wavegen/wavegen_test.go at master · rodrigo-dc/wavegen · GitHub

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package wavegen_test

import (
	"math"
	"testing"

	"github.com/rodrigo-dc/wavegen"
)

// C7 2093 Hz - Generated by GNU Octave 4.4.1
// fs = 44100; f = 2093; t = 0:1/fs:(1/f); x = sin(2*pi*f*t)
// Last value discarded.
var c7At44100 = []float64{
	0.00000, 0.29380, 0.56167, 0.77996, 0.92941, 0.99682, 0.97624, 0.86949,
	0.68600, 0.44195, 0.15890, -0.13819, -0.42307, -0.67061, -0.85896, -0.97149,
	-0.99827, -0.93693, -0.79290, -0.57887, -0.31376}

var squareC7At44100 = []float64{
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
}

func TestSine(t *testing.T) {
	samples, err := wavegen.Sine(2093, 44100)
	if err != nil {
		t.Error(err)
	}

	if len(samples) != len(c7At44100) {
		t.Error("wrong number of samples")
	}
	for i := range samples {
		if diff := math.Abs(samples[i] - c7At44100[i]); diff > 0.02 {
			t.Errorf("wrong sample at index %d", i)
		}
	}
}

func TestSine8Bits(t *testing.T) {
	expected := []byte{128, 255, 128, 0}
	samples, err := wavegen.Sine8Bits(1, 4)
	if err != nil {
		t.Error(err)
	}

	if len(samples) != 4 {
		t.Error("wrong number of samples")
	}

	for i := range samples {
		if samples[i] != expected[i] {
			t.Errorf("wrong sample at index %d", i)
		}
	}
}

func TestSquare(t *testing.T) {
	samples, err := wavegen.Square(2093, 44100)
	if err != nil {
		t.Error(err)
	}

	if len(samples) != len(squareC7At44100) {
		t.Error("wrong number of samples")
	}
	for i := range samples {
		if samples[i] != squareC7At44100[i] {
			t.Errorf("wrong sample at index %d", i)
		}
	}
}

func TestSqare8Bits(t *testing.T) {
	expected := []byte{255, 255, 0, 0}
	samples, err := wavegen.Square8Bits(1, 4)
	if err != nil {
		t.Error(err)
	}

	if len(samples) != 4 {
		t.Error("wrong number of samples")
	}

	for i := range samples {
		if samples[i] != expected[i] {
			t.Errorf("wrong sample at index %d", i)
		}
	}
}

func TestSineNyquist(t *testing.T) {
	_, err := wavegen.Sine(22051, 44100)
	if err == nil {
		t.Error("expected an error")
	}
}

func TestSine8BitsNyquist(t *testing.T) {
	_, err := wavegen.Sine8Bits(4, 7)
	if err == nil {
		t.Error("expected an error")
	}
}

func TestSquareNyquist(t *testing.T) {
	_, err := wavegen.Square(22051, 44100)
	if err == nil {
		t.Error("expected an error")
	}
}

func TestSquare8BitsNyquist(t *testing.T) {
	_, err := wavegen.Square8Bits(22051, 44100)
	if err == nil {
		t.Error("expected an error")
	}
}