A tool that strips out the error correction and detection codes (ECC/EDC) from a PS1 CD image. This data can take up roughly 13% of the file. The ECM tool removes it for transit and restores it automatically during extraction.
CD-quality audio tracks are converted to low-bitrate MP3/OGG or removed entirely. Dummy File Removal: Ps1 Highly Compressed Games
This is how games reach "highly compressed" status (under 50MB). Hackers manually strip out non-essential data from the game files. Common targets include: A tool that strips out the error correction