VUMeter

VU 53.2 (10/31/2021)
©31.10.2021 Lyle Hazelwood, all rights reserved

A simple Audio Level Meter


Displays Audio Level information on a 2 channel vertical bargraph display.
Configurable size, color, and ballistics.

Gets audio level information by CAMD, using MIDI messages.

There are new X1000 and A1222 audio drivers that can provide these 
messages if enabled. These are not yet been distributed, but they are coming.


/**************** Quick Start: *********************/
Copy VU to wherever you want it.

For the AHI drivers,
Enable the data stream by typing the following line into a shell:
Setenv SAVE sys/vumeter VU
reboot, or run VU from workbench or shell or user-startup or however you want.
play anything that makes sound through AHI

For recording level, use the arg or tooltype FIRSTCHANNEL 13

For other programs like USBAudio2, you open the meter with whatever name
you choose, then specify that name with the METER arg of USBAudio2.

My own user-startup file includes the following two lines:
run >nil: <nil: userc:VU L 1900 T 50 W 32 H 900 B 0x00000000 F 0x00FF0000 VU
run >nil: <nil: userc:VU L 1827 T 50 W 32 H 900 B 0x00000000 F 0x00FF0000 I
HD404 C 4

The first line opens a tall, narrow 2 channel meter with red on black, on the
right 
edge of a 1080p workbench screen. My VU executable is in userc:, and the
ballistics
will emulate a VU meter. name is the default "VU" (not specified)

Just inboard of that is a similar 4 channel meter with no damping (very fast
response)
named HD404. This one is for my UM404HD USB audio interface.

FYI, these are properly "event driven". When there's no activity, there's no
load
on the system. And when there IS activity, the load is quite light.


/*********** Command Line Options: VU ? *****************/

L=LEFTEDGE/N,T=TOPEDGE/N,W=WIDTH/N,H=HEIGHT/N,P=PUBSCREEN/K,
V=VERBOSE/S,I=INLINKNAME/K,B=BACKGROUND/K,F=FOREGROUND/K,
LEGENDS/S,VU/S,DAMPINGUP/N,DAMPINGDOWN/N,FIRSTCHANNEL/N,
LOWMETER/N,HIGHMETER/N: 

L=LEFTEDGE/N,T=TOPEDGE/N,W=WIDTH/N,H=HEIGHT/N:
These four numbers control where the window will open on your screen.
You may use the full name or the first letter for each.
Example:
VU L 100 T 100 W 50 H 300
opens VU with a medium size near your upper-left screen corner
VU LEFTEDGE 100 TOPEDGE 100 WIDTH 75 HEIGHT 300
Just the same, but a little bit wider
The defaults for these are LEFTEDGE 0 TOPEDGE 0 WIDTH 0 HEIGHT 0
which opens as small as possible in the upper left corner of your screen.

P=PUBSCREEN/K
Tells VU to open on the named Public screen. Default is "Workbench" (untested)

V=VERBOSE
If this keyword is present, VU will print out details when running. most
notably it will echo all startup options found. Default is FALSE

I=INLINKNAME
tells VU which CAMD cluster name to get audio level data from. 
Default is "VU". Note: CAMD link names are CASEseNsitive!

B=BACKGROUND/K,F=FOREGROUND/K
These set the color of your Meter The format for both is an "ARGB Hex string".
This is an eight digit string, made up of four pairs. Often preceeded by 0x.
The first pair is..?? maybe transparency?? I don't know. I always use zero.
The next pair is Red, then the Green pair, then the Blue pair.
For each pair, the lowest number possible is 00 and the highest is FF.
Some examples:
BLACK 0x00000000
RED   0x00FF0000
GREEN 0x0000FF00
BLUE  0x000000FF
GRAY  0x00777777
WHITE 0x00FFFFFF
Obviously there are millions of possible combinations. Experiment.
Default is dark background , White foreground. (BORING!)

Legends/S
If this keyword is present, deciBel levels will be printed beside the meter,
to show exactly what your levels are. So far I have not implemented this, So 
if it's not working, I am personally to blame. Default is FALSE

VU/S
This will preset the damping to resemble a "proper" audio VU meter. You may
adjust the damping further with the next two options if you like.
Default is FALSE

DAMPINGUP/N,DAMPINGDOWN/N
These slow down the meter response, to better show average levels. Higher
damping numbers make the meter move slower in that direction. Damping 0
moves at full speed (default) maximum (slowest) damping is 255. The VU option 
presets DAMPINGUP to 240, DAMPINGDOWN to 150. These fairly approximate a real
VU meter. NOTE: If you are watching for PEAK levels, Damping up is not a  good 
idea. short peaks are "hidden" by damping up. Default is 0

FIRSTCHANNEL/N
The A1222 and X-1000 audio drivers encode the playback audio data into 
notes 1(Left) and 2(Right). Input levels are in notes 13(L) and 14(R)
I left note zero for Monophonic use (but who uses Mono, really??)
So to watch playback the Default 1 is correct. To watch recording levels,
set FIRSTCHANNEL to 13

LOWMETER/N,HIGHMETER/N
These let you display a smaller section of the full 0-127 meter range.

At full range, the meter displays down to about -32 dB, which is more 
sensitive than most VU meters, and likely too sensitive to hear on consumer 
grade speakers. Every point your LOWMETER raises above zero will trim 0.25 
deciBel off the bottom of the displayed range.

Reducing HIGHMETER will cause the meter to hit the top before full volume.
Which is probably a lot less useful than the LOWMETER adjustment.

..... more in VU.readme file