feat: gemini audio input billing

service/audio.go

@@ -3,6 +3,7 @@ package service
 import (
 	"encoding/base64"
 	"fmt"
+	"strings"
 )
 
 func parseAudio(audioBase64 string, format string) (duration float64, err error) {
@@ -29,3 +30,19 @@ func parseAudio(audioBase64 string, format string) (duration float64, err error)
 	duration = float64(samplesCount) / float64(sampleRate)
 	return duration, nil
 }
+
+func DecodeBase64AudioData(audioBase64 string) (string, error) {
+	// 检查并移除 data:audio/xxx;base64, 前缀
+	idx := strings.Index(audioBase64, ",")
+	if idx != -1 {
+		audioBase64 = audioBase64[idx+1:]
+	}
+
+	// 解码 Base64 数据
+	_, err := base64.StdEncoding.DecodeString(audioBase64)
+	if err != nil {
+		return "", fmt.Errorf("base64 decode error: %v", err)
+	}
+
+	return audioBase64, nil
+}