chdman

Display CHD file information

$ chdman info -i [path/to/image.chd]

$ chdman verify -i [path/to/image.chd]

$ chdman createcd -i [path/to/image.cue] -o [path/to/output.chd]

$ chdman createhd -i [path/to/image.img] -o [path/to/output.chd]

$ chdman extractcd -i [path/to/image.chd] -o [path/to/output.cue]

$ chdman extracthd -i [path/to/image.chd] -o [path/to/output.img]

$ chdman copy -i [path/to/input.chd] -o [path/to/output.chd] -c [lzma,zlib,huff,flac]

chdman command [-i input] [-o output] [-c compression] [options...]

chdman is the MAME Compressed Hunks of Data (CHD) manager. CHD is a lossless compression format designed for disk images used by MAME and other emulators, supporting hard disks, CD-ROMs, LaserDiscs, and GD-ROMs.
The format provides efficient compression while maintaining perfect data integrity, making it ideal for archiving game media. CHD supports delta compression against parent images to reduce storage for similar versions.

info

Display CHD header information

Validate MD5/SHA1 checksums

Create CHD from CD image (cue/bin, toc/bin, gdi)

Create CHD from raw hard disk image

Create CHD from raw data file

Create CHD from LaserDisc image

Extract CD image from CHD

Extract hard disk image from CHD

Copy CHD with optional recompression

Input file

Output file

Compression: none, or up to four comma-separated algorithms (default: lzma,zlib,huff,flac)

Create delta CHD storing only differences from parent

Hunk size must be between 16 bytes and 1 MiB. CHD format is supported by emulators for 3DO, Dreamcast, PlayStation, Saturn, Mega CD, Neo-Geo CD, PC Engine CD, and other platforms.

CHD was developed as part of the MAME (Multiple Arcade Machine Emulator) project to provide efficient, lossless compression for disk images while preserving exact data for accurate emulation.

mame(6)