OpenMG

OpenMG is a SDMI-compliant digital rights management system by Sony. It is designed for audio files in ATRAC3 format. The compliant software, e.g. Sony SonicStage, is usually capable of transcoding MP3 and wav files to OpenMG/ATRAC3. The file extensions OpenMG-encrypted files use are .omg and .oma.

There has already been at least one reported case when a security update of Windows broke OpenMG-compliant software. This issue was later resolved.

Sonicstage 3.4 includes an option to remove DRM from one's entire media library, allowing unrestricted use. However, this feature is disabled for copies without a license.

The compliant music organization systems, e.g. OpenMG Jukebox, work by "checking out" and "checking in" the files to/from portable players, keeping only one copy unlocked in order to hinder proliferation of copies.

The 'checking in' and 'checking out' of files is often cumbersome and risky in comparison with unprotected data. Side effects include user complaints of being locked out of their own original recordings, unable to transfer them to the computer. With the combination of OpenMG with MagicGate, Sony intends to restrict the files to be only moved instead of copied, artificially emulating the restrictions of physical objects. However, as of the most recent releases of Sonicstage, files can be "checked out" of the library an unlimited number of times to a portable device, without the need to "check in" any of them.

OpenMG modules also tend to choke on corrupted MP3 ID3 tags.

With some Sony portable audio players it is not possible to directly drag and drop the desired tracks to the device's visible directory structure; a considerably more cumbersome process using Sony's own or compatible software must be performed.

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Wikipedia