package services

import (
	"github.com/tosone/minimp3"
)

// GetMP3PlayDuration 获取MP3的时长
func GetMP3PlayDuration(mp3Data []byte) (seconds int, err error) {
	dec, _, err := minimp3.DecodeFull(mp3Data)
	if err != nil {
		return 0, err
	}
	if dec.Kbps <= 0 {
		return 0, err
	}
	// 音乐时长 = (文件大小(byte) - 128(ID3信息)) * 8(to bit) / (码率(kbps b:bit) * 1000)(kilo bit to bit)
	seconds = (len(mp3Data) - 128) * 8 / (dec.Kbps * 1000)
	return seconds, nil
}