IEC 60958-4-2:2016 specifies the format for coding metadata, or subcode, that relates to the audio content and is carried with it. This part of IEC 60958, together with IEC 60958-1, IEC 60958-4-1, and IEC 60958-4-4, specifies an interface for serial digital transmission of two channels of periodically sampled and linearly represented digital audio data from one transmitter to one receiver. This first edition, together with IEC 60958-4-1 and IEC 60958-4-4, cancels and replaces IEC 60958-4 published in 2003 and its Amendment 1:2008 and constitutes a technical revision. This edition includes the following significant technical changes with respect to IEC 60958-4:2003 with its Amendment 1:2008:
- support for a wider range of physical media,
- support for a wider range of audio sampling frequencies,
- deprecation of "minimum implementation" of channel status data.