
The VU Meter and How It Got That Way - sohkamyung
https://hackaday.com/2018/08/09/the-vu-meter-and-how-it-got-that-way/
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squarefoot
For those interested, Tonne Software
([http://www.tonnesoftware.com/](http://www.tonnesoftware.com/)) among some
other programs made a software to draw personalized meter scales.
Unfortunately not open source but worth a look nonetheless.

I would love a library to implement virtual instruments (VU meters, ammeters,
voltmeters, scales etc.) using most common graphic libraries, that is, an
instrument "component" with a set of rules for its needle min-max values,
speed, ratio, inertia etc, and some nicely drawn needles and background
usages/styles to replicate vintage or modern instruments. I admit having tried
ages ago to do something similar in Delphi, a radio virtual scale, but failed
badly: In my approach I tried to move the background (a scanned replica of a
real radio scale) under a smaller window with fixed needle, but smoothness was
terrible. Animating the needle would probably have been easier.

~~~
jacquesm
I built just that but for a platform that is no longer usable (Borland C++
builder). The whole idea of re-usable components like that which you include
in your product linked along with the rest of the code was very appealing,
much more so than today's 'include this javascript from some server
somewhere'. At least we now have subsource integrity.

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klodolph
Note that there have been some recent changes—we now have LKFS, or LUFS,
whatever you want to call it. There are now a set of standards for how to
compare the loudness of different programs.

[https://en.m.wikipedia.org/wiki/LKFS](https://en.m.wikipedia.org/wiki/LKFS)

Nowadays there are enough systems out there that will clamp down on LUFS to
some value like -14 that it’s taking away incentives for people to slam their
mixes into the wall. Spotify does this. If your music is -8 LUFS the Spotify
attenuates it by -6.

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antonyme
Unfortunately, the majority of technical details on the web on implementing VU
meters in the digital domain is misleading, of not outright wrong.

A while back, I implemented VU meters for some professional AV software. I
started with the available references, but quickly discovered that it was
well-intentioned but incorrect/inaccurate. I ended up sourcing the original
specification for the analog meters, and then devising digital filters to
replicate the same ballistics. This matched perfectly with the reference, (pro
hardware).

TL;DR don't believe what you read on the web. Go to primary sources!

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esaym
Now I miss my old stereo...

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agumonkey
Damn, I always wondered why led based vu meters had this smooth lag.

