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:
- Run the CD image file (i.e. filename.bin) through ECM to create an ECM file (i.e. filename.bin.ecm).
- Compress the ECM file (i.e. filename.bin.ecm) using your favorite compression program.
- Back up, transmit via Internet, or whatever you normally do with CD images!
- 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%
Cool, I wanna try!
Download ECM v1.0
ECM works on a variety of platforms and is
GPL licensed. Source code and a 32-bit Windows binary are included.
Zack Schilling has done a
GUI port for Mac OS X.
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.