PAO Spectrum

Finished Audio Unit for Logic Pro 9 on Mac OS X 10.5.8 (i386).

Mirrored white spectrum on a black 640x480 window for an external monitor on the master / stereo out. Audio passes through unchanged.

Built for Procesos Analogicos de Occidente (vinyl cutting).

Validated with auval and used in Logic on the cutting-room iMac.

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Install (recommended)

Download the prebuilt component from the latest release:

PAO-Spectrum-1.0.0-Logic9-i386.component.zip

All releases: https://github.com/fabdelamora/PAO-Spectrum-Xcode3/releases

1. Unzip PAO-Spectrum-1.0.0-Logic9-i386.component.zip

2. Copy PAO Spectrum.component to:

   ~/Library/Audio/Plug-Ins/Components/
   

   (or /Library/Audio/Plug-Ins/Components/)

3. Restart Logic 9

4. Stereo Out > Insert > Audio Units > Procesos Analogicos > PAO Spectrum

Optional check:

auval -v aufx SpcM PAnA
# should end with: AU VALIDATION SUCCEEDED

Field	FourCC
Type	aufx
Subtype	SpcM
Manufacturer	PAnA

Parameter Altura (0.25-4.0): how high the bars reach. Display only; does not change audio.

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Source code

This repository is the full Xcode 3.1.4 project used to build that component (Core Audio SDK + Leopard shims included). Use it if you want to change the look, rebuild, or hack on it.

Piece	Version
OS	Mac OS X 10.5.8
Xcode	3.1.4 (not 3.2.x)
Arch	i386

Build from source (iMac)

1. Open PAO Spectrum.xcodeproj
2. Configuration: Release
3. Build > Clean All, then Build (Cmd+B)
4. Install build/Release/PAO Spectrum.component as above

Short Spanish notes: LEEME.txt

Repository layout

PAO-Spectrum-Xcode3/
|-- README.md
|-- LEEME.txt
|-- LICENSE / NOTICE
|-- exports.exp
|-- PAO Spectrum.xcodeproj/
|-- Resources/Info.plist
|-- Source/                 # plugin DSP + Cocoa UI
|-- SDK/                    # CoreAudioSDK + LeopardShims
`-- tools/

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Customize the view

Almost all visual changes live in Source/CocoaUI/SpectrumView.m.
Window size is set in Source/CocoaUI/SpectrumViewFactory.m.
Bar count / FFT live in Source/PAOSpectrum.h (+ matching kNumBars in the view).

Window size (640x480)

Source/CocoaUI/SpectrumViewFactory.m:

NSRect frame = NSMakeRect (0, 0, 640, 480);

Change 640 / 480 for another fixed size.

Colors and bar look

In SpectrumView.m ? -drawRect::

What	Where
Background	[[NSColor blackColor] set]; then NSRectFill (bounds);
Bar color	[[NSColor whiteColor] set]; before drawing bars
Margins	padX, padTop, padBottom
Bar thickness	barW = slotW * 0.42f (raise toward 1.0 for thicker bars)
Mirror	bars are drawn as centreY - halfH - remove the lower half for a single-sided meter

Example - dark red bars on near-black:

[[NSColor colorWithCalibratedRed:0.05f green:0.05f blue:0.05f alpha:1.0f] set];
NSRectFill (bounds);
/* ... */
[[NSColor colorWithCalibratedRed:0.85f green:0.15f blue:0.12f alpha:1.0f] set];

Refresh rate

In -initWithFrame:audioUnit::

mTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 / 45.0 ...

45.0 is frames per second. Lower = less CPU; higher = smoother.

Number of bars

1. Source/PAOSpectrum.h ? kNumberOfBars = 64
2. Source/CocoaUI/SpectrumView.m ? kNumBars = 64 (must match)
3. Source/CocoaUI/SpectrumView.h ? float mBars[64]; (same size)

FFT resolution: kFFTOrder / kFFTSize in PAOSpectrum.h.

Hide or restyle the Altura slider

Still in SpectrumView.m -initWithFrame:audioUnit: (slider creation) and the "altura" label in -drawRect:.

Parameter range is defined in PAOSpectrum.cpp ? GetParameterInfo (minValue / maxValue / name "Altura").

After changing the view

Rebuild Release on the iMac, reinstall the .component, restart Logic.

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Troubleshooting (rebuild)

Symptom	Check
Only "Apple" under Audio Units	.rsrc must declare i386 (i386_YES in PAOSpectrum.r)
Logic: "Incompatible Audio Units"	Run auval -v aufx SpcM PAnA
Version mismatch Res/Comp	Version() must return 0x00010000
Linker: _PAOSpectrumEntry: No such file	EXPORTED_SYMBOLS_FILE = exports.exp
Tiny ~24 KB binary, no Entry	DEAD_CODE_STRIPPING = NO + exports.exp

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License

This repo has two license scopes:

Path	License
Source/, Resources/, SDK/LeopardShims/, tools/, project, docs/, README	MIT - see LICENSE
SDK/CoreAudioSDK/	Apple sample-code terms - see NOTICE and headers in that tree

The prebuilt .component in the release mixes both: your use of the plugin binary is fine under normal AU use; if you redistribute source that still contains SDK/CoreAudioSDK/, keep Apple's notices.