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

1      Definition

Audio Motion Flags is a Data Type representing the detected motion patterns of Audio Objects within an OSD‑described space. It provides structured classification of motion behaviour (e.g., approaching, receding), confidence scoring, optional motion vectors, and temporal windows for each Audio Object detected or processed by an AIM.

2      Functional Requirements

Motion Classification: The Data Type shall provide a primary motion classification for each Audio Object, selected from an enumerated set (Stationary, Approaching, Receding, Orbiting, Intermittent, Erratic).

Confidence Measure: Each motion classification shall include a numeric confidence in the range [0–1].

Motion Vector Support: When available, a Motion Vector (dx, dy, dz) shall provide a user‑relative 3D displacement estimate.

Object Identification: Each Audio Motion Flag shall reference the AudioObjectID it refers to.

Metadata

The Data Type shall include:

  • DataExchangeMetadata – per AIF V3.0
  • Trace – per AIF V3.0 (provenance, source AIM, timestamp)
  • DescrMetadata – descriptive metadata text (max 2048 chars)

Extensibility
The specification shall support future addition of new motion types, vector formats, predictive features, and spatial abstractions.

3      Syntax

https://schemas.mpai.community/OSD/V1.5/data/AudioMotionFlags.json

4      Semantics

Table 1 provides the semantics of the components of Spatial Cue.

Table 1 – Semantics of the Audio Motion Flags

Label Description
Header Spatial Audio Motion Flags Header – Standard “OSD-AMF-Vx,y”.
MInstanceID ID of Virtual Space the Audio Scene refers torefers to.
AudioMotionFlagsID Identifier of Spatial Cue entry.
AudioMotionFlagsData List of Audio Motion entries, one per Audio Object.
AudioObjectID Unique identifier of the Audio Object.
MotionType Classification of motion: Stationary, Approaching, Receding, Orbiting, Intermittent, Erratic.
MotionConfidence Confidence level (0–1) associated with the motion classification.
MotionVector Optional 3D vector (dx, dy, dz) expressing relative motion in user‑relative coordinates.
TemporalWindow Temporal interval expressing the window over which the motion classification was computed.
Trace AIF V3.0 trace information identifying provenance and timestamp.

5     Conformance Testing

A Data instance Conforms with V1.5 Spatial Cue (OSD-AMF) if:

  1. Its JSON Object validates against its JSON Schema.
  2. Any included  JSON Object validates against its JSON Schema.
  3. All Data in the JSON Object:
    1. Have the specified Data Types.
    2. Conform with the Qualifiers signaled in their JSON Schemas.

6     Performance Assessment