Intelligain Overview - evertz 7812UDXD Series Manual

6.47.

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 8 programs simultaneously.
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.
An important feature that IntelliGain possesses is its ability to automatically detect commercials/promos
and normal programs. During commercial/promo periods, it uses one set of attack and release times, and
during normal program periods, it uses another set of attack and release times. Both sets of attack and
release times are definable by the user. In general, it is desirable to have faster attack/release times for
commercial/promo periods and slower attack/release times for normal program periods. The level
adjustment at the transition from one program/commercial to the next is almost instant, but it is not
audible. While within a program or commercial, the adjustment is slow to maintain the dynamic range of
the material.
Features:
•
Normalize loudness of audio programs to a target level
•
Peak limiting
•
Automatic detection of loud commercials or programs
•
Relatively constant gain within a program interval to preserve audio dynamic range
•
Artifact-free transition between programs and commercials
•
Automatic configuration of audio programs according to input Dolby E or AC-3 stream
•
Simultaneously process multiple multi-channel programs
•
User adjustable attack and release times
7812UDXD Series 3G/HD Up/Down/Cross Converter with Simultaneous Dual Format Outputs and AES I/O
Revision 1.1.1
7800/7700 MultiFrame Manual
The objective
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