Definition
Functional Requirements
Syntax
Semantics
Conformance Testing
Performance Assessment
Definition
Audio CXE Directive (PGM-ACD) is a Directive issued by A‑User Control that specifies which audio properties shall be produced by Audio Context Enhancement SubAIMs by selecting, at property level, the required, optional, or non-requested attributes derived from Audio Scene Descriptors, together with temporal constraints and associated metadata for identification, exchange, and description.
Functional Requirements
- Directive Identification and Traceability: The directive shall include a unique identifier (AudioCXEDirectiveID) and a timestamp (AudioCXEDirectiveTime) to ensure traceability and correlation with execution status.
- Environment Identification: The directive shall include identifiers for the M-Instance (MInstance) and U-Environment (UEnvironment) in which the directive applies.
- Property-Based Control: The directive shall specify property-level requests indicating which audio attributes must be produced.
- Audio Object Identification Control: The directive shall enable selection of object identification properties such as ObjectIdentifiers.
- Motion and Proximity Control: The directive shall enable selection of motion and spatial relationship properties including Velocity, Distances, and ProximityClass.
- Acoustic Environment Control: The directive shall enable selection of AcousticProfile properties including frequency, timbre, spectral, and environmental attributes.
- Salience Mapping Control: The directive shall enable selection of salience outputs such as ranking and filtering of audio objects.
- Selective Property Activation: Each property shall be independently selectable with values indicating whether it is required, optional, or not requested.
- Temporal Control: The directive may include TemporalScope to control whether processing is instantaneous or windowed.
- Processing Window Specification: When temporal processing is windowed, the directive may include a WindowDurationMs specifying the duration.
- Data Exchange Metadata: The directive shall include DataXMData to provide standardised metadata supporting interoperability, traceability, and data exchange control.
- Descriptive Metadata: The directive may include DescrMetadata to provide additional human-readable context.
Syntax
https://schemas.mpai.community/PGM1/V1.0/data/AudioCXEDirective.json
Semantics
| Label | Description |
| Header | Directive header identifier matching pattern “PGM-ACD-Vx.y”. |
| MInstance | Identifier of the M-Instance in which the directive applies. |
| UEnvironment | Identifier of the U-Environment associated with the directive. |
| AudioCXEDirectiveID | Unique identifier for this Audio CXE Directive instance. |
| AudioCXEDirectiveTime | Timestamp indicating when the directive was produced. |
| PropertyRequests | Container specifying requested properties for each Audio CXE SubAIM. |
| – AudioObjectIdentification | Specifies requests for audio object identification properties. |
| – ObjectIdentifiers | Indicates whether audio object identifiers shall be produced. |
| – MotionProximity | Specifies requests for motion and proximity properties. |
| – Velocity | Indicates whether velocity of audio objects shall be computed. |
| – Distances | Indicates whether distances between audio objects shall be computed. |
| – ProximityClass | Indicates whether proximity classification shall be produced. |
| – AcousticEnvironment | Specifies requests for AcousticProfile properties. |
| – FrequencyRange | Indicates whether frequency bounds shall be produced. |
| – Timbre | Indicates whether timbre characteristics shall be produced. |
| – Spectrogram | Indicates whether spectrogram representation shall be produced. |
| – Loudness | Indicates whether loudness shall be computed. |
| – Reflectivity | Indicates whether reflectivity characteristics shall be produced. |
| – Reverberation | Indicates whether reverberation properties shall be produced. |
| – Diffusion | Indicates whether diffusion shall be computed. |
| – Absorption | Indicates whether absorption properties shall be produced. |
| – Doppler | Indicates whether Doppler-related effects shall be computed. |
| – SalienceMapping | Specifies requests for salience-based outputs. |
| – RankedObjects | Indicates whether audio objects shall be ranked by relevance. |
| – FilteredSalientObjects | Indicates whether filtered salient objects shall be produced. |
| TemporalScope | Defines temporal scope of processing. |
| – Mode | Indicates whether processing is instantaneous or windowed. |
| – WindowDurationMs | Duration of processing window in milliseconds when applicable. |
| DataXMData | Data Exchange Metadata compliant with MPAI-PTF V1.0. |
| DescrMetadata | Optional descriptive metadata providing human-readable context. |