CDI
application/octet-stream
Magic Bytes
Offset: 0
43 44 30 30 31
The Compact Disc Image (CDI) is a proprietary disc image format developed by Padus, Inc. for the DiscJuggler software suite. It is primarily utilized to store digital replicas of optical media, including multi-session tracks and subchannel data necessary for preserving copy-protected discs. Although DiscJuggler is discontinued and the format is considered a legacy standard, it remains in use within retro gaming communities for distributing Sega Dreamcast homebrew software and archival backups.
Validation Code
How to validate .cdi files in Python
Python
def is_cdi(file_path: str) -> bool:
"""Check if file is a valid CDI by magic bytes."""
signature = bytes([0x43, 0x44, 0x30, 0x30, 0x31])
with open(file_path, "rb") as f:
return f.read(5) == signatureHow to validate .cdi files in Node.js
Node.js
function isCDI(buffer: Buffer): boolean {
const signature = Buffer.from([0x43, 0x44, 0x30, 0x30, 0x31]);
return buffer.subarray(0, 5).equals(signature);
}
Go
func IsCDI(data []byte) bool {
signature := []byte{0x43, 0x44, 0x30, 0x30, 0x31}
if len(data) < 5 {
return false
}
return bytes.Equal(data[:5], signature)
}API Endpoint
GET
/api/v1/cdi
curl https://filesignature.org/api/v1/cdi