Test ID
All Reference Audio files begin with a unique “Test ID” and Frontline’s Audio Expert System is continuously scanning the received audio in search of a valid Test ID. On recognition of a valid Test ID, the “Referenced Mode” state is declared. This state then enables the system to perform more thorough testing of the audio data than can be performed in the non-referenced mode. The system uses the Test ID to determine which test script to use to evaluate the received audio.
A “Test ID” is three digits minimum in length, representing a dot notation “N.vv” Test Identifier. The value ‘N’ may be any length >= 1, indicating a specific test, and “vv” represents a two digit version. Each digit is represented by a tone between 200 and 290 Hz, and is followed by either a 1 kHz delimiter tone or a 400 Hz Test ID terminator. The digit ‘0’ is represented by 200 Hz, the digit ‘1’ by 210 Hz, and so on, up to the digit ‘9’ represented by 290 Hz.
The frequency 400 Hz received following the last digit terminates the digit string. There is no encoding of the ‘.’ (dot character) but test script naming conventions include the string in “N.vv” format, as in “Test_1.01_44.1kHz_16Bit.xml”.