At9tool.exe -

Most versions require a 64-bit operating system. Common Usage Commands

AT9 (sometimes referred to as ATRAC9) is a lossy audio compression codec developed by Sony. It is the successor to the older ATRAC (Adaptive Transform Acoustic Coding) family used in MiniDiscs and earlier PlayStation portables. at9tool.exe

It is a Windows-native application. While it can run on Linux using Wine , it requires specific configurations. Most versions require a 64-bit operating system