AES55-2012, AES standard for digital audio engineering - Carriage of MPEG Surround in an AES3 bitstream, has been published.
MPEG-D is an ISO/IEC standard describing MPEG Surround that extends mono or stereo audio towards multiple channels. The mono or stereo audio channels represent a downmix of the original multi-channel audio that is generated by the MPEG Surround encoder. In addition the MPEG Surround encoder generates spatial side information (MPEG Surround data). An MPEG Surround decoder is able to combine this information with the downmix to result in a multi-channel audio signal. In this way backward compatibility to mono and stereo systems is achieved.
More recently, MPEG-D has been revised to include MPEG SAOC (Spatial Audio Object Coding) that uses the same method to convey the related side information over PCM.
This standard specifies how MPEG Surround or MPEG SAOC shall be carried within an AES3 bitstream where the downmix channels remain in the linear PCM domain and the MPEG Surround or MPEG SAOC data is embedded into the least-significant bits of the PCM audio data.
Posted: Thursday, January 24, 2013