Unity3d动态加载本地音乐，UnityWebRequestMultimedia不卡顿

private AudioSource aud;    
private void Awake()
    {
         aud = GetComponent<AudioSource>();
    }
//filepath 绝对路径 安卓sdcard 或者PC 绝对路径
public IEnumerator LoadMusic(string filepath)
    {
        filepath = "file://" + filepath;
        using (var uwr = UnityWebRequestMultimedia.GetAudioClip(filepath, AudioType.UNKNOWN))
        {
//不卡顿的2行代码
            ((DownloadHandlerAudioClip)uwr.downloadHandler).compressed = false;
            ((DownloadHandlerAudioClip)uwr.downloadHandler).streamAudio = true;
            yield return uwr.SendWebRequest();
            if (uwr.isNetworkError)
            {
                Debug.LogError(uwr.error);
            }
            else
            {
                AudioClip clip = DownloadHandlerAudioClip.GetContent(uwr);
                if (aud.clip!=null) //释放上次的
                {
                    AudioClip.Destroy(aud.clip);
                }
                aud.clip = clip;
                aud.Play();//播放
            }
        }
    }