SonicStage is an audio library manager created by Sony to integrate with their MiniDisc devices. The installation is bloated, takes forever and installs all kinds of drivers and barely-related crap on your Windows. Versions earlier than 3.3 mandate DRM on all tracks ripped from CD or converted with SonicStage. The user interface is quite unintuitive (that being said, 4.3 seemed friendlier than 2.0 in the short time I used them).

But I did not create this page to complain about SonicStage. I am here to talk about ATRAC, which is Sony's audio compression format, and SonicStage just happens to be an encoder.

ATRAC - Adaptive Transform Acoustic Coding - started being developed by Sony in the early nineties as an audio data reduction technique to be employed in their movie theater audio system - SDDS (Sony Dynamic Digital Sound) - that encoded 7.1 audio streams in 1168kbps and stored the data optically next to the film stock sprockets. In this capacity it competed with the Dolby AC-3 and DTS formats.

Around the same time Sony was working on a magneto-optical audio storage and playback system called MiniDisc that was launched in 1992 and used ATRAC to compress audio, reducing CD quality streams from 1411kbps (uncompressed) to 292kbps - or 146kbps in mono mode. There are several backwards- and forwards-compatible versions of the ATRAC encoder created by Sony, from v1 to v4.5 (and then, Type R and Type S), and it is said it only started sounding good in version 3. Other MiniDisc manufacturers like Panasonic and Sharp also released their own tuned versions of the encoder.

In 1999 Sony launched the first major upgrade to the ATRAC format with the release of ATRAC3. It was introduced as a response to the perceived technological superiority of the MP3 format (similar quality at much smaller bitrates), so ATRAC3 claims to achieve transparency in LP2 mode at 132kbps. There is also an LP4 mode that stores tracks in 66kbps but with noticeable quality degradation. While being based on ATRAC, it is not backwards compatible as it includes several coding improvements and modified algorithms - therefore it will not work with original MiniDisc players, only with newer MDLP (MiniDisc Long Play) devices.

The next upgrade of the format is called ATRAC3plus and was launched in 2003, still based on the same underlying technologies but with further backwards-incompatible improvements and the addition of multichannel support. It offers bitrates ranging from 48 to 352kbps and is only compatible with Hi-MD MiniDisc devices (but also compatible with several other Sony devices such as VAIO cell phones, PS3 and PSP gaming consoles, and Xplod car players).

A parallel iteration of the format is ATRAC Advanced Lossless, in which an audio stream is encoded in ATRAC3 or ATRAC3plus and the "discarded" audio data is losslessly compressed and merged to the lossy stream. That way, players that understand the extra data can play lossless audio and older players that do not can play the normal lossy stream. It is the same idea implemented by WavPack hybrid mode, mp3HD, and OptimFrog DualStream. Compression performance is quite bad, yielding ratios similar to Dakx.

The latest iteration of the format was released in 2011 and is called ATRAC9. It is focused on video game audio for Sony consoles, offering low delay, low CPU usage, broad variety of sampling rates (everything besides 44.1 and 48kHz), loop support, and a new technology called Band Extension which seems to be a variation of SBR.

Besides being implemented in several hardware devices and software programs created by Sony, the format has been licensed to other MiniDisc manufacturers such as Kenwood, Panasonic, Pioneer, Sanyo, Sharp, etc.; to Real Networks as the audio compression engine in Real Audio 8; and to Liquid Audio as a format option in their platform.

In addition to SonicStage, here you'll find a collection of command line ATRAC3plus and ATRAC9 encoders and decoders extracted from various Sony video game SDKs. They all produce weird RIFF-wrapped ATRAC streams, but with different capabilities.

You can also try the Sony ATRAC3 ACM codec, available below. It integrates with the Windows Audio Compression Manager and encodes to ATRAC3 files wrapped in the WAV container, allowing bitrates of 66, 105 and 132kbps. Keep in mind this is quite old code and probably does not reflect the best quality ATRAC3 can offer.

And if you're still using Winamp, feel free to grab the in_atrac3 plugin below, developed by Daijoubu. The interface seems to be in Japanese and it is quite confusing. It will only work with OpenMG (*.oma) unprotected ATRAC3 or ATRAC3plus files - like the ones encoded by SonicStage. It can also work with *.aa3 files (as encoded by, E.G, Sound Forge + its plugin below), but you will first have to rename the extension to .oma. I could not get it to work with tracks encoded by the PS3 or PSP encoding tools.

None of the ATRAC versions and iterations has ever been standardized or publicly documented, which in part explains the small popularity the format enjoys outside the Sony world. There is no VBR encoding at all and while there are multichannel capabilities in ATRAC3plus and ATRAC9, it is quite hard to find encoders and decoders that support them. But the FFMPEG project reverse engineered, and provides decoders for, all iterations of ATRAC in their libavcodec library.

Since the early 2010s Sony appears to be de-emphasizing the use of ATRAC, at least for end-users. Versions of SonicStage - now renamed as "Music Center" - released since that time do not offer the format as an option for ripping CDs, the only choices are MP3, AAC, WAV, and FLAC. And the latest version of Music Center goes as far as introducing functionality that can automatically convert all ATRAC songs it finds in the user's library to AAC or FLAC.

The official ATRAC home page at Sony's web site is still available here (it has not been updated since 2008 has finally been removed! But you can still visit it at the Internet Archive and you can see a mirror of the SDDS website at the same place.

ATRAC lossless compression performance in my limited test: 62,27% (using ATRAC3 132kbps base)


Date: 2007-02-05
Version: 4.3
Interface: Graphical
Platform: Win32
Download: SS43E.exe - 36.969kB

Date: 2004-03-09
Version: 2.0
Interface: Graphical
Platform: Win32
Download: SS20E.exe - 37.485kB

Date: 2010-05-13
Version: 3.1
Interface: Command line
Platform: Win32
Download: PS3_at3tool.zip - 288kB

Date: 2009-08-18
Version: 3.0
Interface: Command line
Platform: Win32
Download: PSP_at3tool.zip - 256kB

Date: 2016-01-19
Version: 3.5.0.2
Interface: Command line
Platform: Win64
Download: PS4_at9tool.zip - 76kB

Date: 2012-01-11
Version: 1.6
Interface: Command line
Platform: Win32
Download: PSV_at9tool.zip - 83kB

Date: 2001-01-12
Version: 0.98
Interface: ACM Codec
Platform: Win32
Download: Atrac3.exe - 148kB

Date: 2006-02-13
Version: 1.0.109
Interface: SoundForge 8+ plugin
Platform: Win32
Download: atracplug.zip - 679kB

Date: 2011-10-18
Version: 1.0
Interface: Winamp plugin
Platform: Win32
Download: in_atrac3.zip - 256kB
Kindly contributed by Zachary Jelesoff.