1     Function 2     Reference Model 3     Input/Output Data
4     SubAIMs 5     JSON Metadata 6     Profiles
7     Reference Software 8     Conformance Texting 9     Performance Assessment

1     Functions

Audio Descriptor Multiplexing (CAE-AMX):

Receives Enhanced Audio Objects Audio Objects with reduced noise.
Audio Scene Geometry The spatial arrangement of Audio Objects.
Multiplexes Enhanced Audio Objects  
Audio Scene Geometry  
Produces Audio Scene Descriptors The Descriptors of the Audio Scene.

2     Reference Model

Figure 1 depicts the Reference Architecture of the Audio Descriptor Multiplexing AIM.

Figure 1 – The Audio Descriptor Multiplexing AIM

3    Input/Output Data

Table 1 specifies the Input and Output Data of the Audio Descriptor Multiplexing AIM.

Table 1 – I/O Data of Audio Descriptor Multiplexing

Input Description
Enhanced Audio Object Time-domain Audio Objects without noise.
Audio Scene Geometry The Space-Time arrangement of Audio objects in an Audio Scene
Output Description
Audio Scene Descriptors The combination of Audio Scene Geometry and Audio Objects.

4     SubAIMs

No SubAIMs.

5     JSON Metadata

https://schemas.mpai.community/CAE1/V2.3/AIMs/AudioDescriptorsMultiplexing.json

6     Profiles

No Profiles.

7     Reference Software

8     Conformance Testing

The following steps shall be followed when testing the Conformance of a CAE-AMX AIM instance.

  1. Use the following datasets:
    1. DS1: n Enhanced Audio Objects Test files.
    2. DS3: n Audio Scene Geometry of the Enhanced Audio Objects.
    3. DS4: n Expected Output Audio Scene Descriptors.
  2. Feed the AIM under test with the Test files (DS1, DS3).
  3. Analyse the Audio Scene Descriptors with the Expected Audio Scene Descriptors (DS4).
    1. Check the Audio Scene Descriptors with Expected given Audio Scene Descriptors.
    2. Calculate the peak-to-peak Amplitude (A) of each Audio block in the Expected Audio Scene Descriptors.
    3. Calculate the RMSE of each Audio block by comparing the output (x) with the Audio Scene Descriptors (y) Audio blocks.
    4. Accept the CAE-AMX AIM under test if, for each audio block, these the two conditions are satisfied:
      1. Data format of Audio Scene Descriptors is the same as the Expected Audio Scene Descriptors and
      2. RMSE < A * 0.1%
  4. The Conformance Tester will provide the following matrix with a limited number of input records (n) with the corresponding outputs. If an input record fails, the tester would specify the reason why the test case fails.
Input data (DS1, DS3) Expected Output Data (DS4) Data Format RMSE
Enhanced Audio Objects ID1
Audio Scene Geometry ID1		 Audio Scene Descriptors ID1 T/F < A * 0.1%
Enhanced Audio Objects ID2
Audio Scene Geometry ID2		 Audio Scene Descriptors ID2 T/F < A * 0.1%
Enhanced Audio Objects ID3
Audio Scene Geometry ID3		 Audio Scene Descriptors ID3 T/F < A * 0.1%
… … …
Enhanced Audio Objects IDn
Audio Scene Geometry IDn		 Audio Scene Descriptors IDn T/F < A * 0.1%
  1. Final evaluation: T/F Denoting with i, the record number in DS1 and DS3, the matrices reflect the results obtained with input records i with the corresponding outputs i.
DS1 DS3 DS4 CAE-AMX output value
(obtained through the AIM under test)
DS1[i] DS3[i] DS4[i] Multiplexer[i]

Table 3 provides the Conformance Testing Method for the formats of the CAE-AMX AIM output.

Note: If a schema contains references to other schemas, conformance of data for the primary schema implies that any data referencing a secondary schema shall also validate against the relevant schema, if present and conform with the Qualifier, if present.

Table 2 – Conformance Testing Method for CAE-AMX AIM

Receives Enhanced Audio Objects Shall validate against Audio Object schema.
Audio Data shall conform with Audio Qualifier.
Audio Scene Geometry Shall validate against Audio Basic Scene Geometry schema.
Produces Audio Scene Descriptors Shall validate against Audio Basic Scene Descriptors schema.

9     Performance Assessment