Editing Super Audio CD (section)

=== Direct Stream Transfer ===

To reduce the space and bandwidth requirements of DSD, a [[lossless data compression]] method called '''Direct Stream Transfer''' ('''DST''') is used. DST compression is compulsory for multi-channel regions and optional for stereo regions. It typically compresses by a factor of between two and three, allowing a disc to contain 80 minutes of both 2-channel and 5.1-channel sound.<ref name="direct-stream-digital"/>

Direct Stream Transfer compression was standardized as an amendment to the [[MPEG-4 Audio]] standard, [[ISO/IEC]] 14496-3:2001/Amd 6:2005 (Lossless coding of oversampled audio), in 2005.<ref name="dst-iso"/><ref name="dst-iso2"/> It contains the DSD and DST definitions as described in the Super Audio CD Specification.<ref name="dst-iso-ipsj"/> The MPEG-4 DST provides lossless coding of oversampled audio signals. Target applications of DST are archiving and storage of [[1-bit DAC|1-bit]] oversampled audio signals and SA-CD.<ref name="dst-chiariglione"/><ref name="dst-chiariglione-old"/><ref name="mpeg4audio-version4-2009"/>

A [[reference implementation]] of MPEG-4 DST was published as ISO/IEC 14496-5:2001/Amd.10:2007 in 2007.<ref name="dst-reference-implementation"/><ref name="dst-reference-implementation-iso"/>