1. Delay output mode has three preview windows: PGM, DLY1, DLY2.

2. PGM

       Preview the video after switching.

3. DLY1

       Preview delayed video.

4. DLY2

       Preview the final output video.

If no padding video is played, DLY1 and DLY2 are exactly the same.

After switching the padding video, DLY2 will display the padding video, that is, skip the delay video and play the padding video.