1     Definition 2     Functional Requirements 3     Syntax
4     Semantics 5    Conformance Testing 6     Performance Assessment

1    Definition

Data describing the characteristics of an object as pertains Audio.

2     Functional Requirements

  1. Object Audio Characteristics includes
    1. Reflectivity
      1. Early Reflections Time (s)
      2. Late Reflections Time (s)
    2. Reverberation
      1. RT60 (frequency dependent)
      2. RT30 (frequency dependent)
      3. R20 (frequency dependent)
      4. EDT (Time taken by audio from full scale to -10 dB)
    3.  Diffusion: Schroeder Diffusion Coefficient (number)
    4. Absorption: Absorption Coefficient (number 0 to 1)

3     Syntax

https://schemas.mpai.community/OSD/V1.4/data/ObjectAudioCharacteristics.json

4     Semantics

Label Size Description
Header N1 Bytes Texture Header
– Standard-Texture 9 Bytes The characters “OSD-OAC-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
M-InstanceID N4 Bytes Identifier of M-Instance.
ObjectAudioCharacteristicsID N5 Bytes Identifier of Texture.
ObjectAudioCharacteristics N6 Bytes Data of Object Audio Characteristics
– Reflectivity N7 Bytes The reflection of sound in the same medium after hitting a surface.
  – EarlyReflectionTime N8 Bytes Measured in seconds
  – LateReflectionTime N9 Bytes Measured in seconds
– Reverberation N10 Bytes The persistence of sound after it has been produced
  – RT60 N11 Bytes Table with frequency (Hz) and dB
  – RT30 N12 Bytes Table with frequency (Hz) and dB
  – RT20 N13 Bytes Table with frequency (Hz) and dB
  – EDT N14 Bytes Time taken by audio from full scale to -10 dB (ms).
– Diffusion N15 Bytes The spreading of sound waves throughout a space, measured by the Schroeder Diffusion Coefficient (number).
– Absorption N16 Bytes The loss of energy affected by sound waves that have reached an absorbent material measured by the Absorption Coefficient (1 ≥ number ≥ 0).
ObjectAudioCharacteristicsRights N16 Bytes Rights to Act on the Object Audio Characteristics.
DescrMetadata N17 Bytes Descriptive Metadata

5     Conformance Testing

A Data instance Conforms with Object Audio Characteristics (OSD-OAC) if:

  1. The Data validates against the Object Audio Characteristics’s JSON Schema.
  2. All Data in the Texture’s JSON Schema
    1. Have the specified type
    2. Validate against their JSON Schemas
    3. Conform with their Data Qualifiers, if present.

6     Performance Assessment