Loudness Measurements – Audio



The first plug-in is designed for performing Loudness Measurements. Its parameters are predefined in accordance to the EBU Technical Recommendation R 128.You can choose between two algorithms for loudness measurement, available in our system - ItU R BS 1770-3(3) or ItU R BS 1770-1(1). Read more about loudness normalizing in the corresponding section below. You can also refer to the ITU (International Telecommunication Union) website, http://www.itu.int/rec/R-REC-BS.1770/, to view more information about the algorithms.

Please, refer to the table below to view the user configurable parameters for this test preset:

Parameter name


Choose standard to measure the loudness: ItU R BS 1770-3(3) or ItU R BS 1770-1(1)

This is the standard (algorithm) used for loudness measurement. By default, the value is set to 3, which stands for ItU R BS 1770-3(3). If you want to use ItU R BS 1770-1(1), please set the value to 1.

Max True Peak, dBFS

This is the maximum true peak value. By default, the value is 0. The parameter can also be set to a negative number.

Zero Reference Level, dBFS

This is the reference loudness level. By default, its value is -23. It can take a value of 0 or negative values.

Deviation from Zero Reference Level correction

This parameter determines whether deviations from the Zero Reference Level parameter should be allowed. It takes only two values, -1 and 0. By default, the value here is set to 0, which means that deviations are not allowed. If you set the value to -1, the check will be ignored.




The metadata file that is sent to X-Pert Playout looks like this:

<ProgrammeLoudness>floating point number</ProgrammeLoudness>

<LoudnessRange>floating point number</LoudnessRange>

<TruePeak Channel="0" Value="floating point number"/>

<TruePeak Channel="1" Value="floating point number"/>


<TruePeak Channel="N" Value="floating point number"/>

X-Pert Playout will use the received floating point number values and interpret them in accordance to the EBU Technical Recommendation R 128 target levels, which are stated below.