Related to STYLE-381

The proposal is to add medium formats to represent the different data areas on SACD mediums and stems from the discussion here... https://community.metabrainz.org/t/sacd-release-missing-hi-def-stereo-tracks/487829

The SACD spec calls for 2 areas on the SACD layer, one for HD 2ch and one for HD multichannel (Mch).  You typically have to change a setting on your SACD player to be presented with one or the other.  This proposal would add new medium formats to distinguish those two areas..

SACD

  SACD (CD layer)

  SACD (SACD layer)

•   (SACD (SACD layer, HD 2ch)

•    SACD (SACD layer, HD mch)

If this goes through I'm going to be a busy editor for a while!