1       Definition

An Object with Audio perceptibility attributes.

2       Functional Requirements

An Audio Object supports:

  1. The ID of a Virtual Space (M-Instance) where it is or is intended to be located.
  2. The ID of the Audio Object.
  3. The ID(s) of Parent Object(s) supporting two cases:
    1. The Parent Object has spawned two (or more) Objects.
    2. Two (or more) Parent Objects have merged into one.
  4. The Audio Object-specific Data:
    1. The ID of Audio Object Data Format.
    2. The length in Bytes of the Audio Object.
    3. The URI of the Data of the Audio Object.
  5. The Audio Object Space-Time Attributes.
  6. The Audio Object Attributes:
    1. The ID of Audio Object Attributes’ Data Formats.
    2. The length in Bytes of the Audio Object Attributes.
    3. The URI of the Data of the Audio Object Attributes.


MPAI has specified Audio Object in Technical Specification: Context-based Audio Enhancement (MPAI-CAE) – Use Cases (CAE-USC) V2.2. It is reported here for the reader’s convenience.

3       Syntax





4       Semantics

Label Size Description
Header N1 Bytes
·         Standard-AudioObject 9 Bytes The characters “CAE-AOB-V”
·         Version N2 Bytes Major version – 1 or 2 characters
·         Dot-separator 1 Byte The character “.”
·         Subversion N3 Bytes Minor version – 1 or 2 characters
MInstanceID N4 Bytes Identifier of M-Instance.
AudioObjectID N5 Bytes Identifier of the Audio Object.
ParentAudioObjects N6 Bytes Identifier(s) of Parent Audio Objects.
AudioObjectData N7 Bytes Data associated to Audio Object.
·         AudioObjectFormatID N8 Bytes Audio Object Format Identifier
·         AudioObjectLength N9 Bytes Number of Bytes in Audio Object
·         AudioObjectDataURI N10 Bytes URI of Data of Audio Object
AudioObjectSpaceTimeAttributes N11 Bytes
AudioObjectAttributes[] N14 Bytes
·         AudioObjectAttributeID N15 Bytes ID of Attribute of Audio Object
·         AudioObjectAttributeFormatID N16 Bytes ID of Attribute Format of Audio Object
·         AudioObjectAttributeLength N17 Bytes Number of Bytes in Audio Object
·         AudioObjectAttributeDataURI N18 Bytes URI of Data of Audio Object
DescrMetadata N18 Bytes Descriptive Metadata

5       Data Formats

Audio Object requires the specification of

  1. Audio Formats
  2. Audio Attributes
  3. Audio Attribute Formats.

6       To Respondents

MPAI advises Respondents that that the Audio Object Functional Requirements have been developed considering the needs of the various application domains of its Technical Specifications. The current draft specification supports them all. An application not needing some functionalities is allowed to drop them.

MPAI requests:

  1. Comments on Functional Requirements and their support by the JSON Syntax.
  2. Comments on existing Audio Formats, Attributes, and Attribute Formats and Proposal for new entries.