private void SetupVideo(string clipName,
                                bool loop,
                                int loopBackFrame)
        {
            if (!_isInited)
            {
                Init();
            }

            // video player
            var clip = Resources.Load <VideoClip>(RESOURCES_PATH + clipName);

            if (clip == null)
            {
                Debug.LogError("Not Found VideoClip : path = " + RESOURCES_PATH + clipName);
                return;
            }

            _vp.clip        = clip;
            _vp.playOnAwake = false;
            _vp.isLooping   = loop;
            _loopBackFrame  = loopBackFrame;
            // raw image
            _image.DOComplete();
            _image.SetAlpha(0);
        }