gospec/main.go

package main

import (

)
import (
	"os"
	"fmt"
	"github.com/mjibson/go-dsp/wav"
	"github.com/mjibson/go-dsp/dsputils"
	"github.com/mjibson/go-dsp/fft"
	"github.com/mjibson/go-dsp/window"
	"math"
)

var spec_framerate = 144
var fft_length int = 1024
var display_length = 32
var freq_varying_offset float64 = float64(fft_length) * 0.000005

func main() {
	//fmt.Println(fft.FFTReal([]float64 {1, 2, 3}))

	r, err := os.Open("./file.wav")
	if err != nil {
		fmt.Println("File open error: ", err)
		return
	}
	wr, err := wav.New(r)
	if err != nil {
		fmt.Println("Wav read error: ", err)
		return
	}
	fmt.Printf("WAV:%+v\n", wr)
	//fmt.Println("Frame size: ", frame_size)
	var floats []float32
	for i := 0; i < 4000; i++ {
		floats, err = wr.ReadFloats(fft_length * int(wr.NumChannels))
	}

	if err != nil {
		fmt.Println("Error reading samples: ", err)
	}

	//fmt.Println("Floats!: ", floats)
	upgraded := averageChannels(floats, int(wr.NumChannels))


	window.Apply(upgraded, window.Hann)

	c := dsputils.ToComplex(upgraded)

	ifs := fft.IFFT(c)
	//fmt.Println("IFFT: ", ifs[1:])
	mag := make([]float64, display_length)
	var total float64 = 0.0
	counter := 0
	for _, n := range ifs[1:display_length + 1] {
		mag[counter] = math.Sqrt(real(n)*real(n) + imag(n)*imag(n))
		fmt.Printf("\nMag:%+v\n", mag[counter])
		total += mag[counter]
		counter++
	}
	for i, n := range mag {
		z := int(math.Floor((n / freq_varying_offset - 0.02) * 10))
		fmt.Printf("\n%dHz:\t\t|", wr.SampleRate/uint32(fft_length)*uint32(i))
		for i := 0; i < z; i++ {
			fmt.Print("X")
		}
	}
	fmt.Println("\nTotal: ", total)

}

func averageChannels(input []float32, channels int) []float64 {
	//the length of input should always be a multiple of channels

	counter := 0
	output := make([]float64, len(input)/channels)

	for i := 0; i < len(input); i+= channels {
		var average float64 = 0.0
		for _, n := range input[i:i+channels] {
			average += float64(n)
		}
		output[counter] = average/float64(channels)
		counter++
	}
	//fmt.Printf("Ouput:%+v\n%d", output, len(output))
	//fmt.Printf("Length of input:%d\nLength of output:%d\nChannels:%d", len(input), len(output), channels)

	return output
}