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Sony SonicStage (ATRAC)

Sony Sonic Stage SonicStage is an audio library manager created by Sony to work with their MiniDisc devices. The installation is bloated, takes forever and installs all kinds of drivers and barely-related crap on your Windows. The user interface is also quite unfriendly (that being said, 4.3 seems friendlier than 2.0 in the limited tests I did).

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 the 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 AC3 and DTS formats.

Around the same time, Sony was working on a magneto-optical media storage system called MiniDisc that 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 it is said it only started sounding good in version 3. Other MiniDisc manufacturers such as 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 launched 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 old MiniDisc players, only with newer MDLP (MiniDisc Long Play) devices.

The next iteration of the format was called ATRAC3plus and launched in 2003, still based on the same underlying technologies but with further backwards-incompatible improvements. It offered bitrates ranging from 48 to 352kbps and was only compatible with Hi-MD MiniDisc devices (but also compatible with several other Sony devices such as VAIO cell phones, PS3 and PSP 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 mp3HD, WavPack hybrid mode and OptimFrog DualStream.

The latest iteration of the format is called ATRAC9, and is focused on video game audio for Sony consoles.

Besides being implemented in several hardware devices and software programs created by Sony, the format has been licensed for other MiniDisc manufacturers such as Sharp and Panasonic (as mentioned above) and to Real Networks as the audio compression engine in Real Audio 8.

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 provide.

None of the ATRAC versions and iterations has ever been publicly documented, which in part explains the small popularity the format enjoys outside the Sony world. There is no VBR encoding at all and no multichannel implementation other than the completely proprietary SDDS. But the FFMPEG project reverse engineered and provides decoders for all iterations of ATRAC in their libavcodec library.

The official ATRAC home page at Sony's web site is available here and you can see a mirror of the SDDS website at the Internet Archive.


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

If you have the in_atrac3 Winamp Plugin, please contribute it to our collection!


© Roberto Amorim. This is a sister site of RareWares