1107214

Actus Loudness Specifications
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Supported Input Methods
•IP Transport Stream, Analog, Digital (SDI),
•DVB-T/T2, ASI
•Both SD and HD inputs are fully supported

Available Bitrates
•Video: 256 Kbps – 20 Mbps (Full HD)
•Audio: 64 Kbps – 1024 Kbps

Terms
Loudness Meter – any device, or software solution, that has the capability to measure the audio levels of a program.
Program Loudness – is the average Loudness Measurement over the length of a given programme.
Loudness Range – is the average dynamic range (the number of db separating the low volume from that of the high volume) of a given programme.
Maximum True Peak Level – is the approximate level of the highest volume of audio within a given programme.
Graphical Representation – Any Loudness Meter may implement a different graphical solution. There are no standards in terms of GUI.
Time Scales – the EBU specifications require that a Loudness Meter provides measurements in 3 time scales. The shortest time scale is called ‘momentary’, abbreviated ‘M’ using a rectangular time window of duration 400ms, non-gated. The intermediate time scale is called ‘short-term’, abbreviated ‘S’ using a sliding time window of duration 3s, non-gated updated at least at 10Hz. The programme- or segment-wise time scale is called ‘integrated’, abbreviated ‘I’ updated at least at 1Hz.
Gated – When applicable, a gate, or a filter, will be used, to eliminate all measurements which are below a certain level, for example anything lower than -70LUFS (dB) can be ignored. However, a Gate is not used in ‘M’ and ‘S’ measurements. It is applicable to the ‘I’ measurement.
‌Scales – An ‘EBU Mode’ meter shall offer two scales, for when a scale is shown, selectable by the user: range -18.0 LU to +9.0 LU (-41.0 LKFS to -14.0 LKFS), named ‘EBU +9 scale’ or range -36.0 LU to +18.0 LU (-59.0 LKFS to -5.0 LKFS), named ‘EBU +18 scale’
Live Meter – In an ‘EBU Mode’ ‘live meter’ all three time scales shall be available, but not necessarily displayed at the same time.
Non Live Meter – Is used for example in the case of a file-based software meter, which measures average loudness of a given programme, in compliance with the ‘EBU Mode’ requirements.
Maximum Loudness – The loudness meter shall be able to display the maximum value of the ‘momentary loudness’. This maximum value is reset when the integrated loudness measurement is reset.