Free online AA3 to OPUS converter

What the AA3 format is

AA3 is a Sony ATRAC audio file, commonly associated with ATRAC3 or ATRAC3plus recordings managed by Sony OpenMG software. You may encounter it in libraries created with SonicStage, Sony CONNECT, or compatible MiniDisc and Hi-MD workflows. Some AA3 files contain OpenMG digital rights management, so their audio cannot be decoded by general-purpose converters.

What the OPUS format is

Opus is a lossy audio format designed for efficient music, speech, streaming, and interactive communication. It provides good quality at lower bitrates than many older codecs and is supported by modern browsers, media players, messaging applications, and VoIP software. Use it when the destination application requires .opus or when smaller files matter more than preserving the original compressed stream.

How to actually convert AA3 to OPUS

Using 101convert.com

1. Open the AA3-to-OPUS converter on 101convert.com.
2. Select the .aa3 file and choose OPUS as the output format.
3. Start the conversion and download the resulting .opus file when processing finishes.

This method requires no installed software. It works only when the AA3 file is readable and is not protected by OpenMG DRM.

Using FFmpeg on a readable AA3 file

Install an FFmpeg build with ATRAC decoding and the native or libopus encoder, then run:

ffmpeg -i "input.aa3" -c:a libopus -b:a 128k "output.opus"

Use about 64k for speech, 96k to 128k for ordinary music, or 160k to 192k when retaining more musical detail is preferable. If your build lacks libopus, replace it with the available Opus encoder or install a complete FFmpeg build.

When FFmpeg cannot read the file

If FFmpeg reports an unknown format, decoding failure, or encryption, open the recording in the Sony software that created it, such as SonicStage, and export or decode it to an uncompressed .wav file using its available file or format-conversion command. Then encode the WAV:

ffmpeg -i "decoded.wav" -c:a libopus -b:a 128k "output.opus"

Do not rename .aa3 to .opus; changing the extension does not change the codec or container.

Quality and compatibility limitations

Conversion from AA3 to Opus is a lossy-to-lossy re-encode, so it cannot restore detail discarded by ATRAC. Decode the original AA3 only once, choose the Opus bitrate according to the intended use, and keep the AA3 or WAV as the archival copy.

OpenMG-protected files may require the original Sony authorization and software; a converter cannot remove that protection. Tags, album art, replay-gain data, and Sony-specific metadata may be lost, so check the output in an Opus-capable player and retag it if necessary.