small updates

Author: noriah

README.md

@@ -13,7 +13,7 @@ tavis
 we are working on this project all the time. its a sort of time filler for us at this point. expect lots of additions and changes at random times.
 
 ## supported audio backends
-- PortAudio (linux/macOS/*windows**)
+- PortAudio (linux/macOS/*windblows**)
 - PulseAudio (parec/FFmpeg)
 - AVFoundation (FFmpeg)
 - ALSA (FFmpeg)
@@ -27,7 +27,7 @@ we are working on this project all the time. its a sort of time filler for us at
 	- github.com/lawl/pulseaudio
 	- gonum.org/v1/gonum
 
-- c libraries (`CGO_ENABLED=1`)
+- c libraries (optional, disable with `CGO_ENABLED=0`)
 	- fftw (fftw3)
 	- portaudio (portaudio-2.0)
 
@@ -52,10 +52,10 @@ CGO_ENABLED=0 go get github.com/noriah/tavis
 # get source
 git clone https://github.com/noriah/tavis.git
 
-# move to source
+# cd to source
 cd tavis
 
-# build tavis
+# build and install tavis
 go install
 # without cgo
 CGO_ENABLED=0 go install

config.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"errors"
+
 	"github.com/noriah/tavis/dsp"
 	"github.com/noriah/tavis/graphic"
 	"github.com/noriah/tavis/input"
@@ -62,6 +64,24 @@ func NewZeroConfig() Config {
 
 func sanitizeConfig(cfg *Config) error {
 
+	if cfg.SampleRate < float64(cfg.SampleSize) {
+		return errors.New("sample rate lower than sample size")
+	}
+
+	if cfg.SampleSize < 4 {
+		return errors.New("sample size too small (4+ required)")
+	}
+
+	switch {
+
+	case cfg.ChannelCount > 2:
+		return errors.New("too many channels (2 max)")
+
+	case cfg.ChannelCount < 1:
+		return errors.New("too few channels (1 min)")
+
+	}
+
 	switch {
 	case cfg.WinVar > 1.0:
 		cfg.WinVar = 1.0

dsp/spectrum.go

@@ -163,7 +163,7 @@ func (sp *Spectrum) Process(win window.Function) {
 				mag = 0.0
 
 			case sp.bins[xB].floorFFT < bassCut:
-				pow *= math.Max(0.75, float64(xF)/fBassCut)
+				pow *= math.Max(0.5, float64(xF)/fBassCut)
 			}
 
 			mag *= sp.bins[xB].eqVal