to ludocon), then resolves and downloads them through a Lua-driven plugin pipeline.

Features

• GUI downloader app (libui-ng) or console-only CLI (ludocon)
• Static Lua runtime (lua-5.2.4 from source)
• HTTP module exposed to Lua (http.get, http.get_async, http.head, http.post, cookies, URL tools)
• Cookie state shared between http.* requests and ludo.newDownload() — authenticated sessions carry over automatically
• AES-128-CBC encryption/decryption exposed to Lua (http.aes128_cbc_{en,de}crypt)
• HLS/m3u8 playlist parsing and segment download (plugins/m3u8.lua)
• Host module exposed to Lua (ludo.newDownload, logging, output-dir helpers)
• Plugin-based URL extraction (plugins/*.lua)
• Worker-threaded download processing and GUI progress updates
• Runtime settings loaded from config.ini

Project Layout

• src/ : C source code
• plugins/ : Lua extraction plugins
• third_party/libui-ng/ : UI library source
• third_party/curl-8.19.0/ : curl source
• third_party/lua-5.2.4/ : Lua source
• CMakeLists.txt : build configuration

Architecture (High Level)

• Main thread runs libui-ng event loop (uiMain())
• Worker threads handle URL tasks, Lua processing, and downloads
• Lua plugin contract:
  • validate(url) -> boolean
    • process(url) -> typically calls ludo.newDownload(...) (may provide an optional filename hint as the 4th argument)
• GUI updates are marshalled back to main thread through uiQueueMain()

Prerequisites

Windows (MSYS2 MinGW-64)

Install toolchain and common tools:

pacman -Syu
pacman -S --needed \
  mingw-w64-x86_64-toolchain \
  mingw-w64-x86_64-cmake \
  mingw-w64-x86_64-ninja \
  mingw-w64-x86_64-meson

Linux (WSL2 Ubuntu 22.04)

Install toolchain and common tools:

sudo apt update
sudo apt install pkg-config cmake libssl-dev libgtk-3-dev

This project builds libui-ng from source via CMake; Meson is not required.

CMake builds two executables:

Target	Description	Debug name	Release name
ludo	GUI downloader (requires libui-ng)	ludo-debug.exe	ludo.exe
ludocon	Console-only CLI (no GUI)	ludocon-debug.exe	ludocon.exe

Workflow

1. Build

Configure and compile from repository root:

# Debug build (GUI) — default
cmake -B build .
cmake --build build --parallel

# Release build (GUI)
cmake -B build -DCMAKE_BUILD_TYPE=Release .
cmake --build build --parallel

# Console-only (no GUI dependencies)
cmake -B build . -DBUILD_GUI=OFF
cmake --build build --parallel

2. Install

Copy executables and all assets (plugins, config, snippets, lualib, res, tools) to a local directory:

cmake --install build --prefix install
cmake --install build --prefix ~/ludo
cmake --install build --prefix C:/PortableApps/ludo
cmake --install build --prefix C:/Program Files/ludo

This creates the install/ directory with everything needed to run.

3. Run

# GUI
./install/ludo-debug.exe

# Console — download a URL
./install/ludocon-debug.exe https://www.dailymotion.com/video/x5kesuj

# Console — read URLs from file
./install/ludocon-debug.exe --file urls.txt

# Console — help
./install/ludocon-debug.exe --help

4. Test

Run a test script (output goes to install/ludo.log):

./install/ludo-debug.exe -s test_PLUGINNAME.lua
grep -E "PASS|FAIL|SUCCESS|ERROR" install/ludo.log | tail -30

5. Package

Create a ludo-<version>.zip distribution archive via CPack:

cmake --build build --target package

The package contains all executables, config, plugins, and assets — ready to unzip and run.

Configuration

Ludo reads config.ini at startup. Common settings include:

• maxDownloadRetry
• maxThread
• urlQueueCapacity
• downloadQueueCapacity
• maxRedirect
• outputDir
• pluginDir

VS Code Tasks

This repo includes .vscode/tasks.json with configure/build tasks.

• CMake: Configure
• CMake: Build
• Build (Configure + Build)

You can run default build with Ctrl+Shift+B.

Plugin System

Plugins live in plugins/ and are loaded at startup.

Included examples:

• plugins/example_plugin.lua
• plugins/generic_direct_download.lua

A plugin should return a table and implement:

function plugin.validate(url)
  return true or false
end

function plugin.process(url)
  -- typically use http.* and then call ludo.newDownload(...)
end

Notes on Static/Independent Windows Build

Current CMake is configured so ludo.exe does not require local libcurl.dll or libstdc++-6.dll next to the executable.

For Release builds, CMake also applies optimization and symbol stripping:

• -O3 and linker -s

dumpbin/objdump will still show normal Windows system DLL imports (for example KERNEL32.dll, USER32.dll, COMCTL32.dll, etc.).

Troubleshooting

1) App exits immediately with no window

• Ensure you are running the newest built executable.
• Rebuild cleanly and run again:

cmake --build build --target ludo --clean-first --parallel 4
cmake --install build --prefix install
./install/ludo.exe

2) cannot open output file ludo.exe: Permission denied

ludo.exe is still running and locked. Close it or kill it, then rebuild.

taskkill /IM ludo.exe /F
cmake --build build --target ludo --parallel 4

3) Meson note

This repository builds libui-ng from source using CMake; Meson is not required to build LUDO.

4) Plugins not loaded

Make sure plugins/ exists beside the executable. Run cmake --install build --prefix install to copy all assets.

License

This repository includes third-party components under their own licenses:

• curl
• libui-ng
• Lua

Check each upstream LICENSE/COPYING file in third_party/.