Users working with large CD image files may need a program to compress them for easier use and transfer. Despite having few options, ECM for Mac performs this function well, and would be a welcome option for these users.
As with other apps available through Apple's official store, the download and installation of ECM for Mac completed easily without any user input required. Upon startup, the program's basic interface did not require any user instructions, which was a good thing since none appeared to be available. Technical support for updates did appear to be present. To load files into the application, the user can either click and drag them into the window, or select them by file from a large button on the main screen. This icon was easy to identify, although a text label would have been helpful. Once loaded, the output file can be changed and its location set prior to executing the program. During testing, the files loaded easily and the conversion took place as quickly as expected. The application supports a number of common CD file formats, which is a definite plus. The program has no other options, but performs its described function well.
While limited in its usability, ECM for Mac is a good, elementary program for compressing CD file formats.
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.