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 Synthesis Transform (CAE-AST):

Receives Enhanced Audio Object (Transform)  with associated Microphone Array info.
Transforms Enhanced Audio Object (Transform)  from the frequency domain to the time domain via an Inverse Fast Fourier Transform (IFFT).
Produces  Enhanced Audio Object  with associated Microphone Array info.

2     Reference Model

Figure 1 depicts the Reference Architecture of the Audio Synthesis Transform (CAE-AST) AIM.

Figure 1 – The Audio Synthesis Transform (CAE-AST) AIM

3    Input/Output Data

Table 1 specifies the Input and Output Data of the Audio Synthesis Transform (CAE-AST) AIM.

Table 1 – I/O Data of Synthesis Transform (CAE-AST) AIM

Input Description
Enhanced Audio Objects Audio Objects in the time-frequency domain.
Output Description
Enhanced Audio Objects Audio Objects in the time domain.

4     SubAIMs

No SubAIMs.

5     JSON Metadata

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

6     Profiles

No Profiles.

7     Reference Software

8     Conformance Testing

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

  1. Use the following datasets
    1. DS1: n Test files including data in Enhanced Audio Objects (Transform).
    2. DS2: n Expected Output files including data in Enhanced Audio Objects.
  2. Feed the AIM under test with the Enhanced Audio Objects (Transform) Test files (DS1).
  3. Analyse the Enhanced Audio Objects  with the Expected Enhanced Audio Objects (DS2) with the following steps:
    1. Check the Enhanced Audio Objects data format with the given Expected Enhanced Audio Objects format.
    2. Calculate the peak-to-peak Amplitude (A) of each Audio block in the Expected Enhanced Audio Objects.
    3. Calculate the RMSE of each Audio block by comparing the output (x) with the Expected Enhanced Audio Objects (y) Audio blocks.
    4. Accept the AIM under test if, for each audio block, these the two conditions are satisfied:
      1. Data format of the Enhanced Audio Objects is the same with the Expected Enhanced Audio Objects 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) Expected Output Data (DS2) Data Format RMSE
Enhanced Audio Objects ID1 Enhanced Audio Objects ID1 T/F < A* 0.1%
Enhanced Audio Objects ID2 Enhanced Audio Objects ID2 T/F < A* 0.1%
Enhanced Audio Objects ID3 Enhanced Audio Objects ID3 T/F < A* 0.1%
… … …
Enhanced Audio Objects IDn Enhanced Audio Objects IDn T/F < A* 0.1%
  1. Final evaluation: T/F Denoting with i, the record number in DS1 and DS2, the matrices reflect the results obtained with input records i with the corresponding outputs i.
DS1 DS2 Synthesis Transform output value (obtained through the AIM under test)
DS1[i] DS2[i] SynthesisTransform[i]

Table 2 provides the Conformance Testing Method for the CAE-AST AIM for the formats of the CAE-AST 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-AST AIM

Receives Enhanced Audio Object (Transform)  Shall validate against Audio Object schema.
Audio Data shall conform with Audio Qualifier.
Produces  Enhanced Audio Object  Shall validate against Audio Object schema.
Audio Data shall conform with Audio Qualifier.

9     Performance Assessment