| Error Message | Probable Cause | Solution | | :--- | :--- | :--- | | Failed to open input file | File path contains spaces or is read-only | Use quotes: at9tool.exe -d "C:\My Files\song.at9" out.wav | | Unsupported sample rate | AT9 requires specific rates (44.1k, 48k, 96k) | Resample your WAV to 44.1 kHz or 48 kHz in Audacity first | | Bitrate out of range | AT9 has a minimum bitrate (24 kbps for mono) | Use -b 64 or higher | | Corrupted AT9 header | The file is encrypted or from a PS4 PKG | Use a decryption tool like PS4 PKG Tool before running AT9Tool |

is the official codec tool used to encode standard audio (like

To decode AT9 files legally:

ATRAC9 is incredibly efficient. It offers high audio quality at very low bitrates. For example, an ATRAC9 file at 64 kbps can sound comparable to an MP3 at 128 kbps. For handheld devices like the Vita, where storage space and battery life were premium commodities, this efficiency was vital.

This encodes music.wav at 128 kbps with a loop from sample 0 to 882,000.

Many games require seamless looping of background music. AT9 supports embedded loop metadata. When using -loop , the values are in . For example, if your WAV is 44.1 kHz stereo and you want a 2-second intro before looping a 10-second segment:

If you’ve ever tried to mod audio for a PlayStation 4 or PS Vita game, you’ve likely run into the file extension. This is Sony’s proprietary

and want to use it via the Command Prompt, here are the most common commands: 1. Encoding (WAV to AT9): at9tool.exe -e -br 144 input.wav output.at9 Use code with caution. Copied to clipboard : Specifies "Encode." : Sets the bitrate (144kbps is common for high quality). 2. Decoding (AT9 to WAV): at9tool.exe -d input.at9 output.wav Use code with caution. Copied to clipboard : Specifies "Decode." Troubleshooting Common Issues Missing DLLs: If the tool fails to launch, you likely need the Microsoft Visual C++ 2008 Redistributable (MSVCR90.dll) installed. 64-bit Only: Most modern versions of this tool will only run on 64-bit (x64) Windows FMOD Compatibility: Note that while at9tool.exe creates standalone

In a command prompt, users often use specific flags to ensure proper conversion for console hardware. For example: .\at9tool.exe -e -br 144 -wholeloop BGM.wav BGM.at9 This command encodes a WAV file into an AT9 file with a bitrate of 144kbps and enables whole-file looping.

: ATRAC9 is the successor to ATRAC3 and was designed for game-centric use, offering high compression with low CPU and memory overhead.

at9tool.exe -d input.at9 output.wav

: A GUI that supports bulk conversion for ATRAC3, ATRAC3plus, and ATRAC9. AutoAT9Tools