chdman extracthd -i input.chd -o output.iso For example:
chdman extracthd -i "Silent Hill.chd" -o "Silent Hill.iso" The process will show a progress bar. It is fast because CHD decompression is less CPU-intensive than compression. convert chd to iso repack
Whether you are translating a rare Japanese PS1 gem, restoring a corrupted disc image, or simply learning the ropes of game preservation, mastering chdman and the ISO repack process puts you in full control of your digital disc collection. chdman extracthd -i input
Repacking refers to modifying, patching, translating, or optimizing game data before redistributing it. Since CHD files are read-only and difficult to edit, converting them back to editable ISO format is the first step for any serious game preservationist or modder. Even experienced repackers run into issues when converting
chdman createcd -i new_game.iso -o new_game.chd Note: Use createcd for CD-based games (PS1, Saturn, Dreamcast) and createhd for hard drive images. Even experienced repackers run into issues when converting CHD to ISO. Problem 1: "chdman" says "Invalid CHD file" Cause: The CHD was created from a non-standard source (e.g., a GDI for Dreamcast or a Redump BIN/CUE set that uses multiple tracks). Solution: Use chdman extractcd instead of extracthd . For multi-track discs, you may get a CUE/BIN pair, not a single ISO. Problem 2: The extracted ISO doesn't boot in an emulator Cause: Some CHDs include subchannel data (CD+G, EDC, ECC). A raw ISO discards this. Solution: Extract to BIN/CUE format, which preserves subchannel data:
Navigate to the folder containing both chdman and your CHD file.