优化cut

api_test.go

@@ -17,7 +17,7 @@ func TestAPI(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = SaveOggToWav(u, "test.wav")
+	err = SaveOggToFile(u, "test.wav")
 	if err != nil {
 		t.Fatal(err)
 	}

ogg.go

@@ -1,6 +1,7 @@
 package ahsai
 
 import (
+	"io"
 	"net/http"
 	"os"
 	"time"
@@ -11,7 +12,25 @@ import (
 	"github.com/faiface/beep/wav"
 )
 
-func SaveOggToWav(u, path string) error {
+func cutstream(s beep.StreamSeekCloser) {
+	tmp := make([][2]float64, 1024)
+	c := 0
+	for c < 6 {
+		_, _ = s.Stream(tmp)
+		sum := (tmp[0][0] + tmp[0][1]) / 2
+		for j := 1; j < 1024; j++ {
+			sum += (tmp[j][0] + tmp[j][1]) / 2
+			sum /= 2
+		}
+		if sum < 1e-32 && sum > -1e-32 {
+			c++
+		} else {
+			c = 0
+		}
+	}
+}
+
+func SaveOggToFile(u, path string) error {
 	resp, err := http.Get(u)
 	if err != nil {
 		return err
@@ -27,17 +46,22 @@ func SaveOggToWav(u, path string) error {
 		return err
 	}
 	defer f.Close()
-	tmp := make([][2]float64, 1024)
-	_, _ = s.Stream(tmp)
-	sum := (tmp[0][0] + tmp[0][1]) / 2
-	for sum > 1e-32 || sum < -1e-32 {
-		_, _ = s.Stream(tmp)
-		sum = (tmp[0][0] + tmp[0][1]) / 2
-		for j := 1; j < 1024; j++ {
-			sum += (tmp[j][0] + tmp[j][1]) / 2
-			sum /= 2
-		}
+	cutstream(s)
+	return wav.Encode(f, s, format)
+}
+
+func SaveOggToWriteSeeker(u string, f io.WriteSeeker) error {
+	resp, err := http.Get(u)
+	if err != nil {
+		return err
 	}
+	s, format, err := vorbis.Decode(resp.Body)
+	if err != nil {
+		resp.Body.Close()
+		return err
+	}
+	defer s.Close()
+	cutstream(s)
 	return wav.Encode(f, s, format)
 }
 
@@ -52,17 +76,7 @@ func PlayOgg(u string) error {
 		return err
 	}
 	defer s.Close()
-	tmp := make([][2]float64, 1024)
-	_, _ = s.Stream(tmp)
-	sum := (tmp[0][0] + tmp[0][1]) / 2
-	for sum > 1e-32 || sum < -1e-32 {
-		_, _ = s.Stream(tmp)
-		sum = (tmp[0][0] + tmp[0][1]) / 2
-		for j := 1; j < 1024; j++ {
-			sum += (tmp[j][0] + tmp[j][1]) / 2
-			sum /= 2
-		}
-	}
+	cutstream(s)
 	err = speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/32))
 	if err != nil {
 		return err