cditools

Fast C++ command-line tools for unpacking and building DiscJuggler (.cdi) Sega Dreamcast images. Designed for automated systems and AI agent toolchains in Linux (Debian 12 tested) and Windows (WinXP or newer, 64-bit) environments.

The purpose is to replace the Python-dependent lazyboot toolchain, img4dc, mkcdi, mkdcdisc, and custom Python scripts with a single, fast, self-contained C++ tool that skips ECC generation. Builds are near-instant — only bottleneck is the external mkisofs call. cdiextractor also doubles as a Dreambeam replacement for CRC32 scanning and game identification.

This is a debugging/iteration tool, not a mastering tool. It is useful for modders and translators of classic (2000–2002) Dreamcast games who need repetitive rebuild-and-test cycles. Less useful for postmarket games (most are data/data 45k LBA, not yet supported).

Tools

Tool	Purpose
cdiextractor	Extract files, boot sector, and CRC32 scan lists from CDI images
cdibuilder	Build CDI images from directories (audio/data mode)
dreamdiff	Compare Dreambeam database files and generate color-coded diff reports
cdi7z	Open-source 7-Zip CDI format plugin (Linux) — single-step extraction

Usage Cases

• AI agents / automated pipelines: cdiextractor unpacks any CDI without Windows-only tools (no Wine, no closed-source Iso7z plugin, no 7z). Produces a Dreambeam-format CRC32 list that can be diffed directly against the Dreambeam database — one hash comparison identifies the game, no token-heavy file-by-file analysis needed. Simpler than grepping the database blindly because you can produce the same hash format from any image and get an exact match (or a deliberate mismatch).

• Boot sector extraction: cdiextractor can pull the real IP.BIN from outside the ISO9660 filesystem, which Iso7z cannot do.

• Fast rebuilds: cdibuilder skips ECC generation (emulators and ODEs don't need it), so builds are near-instant beyond the mkisofs call. Compared to mkdcdisc (which computes ECC and has a complex dependency chain that makes it painful to compile, especially on Windows), cdibuilder is a single .cpp file — trivial to modify and rebuild. Ideal for drop-in replacement in Windows automation pipelines (e.g. upgrading Lazyboot's Python-based mkcdi step for broader compatibility and speed).

• Dreambeam replacement: if the original Dreambeam doesn't run on your system (the older version have compatibility problems and modern Dreambeam was still in beta), cdiextractor -s produces the same _dbscan.txt format. Drop that file into your database and use dreamdiff (included) to compare it against existing entries — preserving the Dreambeam ecosystem without requiring the original GUI.

• Lightweight / legacy environments: both tools compile with g++ on any system with a C++17 compiler. Windows binaries can target WinXP, making them usable in minimal VirtualBox appliances where installing Python or Wine is impractical. The only external dependency is mkisofs/genisoimage.

Quick Start (Windows)

Drop a .cdi onto extract.cmd — extracts all files + bootsector + Dreambeam scan list into data/.

Or from command line:

cdiextractor game.cdi
cdibuilder -d ./game_files -V "MYGAME" -o game.cdi

Building from source

g++ -std=c++17 -O2 -o cdiextractor cdiextractor.cpp
g++ -std=c++17 -O2 -o cdibuilder cdibuilder.cpp

Windows: use build.cmd (requires MinGW-w64).

cdibuilder also requires mkisofs or genisoimage in PATH.

cdiextractor — Extract & scan

cdiextractor <image.cdi | directory> [options]

  -l, --list        List files inside the CDI
  -x, --extract     Extract files
  -b, --bootsector  Also extract IP.BIN boot sector as bootsector.bin
  -s, --scan        Generate Dreambeam-compatible _dbscan.txt (CRC32 hashes)
  -m, --match <db>  Match scan against Dreambeam database
  -C <dir>          Output directory (default: data/)
  -a, --all         Include directories when listing

cdibuilder — Build CDI

cdibuilder -d <input_dir> [options]

  -d <dir>      Input directory with game files + IP.BIN (runs mkisofs)
  -I <iso>      Input ISO file (skips mkisofs)
  -o <cdi>      Output CDI file (default: <volume>.cdi)
  -V <name>     Volume name (default: dcgame)
  -l <lba>      Session 2 LBA: 11702 for audio/data, 45000 for data/data
  -t <type>     Image type: audio or data (default: audio)

cdi7z — 7-Zip CDI plugin (Linux)

Open-source format plugin replacing Iso7z. Single-step extraction: 7z x image.cdi extracts files directly (no intermediate ISO step).

cd cdi7z/bin
LD_LIBRARY_PATH=. ./7z l image.cdi          # list files
LD_LIBRARY_PATH=. ./7z x image.cdi -o./out  # extract to folder

Features: IP.BIN display in Comment, ISO9660 dates/attributes, audio/data and data/data support. Linux x86_64 only — Windows users can use the Iso7z plugin instead.

Note: cdi7z is independent implementation based on No$cash CDI specs, cdirip 0.6.4 (DeXT/Lawrence Williams), and the 7-Zip format SDK. No code from Iso7z or third-party closed-source CDI tool is used.

mkcdi-portable-linux — All-in-One CDI Builder

Single C++17 binary replacing the mkcdi.sh bash pipeline. Handles KOS (ELF), Katana, and WinCE (bincon) builds. Merges hack4, binhack32, bincon, elf2bin, logoinsert, doomer, and cdibuilder into one executable.

cd mkcdi-portable-linux
make          # Linux x86-64
make static   # Linux x86-64 (static, no deps)
make arm64    # Linux aarch64 (static)
make win      # Windows x64 cross-compile (static)

./mkcdi --romname "Game" --data-dir ./data --output game.cdi

Pre-built static binaries included: mkcdi (x86-64), mkcdi-arm64 (aarch64), mkcdi.exe (Windows x64). External deps: mkisofs (genisoimage), cdi4dc (LBA 11702 with ECC, optional — --fast uses built-in cdibuilder).

make45k_linux — Data/Data Selfboot Builder (LBA 45000)

Experimental data/data CDI builder for games requiring LBA 45000 layout. Uses two-session build: Session 1 from data1/, Session 2 from data/, with automatic LBA calculation and padding via fill.

cd make45k_linux
python3 mkcustom-lba.py

Requires: mkisofs (genisoimage), p7zip. Creates data1/ and data/ directories — put Session 1 content in data1/, Session 2 (game data) in data/. Output is named {romname}-{timestamp}.cdi.

Internal tools (system/): iso2raw, fill, redump2cdi, hack4, binhack32, scramble, bincon.py, cdibuilder. Hack4 source updated from mkcdi-portable-linux (corrected default patch behavior).

Limitations

• cdibuilder and mkcdi-portable-linux audio/data mode only (data/data via make45k)
• No ECC/EDC generation (emulators and ODEs don't require it)
• No CDDA audio track support