ECM is now included as part of the Command-Line Pack.

See the Command-Line Pack page for download links.

What is ECM, and why should I use it?

ECM (Error Code Modeler) lets you prepare CD image files (such as BIN, CDI, NRG, CCD, or similar) so that they'll compress far better in programs such as WinRAR. Here's how to use it:

  1. Run the CD image file (i.e. filename.bin) through ECM to create an ECM file (i.e. filename.bin.ecm).
  2. Compress the ECM file (i.e. filename.bin.ecm) using your favorite compression program.
  3. Back up, transmit via Internet, or whatever you normally do with CD images!
  4. When you want to burn the CD again, extract the original CD image from the ECM file.

How ECM Works - Here's a quick summary.

How much space does it actually save?

The space saved depends on the number of sectors with unnecessary EDC/ECC data in them, which will depend on the specific type of CD. Here are some examples:

Test CD                              Format   Size (RAR)   Size (ECM, then RAR)  Improvement
Metal Gear Solid (PSX) Disc 1        BIN/CUE  466,852,244  381,033,267           18.4%
Panzer Dragoon Saga (Saturn) Disc 1  BIN/CUE  432,909,436  366,889,519           15.3%
Tokyo Xtreme Racer 2 (Dreamcast)     CDI      474,346,319  389,917,790           17.8%

Obligatory disclaimer

ECM is not intended as a tool to aid in acts of copyright infringement. I do not support or condone such acts.

No, seriously, I don't.


contact Neill Corlett