ecm

ECM(1)                                                                  ECM(1)



NAME
       ecm - selectively strips error correction codes from CD images

SYNOPSIS
       ecm  cdimagefile [ecmfile]

DESCRIPTION
       ecm reduces the size of a CD image file (ISO, BIN, CDI, NRG, CCD or any
       other format that uses raw sectors) by eliminating the Error Correction
       Codes  (EEC) and Error Detection Codes (EDC) from each sector when pos‐
       sible.

       Since the data ecm strips is usually nearly impossible to compress with
       traditionnal  tools,  the  resulting  ECM file will compress far better
       than the raw CD image.

       Hard drives already have mecanisms to protect data  integrity,  EEC/EDC
       data can thus be discarded safely.

       This data can then be generated again using the command unecm.

       Because  ecm  only discards EDC/ECC data for sectors where it's verifi‐
       ably possible to recreate that data, the process is lossless.  In  case
       of copy protection, ecm will preserve the bogus data.

EXAMPLES
       ecm foo.bin
              strips  the  ECC/EDC data from the foo.bin CD image and save the
              resulting file as foo.bin.ecm

       ecm foo.img foobar
              strips the ECC/EDC data from the foo.img CD image and  save  the
              resulting file as foobar

SEE ALSO
       unecm(1).

AUTHOR
       ecm was written by Neill Corlett.

       This  manual  page was written by Loïc Martin ,
       for the Debian project (but may be used by others), using the  documen‐
       tation written by ECM author Neill Corlett.



                               December 22, 2008                        ECM(1)