Application Note: Audio Loudness Applied in the Broadcast Chain (2.3MB)
Audio Loudness problems are nothing new. For years broadcasters have had the challenge of providing audio and video content to their target audience while minimizing complaints about the drastic variations in audio loudness between program and commercial.
There are two main complaints
1. Commercial Loudness
2. Channel to Channel loudness variation.
As more and more channels with inconsistent audio levels are distributed to the home, public annoyance has increased. Some recent studies have shown up to a 17dB deviation in perceived loudness of programming between channels. Home listeners have had to tolerate this problem by either muting the commercials or adjusting the volume as they watch their programs.
Evertz has recognized this dilemma and presents its patented IntelliGain® as the solution
This patented technology can be applied to a number of Evertz products, including frame synchronizers, protection switches, audio embedders and de-embedders just to name a few.
- Consistent audio loudness levels within a channel and/or program
- Automatic detection and level adjust for loud commercials
- Gain control within a program interval to preserve audio dynamic range
- Artifact-free transitions between program and commercials
- Elimination of drastic volume changes during commercials and interstitials
- Fully Integrated Dynamic Range Processor, also referred to as a compander
- Ideal for aggregator applications and multi-channel playout facilities (DTH, Cable, IPTV...)
- VistaLINK® controlled and monitored!
IntelliGain® processes long term trends in the audio content and uses a multi-minute time coefficient, which applies a smooth attack producing the final target loudness output. IntelliGain® processes audio programs of various or mixed configurations, such as mono, stereo, or multi-channel. When coupled with an Evertz audio product that is equipped with a Dolby decoder, IntelliGain® can extract program configuration information from Dolby E or AC-3 stream and configure itself accordingly to account for a multi-channel arrangement.
IntelliGain® also incorporates an onboard Compressor, Peak Limiter and Expander, also referred to as a compander, for professional Dynamic Range Processing. The use of the compander lends perfectly to many and can be locally enabled or disabled depending on the application requirement. The compander can be configured to apply different profiles based on the content type to ensure optimum dynamic range processing.
VistaLINK® enables control and configuration capabilities via Simple Network Management Protocol (SNMP). This offers the flexibility to manage the module status monitoring and configuration locally or remotely.
|Notes||• +IG must be specified at time of order with supporting product - eg: [model]+IG|
|+IG||IntelliGain® Inter-Program and Intra-Program Loudness Control|
|500IDA9-IG||SD-SDI Intelligent 1x9 Distribution Amplifier with IntelliGain|
|7800IDA8-3G||3G/HD/SD-SDI Intelligent 1x8 Distribution Amplifier|
|7700ACO2-HD||Dual HD/SD-SDI Smart Automatic Changeover|
|7812UDX-3G||3G/Hd Up/Down/Cross Converter with Optional AES and/or Fiber I/O|
|VLPRO-IG||Standalone IntelliGain Monitoring and Graphing Software Application|
See the full list of products supporting IntelliGain®