scope:

The present document specifies an extension to the E-AC-3 codec.

The extension adds an object-based three-dimensional spatial representation of coded audio information and metadata. It is backward compatible with the one- and two-dimensional channel-based spatial representation of coded audio information as defined in ETSI TS 102 366 [1].

NOTE: In this context, backward compatibility is defined as follows: The three-dimensional spatial representation specified in the present document can be decoded on a device compliant with the syntax and semantics specified in ETSI TS 102 366 [1]. In this case, such a device will output one- or two-dimensional channel-based audio as per the coding algorithm defined in ETSI TS 102 366 [1] alone. Thus, support for decoders specified in ETSI TS 102 366 [1] and associated user experiences are fully maintained with the extension defined herein.

The present document specifies the following:

1) Syntax and semantics of the object-based audio metadata, carried via the extensible metadata delivery format (EMDF), specified in ETSI TS 102 366 [1].

2) Syntax and semantics of metadata to control a tool for conversion of one- or two-dimensional channel-based audio to a higher number of audio signals, part of the three-dimensional spatial representation (JOC).

3) Additional requirements on the E-AC-3 decoder as specified in ETSI TS 102 366 [1].

4) Requirements on the object-based audio interface.

5) Requirements on the JOC tool.

6) Requirements on the QMF tool.

7) Informative guidance for conversion from 1) to the ADM as defined in Recommendation ITU-R BS.2076 [i.1].