add normalize flag

Author: noriah

cmd/catnip/config.go

@@ -38,6 +38,8 @@ type config struct {
 	drawType int
 	// Combine determines if we merge streams (stereo -> mono)
 	combine bool
+	// Don't run math.Log on the output of the analyzer
+	dontNormalize bool
 	// Use threaded processor
 	useThreaded bool
 	// Invert the order of bin drawing
@@ -67,6 +69,7 @@ func newZeroConfig() config {
 		spaceSize:                  1,
 		channelCount:               2,
 		drawType:                   int(graphic.DrawDefault),
+		dontNormalize:              false,
 		combine:                    false,
 		useThreaded:                false,
 		invertDraw:                 false,

cmd/catnip/main.go

@@ -77,10 +77,11 @@ func main() {
 		Output:   display,
 		Windower: window.Lanczos(),
 		Analyzer: dsp.NewAnalyzer(dsp.AnalyzerConfig{
-			SampleRate: cfg.sampleRate,
-			SampleSize: cfg.sampleSize,
-			SquashLow:  true,
-			BinMethod:  dsp.MaxSampleValue(),
+			SampleRate:    cfg.sampleRate,
+			SampleSize:    cfg.sampleSize,
+			SquashLow:     true,
+			DontNormalize: cfg.dontNormalize,
+			BinMethod:     dsp.MaxSampleValue(),
 		}),
 		Smoother: dsp.NewSmoother(dsp.SmootherConfig{
 			SampleSize:      cfg.sampleSize,
@@ -137,6 +138,7 @@ func doFlags(cfg *config) bool {
 	parser.Int(&cfg.barSize, "bw", "bar", "bar width [1, +Inf)")
 	parser.Int(&cfg.spaceSize, "bs", "space", "space width [0, +Inf)")
 	parser.Int(&cfg.drawType, "dt", "draw", "draw type (1, 2, 3, 4, 5, 6)")
+	parser.Bool(&cfg.dontNormalize, "dn", "dont-normalize", "dont normalize analyzer output")
 	parser.Bool(&cfg.useThreaded, "t", "threaded", "use the threaded processor")
 	parser.Bool(&cfg.invertDraw, "i", "invert", "invert the direction of bin drawing")
 

dsp/analyzer.go

@@ -15,11 +15,12 @@ import "math"
 type BinMethod func(int, float64, float64) float64
 
 type AnalyzerConfig struct {
-	SampleRate   float64   // audio sample rate
-	SampleSize   int       // number of samples per slice
-	SquashLow    bool      // squash the low end the spectrum
-	SquashLowOld bool      // squash the low end using the old method
-	BinMethod    BinMethod // method used for calculating bin value
+	SampleRate    float64   // audio sample rate
+	SampleSize    int       // number of samples per slice
+	SquashLow     bool      // squash the low end the spectrum
+	SquashLowOld  bool      // squash the low end using the old method
+	DontNormalize bool      // dont run math.Log on output
+	BinMethod     BinMethod // method used for calculating bin value
 }
 
 type Analyzer interface {
@@ -30,10 +31,11 @@ type Analyzer interface {
 
 // analyzer is an audio spectrum in a buffer
 type analyzer struct {
-	cfg      AnalyzerConfig // the analyzer config
-	bins     []bin          // bins for processing
-	binCount int            // number of bins we look at
-	fftSize  int            // number of fft bins
+	cfg           AnalyzerConfig // the analyzer config
+	bins          []bin          // bins for processing
+	binCount      int            // number of bins we look at
+	fftSize       int            // number of fft bins
+	dontNormalize bool           // dont normalize the output
 }
 
 // Bin is a helper struct for spectrum
@@ -107,9 +109,10 @@ func MinNonZeroSampleValue() BinMethod {
 
 func NewAnalyzer(cfg AnalyzerConfig) Analyzer {
 	return &analyzer{
-		cfg:     cfg,
-		bins:    make([]bin, cfg.SampleSize),
-		fftSize: cfg.SampleSize/2 + 1,
+		cfg:           cfg,
+		bins:          make([]bin, cfg.SampleSize),
+		fftSize:       cfg.SampleSize/2 + 1,
+		dontNormalize: cfg.DontNormalize,
 	}
 }
 
@@ -151,7 +154,9 @@ func (az *analyzer) ProcessBin(idx int, src []complex128) float64 {
 		return 0.0
 	}
 
-	mag = math.Log(mag)
+	if !az.dontNormalize {
+		mag = math.Log(mag)
+	}
 
 	if mag < 0.0 {
 		return 0.0