Most fan-translation patches (XDelta, IPS, or PPF) are designed for ISO or BIN/CUE files. Applying a translation patch directly to a CHD is impossible without decompression.
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:
chdman extractcd -i game.chd -o game.cue
This generates a .cue file and a .bin file. Use the .cue file with your emulator. convert chd to iso repack
Even experienced repackers run into issues when converting CHD to ISO.
Want to insert a high-res texture pack into Final Fantasy VII? Need to replace audio tracks in a Sega Saturn title? You must first convert the compressed CHD back into a writable ISO. Most fan-translation patches (XDelta, IPS, or PPF) are
The standard tool for this conversion is chdman , which is part of the MAME tool suite. There is no "magic software" needed; chdman is the industry gold standard.
If the raw file has a companion .cue (Cuesheet), use: This generates a
bchunk game.raw game.cue repacked_temp.iso
The command to convert a CHD file to an ISO file using qemu-img is:
qemu-img convert -f chd -O raw <input_file>.chd -o format=raw <output_file>.iso
Or, for a more direct conversion (if supported):
qemu-img convert -f chd -O iso <input_file>.chd <output_file>.iso
Replace <input_file>.chd and <output_file>.iso as necessary.