mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-12-27 04:08:53 +01:00
90 lines
2.2 KiB
Go
90 lines
2.2 KiB
Go
// Copyright 2018 The Ebiten Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package convert_test
|
|
|
|
import (
|
|
"io/ioutil"
|
|
"math"
|
|
"testing"
|
|
|
|
"github.com/hajimehoshi/ebiten/audio"
|
|
. "github.com/hajimehoshi/ebiten/audio/internal/convert"
|
|
)
|
|
|
|
func soundAt(timeInSecond float64) float64 {
|
|
const freq = 220
|
|
|
|
amp := []float64{1.0, 0.8, 0.6, 0.4, 0.2}
|
|
v := 0.0
|
|
for j := 0; j < len(amp); j++ {
|
|
v += amp[j] * math.Sin(2.0*math.Pi*timeInSecond*freq*float64(j+1))
|
|
}
|
|
if v > 1 {
|
|
v = 1
|
|
}
|
|
if v < -1 {
|
|
v = -1
|
|
}
|
|
return v
|
|
}
|
|
|
|
func newSoundBytes(sampleRate int) []byte {
|
|
b := make([]byte, sampleRate*4) // 1 second
|
|
for i := 0; i < len(b)/4; i++ {
|
|
v := soundAt(float64(i) / float64(sampleRate))
|
|
v16 := int16(v * (1<<15 - 1))
|
|
b[4*i] = byte(v16)
|
|
b[4*i+1] = byte(v16 >> 8)
|
|
b[4*i+2] = byte(v16)
|
|
b[4*i+3] = byte(v16 >> 8)
|
|
}
|
|
return b
|
|
}
|
|
|
|
func TestResampling(t *testing.T) {
|
|
cases := []struct {
|
|
In int
|
|
Out int
|
|
}{
|
|
{
|
|
In: 44100,
|
|
Out: 48000,
|
|
},
|
|
{
|
|
In: 48000,
|
|
Out: 44100,
|
|
},
|
|
}
|
|
for _, c := range cases {
|
|
inB := newSoundBytes(c.In)
|
|
outS := NewResampling(audio.BytesReadSeekCloser(inB), int64(len(inB)), c.In, c.Out)
|
|
gotB, err := ioutil.ReadAll(outS)
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
wantB := newSoundBytes(c.Out)
|
|
if len(gotB) != len(wantB) {
|
|
t.Errorf("len(gotB) == %d but len(wantB) == %d", len(gotB), len(wantB))
|
|
}
|
|
for i := 0; i < len(gotB)/2; i++ {
|
|
got := float64(int16(gotB[2*i])|(int16(gotB[2*i+1])<<8)) / (1<<15 - 1)
|
|
want := float64(int16(wantB[2*i])|(int16(wantB[2*i+1])<<8)) / (1<<15 - 1)
|
|
if math.Abs(got-want) > 0.025 {
|
|
t.Errorf("sample rate: %d, index: %d: got: %f, want: %f", c.Out, i, got, want)
|
|
}
|
|
}
|
|
}
|
|
}
|