Sunday, January 24, 2016

Loudness

So a thing which concerns me is that I think in the future we're going to start seeing demands for ATSC A/85 loudness standards in deliverables.
But we do care. We care so much.

Now for them of us in the indy world, there's frequently some allowances for certain standards which exist in the big network TV world which we get to slide by. But I don't think the international loudness standards are going to be one of those things.
So I want to be ahead of the... 8-ball? Curve? Whatever it is one needs to be ahead of to make sure we're delivering masters which are compliant to CALM act and that sort of thing.
The high-end version of the audio mixing/editing software I use (Samplitude) is called Sequoia. It is comically expensive (almost $3000). But it has built-in tools for decent loudness metering.
There are cheaper LUFS meters, but not necessarily what one is looking for in the way of broadcast audio.
In any case, measuring A/85 or any of the other loudness standards is... weird. You're measuring an average of an average of a level but only within a certain frequency range and only when the signal is above a certain level. Right? Because loudness is a subjective thing and making a meter to measure it is a pain in the tuchus.
Dig this (from the above TC Electronics link):
Target levels are specified in various broadcast standards, but only vary slightly. For instance, the ATSC A/85 standard recommends a target of -24 and uses the LKFS term, whereas the EBU R128 standard sets the target level at -23 and uses the LUFS term. One of the reasons for this difference is that the R128 standard employs the above-mentioned gate, which in effect makes most measurements equivalent to -24 LKFS/LUFS without the gate - yet more useful for aligning loudness across genres.
Yup. The broadcast standards are sort of difficult to get one's head around. But it's doable. And if we can guarantee the deliverables (which I imagine might be important for VOD) it will help.

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