At9tool.exe _top_ -

The tool serves as the official SCEI (Sony Computer Entertainment Inc.) ATRAC9 Codec Tool . Its primary function is to encode standard audio formats (like .wav ) into the proprietary .at9 format used by modern Sony consoles, or decode those files back into a playable format for PC.

, which handles the older ATRAC3/ATRAC3plus formats used by the PSP and PS3. Common Use Cases PlayStation Modding: at9tool.exe