Intelligain Overview - evertz MultiFrame 7814 Series User Manual

7.23. INTELLIGAIN OVERVIEW

IntelliGain is a technology developed by Evertz to control the loudness of audio programs on the fly.
More specifically, it calculates the perceived loudness of the input audio and modifies the audio to ensure
that the long-term average loudness level is at the target level. IntelliGain works with mono, stereo and
multi-channel audio per program and can handle up to 16 programs simultaneously. The objective
loudness calculation is based on ITU Recommendation (ITU-R BS.1770), "Algorithms to measure audio
program loudness and true-peak audio level". This recommendation provides equations for calculating
loudness over mono, stereo and multi-channel audio programs. IntelliGain constantly calculates audio
program loudness. When the loudness is over the target level, it reduces the gain; and when the loudness
is below the target level, it increases the gain. The gain adjustment smoothness is user-controllable by
setting attack and release times.
Features:
•
Normalize loudness of audio programs to a target level
•
Supports up to 16 programs and 16 channels
•
Relatively constant gain within a program interval to preserve audio dynamic range
•
Simultaneously process multiple multi-channel programs
•
User adjustable attack and release times
•
Applied loudness algorithm ITU-R BS. 1770
•
Peak limiting
•
LKFS calculations
•
Momentary, short term and integrated loudness measurements
7800/7700 MultiFrame Manual
7814 Series Dual HDTV Up/Down/Cross Converters
Revision 1.1.3
Page - 109