Added FFT sound visualization

CaseLights/AppDelegate.h

 
 @interface AppDelegate : NSObject <NSApplicationDelegate, EZMicrophoneDelegate>
 
+@property (weak) IBOutlet NSApplication *application;
+
+@property (strong) EZMicrophone *microphone;
+
 - (void)clearDisplayUI;
 - (void)updateDisplayUI:(NSArray *)displayIDs;
 
 - (void)setLightsR:(unsigned char)r G:(unsigned char)g B:(unsigned char)b;
 
++ (double)map:(double)val FromMin:(double)fmin FromMax:(double)fmax ToMin:(double)tmin ToMax:(double)tmax;
++ (void)convertH:(double)h S:(double)s V:(double)v toR:(unsigned char *)r G:(unsigned char *)g B:(unsigned char *)b;
+
 @end
 

CaseLights/AppDelegate.m

 @interface AppDelegate ()
 
 @property (weak) IBOutlet NSMenu *statusMenu;
-@property (weak) IBOutlet NSApplication *application;
 
 @property (weak) IBOutlet NSMenu *menuColors;
 @property (weak) IBOutlet NSMenu *menuAnimations;
 @property (strong) NSTimer *animation;
 @property (strong) Serial *serial;
 @property (strong) NSMenuItem *lastLEDMode;
-@property (strong) EZMicrophone *microphone;
 
 @end
 
     [application orderFrontStandardAboutPanel:self];
 }
 
-- (void)updateBuffer:(float *)buffer withBufferSize:(UInt32)bufferSize {
-    if (microphone == nil) {
-        return; // Old buffer from before we changed mode
-    }
-    
-    [AudioVisualizer updateBuffer:buffer withBufferSize:bufferSize];
-}
-
 // ------------------------------------------------------
 // ----------------- Microphone Delegate ----------------
 // ------------------------------------------------------
     // EZAudioPlot, EZAudioPlotGL, or whatever visualization you would like to do with
     // the microphone data.
     dispatch_async(dispatch_get_main_queue(),^{
+        if (weakSelf.microphone == nil) {
+            return;
+        }
+        
         // buffer[0] = left channel, buffer[1] = right channel
-        [weakSelf updateBuffer:buffer[0] withBufferSize:bufferSize];
+        [AudioVisualizer updateBuffer:buffer[0] withBufferSize:bufferSize];
     });
 }
 
     if ([GPUStats getGPUUsage:&usage freeVRAM:&freeVRAM usedVRAM:&usedVRAM] != 0) {
         NSLog(@"Error reading GPU information\n");
     } else {
-        double h = [self map:[usage doubleValue] FromMin:0.0 FromMax:100.0 ToMin:GPU_COLOR_MIN ToMax:GPU_COLOR_MAX];
+        double h = [AppDelegate map:[usage doubleValue] FromMin:0.0 FromMax:100.0 ToMin:GPU_COLOR_MIN ToMax:GPU_COLOR_MAX];
         
 #ifdef DEBUG
         NSLog(@"GPU Usage: %.3f%%\n", [usage doubleValue]);
 #endif
         
         unsigned char r, g, b;
-        [self convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
+        [AppDelegate convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
         [self setLightsR:r G:g B:b];
     }
 }
     if ([GPUStats getGPUUsage:&usage freeVRAM:&freeVRAM usedVRAM:&usedVRAM] != 0) {
         NSLog(@"Error reading GPU information\n");
     } else {
-        double h = [self map:[freeVRAM doubleValue] FromMin:0.0 FromMax:([freeVRAM doubleValue] + [usedVRAM doubleValue]) ToMin:RAM_COLOR_MIN ToMax:RAM_COLOR_MAX];
+        double h = [AppDelegate map:[freeVRAM doubleValue] FromMin:0.0 FromMax:([freeVRAM doubleValue] + [usedVRAM doubleValue]) ToMin:RAM_COLOR_MIN ToMax:RAM_COLOR_MAX];
         
 #ifdef DEBUG
         NSLog(@"VRAM %.2fGB Free + %.2fGB Used = %.2fGB mapped to color %.2f!\n", [freeVRAM doubleValue] / (1024.0 * 1024.0 * 1024.0), [usedVRAM doubleValue] / (1024.0 * 1024.0 * 1024.0), ([freeVRAM doubleValue] + [usedVRAM doubleValue]) / (1024.0 * 1024.0 * 1024.0), h);
 #endif
         
         unsigned char r, g, b;
-        [self convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
+        [AppDelegate convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
         [self setLightsR:r G:g B:b];
     }
 }
 - (void)visualizeCPUUsage:(NSTimer *)timer {
     JSKMCPUUsageInfo cpuUsageInfo = [JSKSystemMonitor systemMonitor].cpuUsageInfo;
     
-    double h = [self map:cpuUsageInfo.usage FromMin:0.0 FromMax:100.0 ToMin:CPU_COLOR_MIN ToMax:CPU_COLOR_MAX];
+    double h = [AppDelegate map:cpuUsageInfo.usage FromMin:0.0 FromMax:100.0 ToMin:CPU_COLOR_MIN ToMax:CPU_COLOR_MAX];
     
 #ifdef DEBUG
     NSLog(@"CPU Usage: %.3f%%\n", cpuUsageInfo.usage);
 #endif
     
     unsigned char r, g, b;
-    [self convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
+    [AppDelegate convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
     [self setLightsR:r G:g B:b];
 }
 
 - (void)visualizeRAMUsage:(NSTimer *)timer {
     JSKMMemoryUsageInfo memoryUsageInfo = [JSKSystemMonitor systemMonitor].memoryUsageInfo;
     
-    double h = [self map:memoryUsageInfo.freeMemory FromMin:0.0 FromMax:(memoryUsageInfo.usedMemory + memoryUsageInfo.freeMemory) ToMin:RAM_COLOR_MIN ToMax:RAM_COLOR_MAX];
+    double h = [AppDelegate map:memoryUsageInfo.freeMemory FromMin:0.0 FromMax:(memoryUsageInfo.usedMemory + memoryUsageInfo.freeMemory) ToMin:RAM_COLOR_MIN ToMax:RAM_COLOR_MAX];
     
 #ifdef DEBUG
     NSLog(@"RAM %.2fGB Free + %.2fGB Used = %.2fGB mapped to color %.2f!\n", memoryUsageInfo.freeMemory / (1024.0 * 1024.0 * 1024.0), memoryUsageInfo.usedMemory / (1024.0 * 1024.0 * 1024.0), (memoryUsageInfo.freeMemory + memoryUsageInfo.usedMemory) / (1024.0 * 1024.0 * 1024.0), h);
 #endif
     
     unsigned char r, g, b;
-    [self convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
+    [AppDelegate convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
     [self setLightsR:r G:g B:b];
 }
 
         temp = GPU_TEMP_MIN;
     }
     
-    double h = [self map:temp FromMin:GPU_TEMP_MIN FromMax:GPU_TEMP_MAX ToMin:GPU_COLOR_MIN ToMax:GPU_COLOR_MAX];
+    double h = [AppDelegate map:temp FromMin:GPU_TEMP_MIN FromMax:GPU_TEMP_MAX ToMin:GPU_COLOR_MIN ToMax:GPU_COLOR_MAX];
     
 #ifdef DEBUG
     NSLog(@"GPU Temp %.2f mapped to color %.2f!\n", temp, h);
 #endif
     
     unsigned char r, g, b;
-    [self convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
+    [AppDelegate convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
     [self setLightsR:r G:g B:b];
 }
 
         temp = CPU_TEMP_MIN;
     }
     
-    double h = [self map:temp FromMin:CPU_TEMP_MIN FromMax:CPU_TEMP_MAX ToMin:CPU_COLOR_MIN ToMax:CPU_COLOR_MAX];
+    double h = [AppDelegate map:temp FromMin:CPU_TEMP_MIN FromMax:CPU_TEMP_MAX ToMin:CPU_COLOR_MIN ToMax:CPU_COLOR_MAX];
     
 #ifdef DEBUG
     NSLog(@"CPU Temp %.2f mapped to color %.2f!\n", temp, h);
 #endif
     
     unsigned char r, g, b;
-    [self convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
+    [AppDelegate convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
     [self setLightsR:r G:g B:b];
 }
 
     }
     
     unsigned char r, g, b;
-    [self convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
+    [AppDelegate convertH:h S:1.0 V:1.0 toR:&r G:&g B:&b];
     [self setLightsR:r G:g B:b];
 }
 
 // --------------------- Utilities ---------------------
 // -----------------------------------------------------
 
-- (double)map:(double)val FromMin:(double)fmin FromMax:(double)fmax ToMin:(double)tmin ToMax:(double)tmax {
++ (double)map:(double)val FromMin:(double)fmin FromMax:(double)fmax ToMin:(double)tmin ToMax:(double)tmax {
     double norm = (val - fmin) / (fmax - fmin);
     return (norm * (tmax - tmin)) + tmin;
 }
 
-- (void)convertH:(double)h S:(double)s V:(double)v toR:(unsigned char *)r G:(unsigned char *)g B:(unsigned char *)b {
++ (void)convertH:(double)h S:(double)s V:(double)v toR:(unsigned char *)r G:(unsigned char *)g B:(unsigned char *)b {
     // Adapted from:
     // https://gist.github.com/hdznrrd/656996
     

CaseLights/AudioVisualizer.m

 //  AudioVisualizer.m
 //  CaseLights
 //
+//  Based on the ideas in:
+//  http://archive.gamedev.net/archive/reference/programming/features/beatdetection/
+//
+//  The detected sound frequency of beats will be mapped to the hue of the resulting color,
+//  the variance of the beat is mapped to the brightness of the color. The colors
+//  of all detected beats will be added together to form the final displayed color.
+//
 //  Created by Thomas Buck on 01.01.16.
 //  Copyright © 2016 xythobuz. All rights reserved.
 //
 
+// Enabling this will cause crashes when changing audio input
+// devices while the app is running. Select it before enabling.
+#define DEBUG_PLOT_FFT
+//#define DEBUG_PLOT_FFT_RAW
+
+#define DEBUG_LOG_BEATS
+
 #import "AudioVisualizer.h"
 #import "AppDelegate.h"
 
+#import "EZAudioFFT.h"
+
+#ifdef DEBUG_PLOT_FFT
+#import "EZAudioPlot.h"
+#endif
+
+// Parameters for fine-tuning beat detection
+#define FFT_BUCKET_COUNT 64
+#define FFT_BUCKET_HISTORY 43
+#define FFT_C_FACTOR 4.2
+#define FFT_V0_FACTOR 0.000015
+#define FFT_MAX_V0_COLOR 0.0002
+#define FFT_COLOR_DECAY 0.99
+
+// Factors for nicer debug display
+#define FFT_DEBUG_RAW_FACTOR 42.0
+#define FFT_DEBUG_FACTOR 230.0
+
 static AppDelegate *appDelegate = nil;
+static EZAudioFFT *fft = nil;
+static int maxBufferSize = 0;
 
 @implementation AudioVisualizer
 
 }
 
 + (void)updateBuffer:(float *)buffer withBufferSize:(UInt32)bufferSize {
+    // Create Fast Fourier Transformation object
+    if (fft == nil) {
+        maxBufferSize = bufferSize;
+        fft = [EZAudioFFT fftWithMaximumBufferSize:maxBufferSize sampleRate:appDelegate.microphone.audioStreamBasicDescription.mSampleRate];
+        
+#ifdef DEBUG
+        NSLog(@"Created FFT with max. freq.: %.2f\n", appDelegate.microphone.audioStreamBasicDescription.mSampleRate / 2);
+#endif
+    }
+    
+    // Check for changing buffer sizes
+    if (bufferSize > maxBufferSize) {
+        NSLog(@"Buffer Size changed?! %d != %d\n", maxBufferSize, bufferSize);
+        maxBufferSize = bufferSize;
+        fft = [EZAudioFFT fftWithMaximumBufferSize:maxBufferSize sampleRate:appDelegate.microphone.audioStreamBasicDescription.mSampleRate];
+    }
+    
+    [fft computeFFTWithBuffer:buffer withBufferSize:bufferSize];
+    
+    static float history[FFT_BUCKET_COUNT][FFT_BUCKET_HISTORY];
+    static int nextHistory =  0;
+    static int samplesPerBucket = 0;
+    
+    // Initialize static variables
+    if (samplesPerBucket == 0) {
+        samplesPerBucket = bufferSize / FFT_BUCKET_COUNT;
+        for (int i = 0; i < FFT_BUCKET_COUNT; i++) {
+            for (int j = 0; j < FFT_BUCKET_HISTORY; j++) {
+                history[i][j] = 0.5f;
+            }
+        }
+    }
+    
+    // Split FFT output into a small number of 'buckets' or 'bins' and add to circular history buffer
+    for (int i = 0; i < FFT_BUCKET_COUNT; i++) {
+        float sum = 0.0f;
+        for (int j = 0; j < samplesPerBucket; j++) {
+            sum += fft.fftData[(i + samplesPerBucket) + j];
+        }
+        history[i][nextHistory] = sum / samplesPerBucket;
+    }
+    
+#ifdef DEBUG_PLOT_FFT
+    int beatCount = 0;
+#endif
+    
+    static unsigned char lastRed = 0, lastGreen = 0, lastBlue = 0;
+    lastRed = lastRed * FFT_COLOR_DECAY;
+    lastGreen = lastGreen * FFT_COLOR_DECAY;
+    lastBlue = lastBlue * FFT_COLOR_DECAY;
+    
+    // Check for any beats
+    for (int i = 0; i < FFT_BUCKET_COUNT; i++) {
+        float average = 0.0f;
+        for (int j = 0; j < FFT_BUCKET_HISTORY; j++) {
+            average += history[i][j];
+        }
+        average /= FFT_BUCKET_HISTORY;
+        float v = 0.0f;
+        for (int j = 0; j < FFT_BUCKET_HISTORY; j++) {
+            float tmp = history[i][j] - average;
+            tmp *= tmp;
+            v += tmp;
+        }
+        v /= FFT_BUCKET_HISTORY;
+        if ((history[i][nextHistory] > (FFT_C_FACTOR * average)) && (v > FFT_V0_FACTOR)) {
+            // Found a beat on this frequency band, map to a single color
+            if (v < FFT_V0_FACTOR) v = FFT_V0_FACTOR;
+            if (v > FFT_MAX_V0_COLOR) v = FFT_MAX_V0_COLOR;
+            float bright = [AppDelegate map:v FromMin:FFT_V0_FACTOR FromMax:FFT_MAX_V0_COLOR ToMin:0.0 ToMax:100.0];
+            float hue = [AppDelegate map:i FromMin:0.0 FromMax:FFT_BUCKET_COUNT ToMin:0.0 ToMax:360.0];
+            unsigned char r, g, b;
+            [AppDelegate convertH:hue S:1.0 V:bright toR:&r G:&g B:&b];
+            
+            // Blend with last color using averaging
+            int tmpR = (lastRed + r) / 2;
+            int tmpG = (lastGreen + g) / 2;
+            int tmpB = (lastBlue + b) / 2;
+            lastRed = tmpR;
+            lastGreen = tmpG;
+            lastBlue = tmpB;
+            
+#ifdef DEBUG_LOG_BEATS
+            NSLog(@"Beat in %d with c: %f v: %f", i, (history[i][nextHistory] / average), v);
+#endif
+#ifdef DEBUG_PLOT_FFT
+            beatCount++;
+#endif
+        }
+    }
+    
+    [appDelegate setLightsR:lastRed G:lastGreen B:lastBlue];
+
+#ifdef DEBUG_PLOT_FFT
+    static NSWindow *window = nil;
+    static EZAudioPlot *plot = nil;
+    static NSTextField *label = nil;
+    if ((window == nil) || (plot == nil) || (label == nil)) {
+        NSRect frame = NSMakeRect(450, 300, 600, 400);
+        window = [[NSWindow alloc] initWithContentRect:frame
+                                             styleMask:NSClosableWindowMask | NSTitledWindowMask | NSBorderlessWindowMask
+                                               backing:NSBackingStoreBuffered
+                                                 defer:NO];
+        [window setTitle:@"Debug FFT"];
+        
+        plot = [[EZAudioPlot alloc] initWithFrame:window.contentView.frame];
+        plot.color = [NSColor whiteColor];
+        plot.shouldOptimizeForRealtimePlot = NO; // Not working with 'YES' here?!
+        plot.shouldFill = YES;
+        plot.shouldCenterYAxis = NO;
+        plot.shouldMirror = NO;
+        plot.plotType = EZPlotTypeBuffer;
+        [window.contentView addSubview:plot];
+        
+        label = [[NSTextField alloc] initWithFrame:NSMakeRect(0, 380, 600, 20)];
+        [label setTextColor:[NSColor whiteColor]];
+        [label setEditable:NO];
+        [label setBezeled:NO];
+        [label setDrawsBackground:NO];
+        [label setSelectable:NO];
+        [label setStringValue:@"-"];
+        [window.contentView addSubview:label];
+        
+        [window makeKeyAndOrderFront:appDelegate.application];
+        NSLog(@"Created debugging FFT Plot window...\n");
+    }
+    
+    // Scale so we can see something
+# ifdef DEBUG_PLOT_FFT_RAW
+    memcpy(buffer, fft.fftData, bufferSize * sizeof(float));
+    for (UInt32 i = 0; i < bufferSize; i++) {
+        buffer[i] *= FFT_DEBUG_RAW_FACTOR;
+# else
+    for (int i = 0; i < FFT_BUCKET_COUNT; i++) {
+        buffer[i] = history[i][nextHistory];
+    }
+    for (UInt32 i = 0; i < FFT_BUCKET_COUNT; i++) {
+        buffer[i] *= FFT_DEBUG_FACTOR;
+# endif
+        if (buffer[i] > 1.0f) buffer[i] = 1.0f;
+        if (buffer[i] < -1.0f) buffer[i] = -1.0f;
+    }
+    [plot updateBuffer:buffer withBufferSize:bufferSize];
     
+    [window setBackgroundColor:[NSColor colorWithCalibratedRed:lastRed / 255.0 green:lastGreen / 255.0 blue:lastBlue / 255.0 alpha:1.0]];
+    [label setStringValue:[NSString stringWithFormat:@"Beats: %d", beatCount]];
+#endif
+        
+    // Point to next history buffer
+    nextHistory++;
+    if (nextHistory >= FFT_BUCKET_HISTORY) {
+        nextHistory = 0;
+    }
 }
 
 @end

CaseLights/Info.plist

 	<key>CFBundleSignature</key>
 	<string>????</string>
 	<key>CFBundleVersion</key>
-	<string>182</string>
+	<string>359</string>
 	<key>LSApplicationCategoryType</key>
 	<string>public.app-category.utilities</string>
 	<key>LSMinimumSystemVersion</key>

CaseLights/Serial.m

 //  Copyright © 2015 xythobuz. All rights reserved.
 //
 
+//#define DEBUG_TEXT
+
 #import <Cocoa/Cocoa.h>
 #import <IOKit/IOKitLib.h>
 #import <IOKit/serial/IOSerialKeys.h>
     const char *data = [string UTF8String];
     size_t length = strlen(data);
     
-#ifdef DEBUG
+#ifdef DEBUG_TEXT
     NSLog(@"Sending string %s", data);
 #endif
     

README.md

 
 You can also select one of the displays connected to the Host machine. The CaseLights App will then create a Screenshot of this display 10-times per second and calculate the average color to display it on the RGB LEDs.
 
+CaseLights is also able to visualize sound coming from a system audio input. To be able to directly visualize the system sound output, install [Soundflower](https://github.com/mattingalls/Soundflower) and create a Multi-Output-Device in the Mac `Audio Midi Setup.app` consisting of `Soundflower (2ch)` and your normally used output device. Set this device as audio output. Then, in CaseLights, select `Soundflower (2ch)` as input.
+
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