/ecm

ECM (Error Code Modeler) encode/decode utilities

Primary LanguageCGNU General Public License v2.0GPL-2.0


ECM (Error Code Modeler) encode/decode utilities Version 1.0 Copyright 2002 Neill Corlett Distributed under the terms of the GNU GPL; read source code for details

Introduction

The ECM format allows you to reduce the size of a typical CD image file (BIN, CDI, NRG, CCD, or any other format that uses raw sectors; results may vary).

It works by eliminating the Error Correction/Detection Codes (ECC/EDC) from each sector whenever possible. The encoder automatically adjusts to different sector types and automatically skips any headers it encounters.

The results will vary depending on how much redundant ECC/EDC data is present. Note that for "cooked" ISO files, there will be no reduction.

Setup / Usage

Compile ecm.c and unecm.c if necessary, or use the included Win32 EXE files.

Run ECM with no parameters to see a simple usage reference:

usage: ecm cdimagefile [ecmfile]

Where "cdimagefile" is the name of the CD image file, and "ecmfile" (optional) is the name of the ECM file. If you don't specify ecmfile, it defaults to cdimagefile plus a .ecm suffix.

UNECM works the same way, but in reverse:

usage: unecm [--cue] ecmfile [outputfile]

"ecmfile" must end in .ecm. If outputfile is not specified, it defaults to ecmfile minus the .ecm suffix.

including --cue allows to create a .cue file

Thanks to

ProtoCat for inspiring me to write this.

Where to find me

email: corlett@lfx.org