Playing the video doesn't work anymore

When I use the MP4 file format for playback, only the sound has no picture. Is it wrong for me?

var video = Content.Load<Video> ("testVideo");
var videoPlayer = new VideoPlayer();
videoPlayer.Play(video);

videoPlayer.GetTexture() When I use this method, I return a null value, I don’t know how to solve this problem.

What version of MonoGame does the bug occur on:

MonoGame 3.7

What operating system are you using:

Windows

What MonoGame platform are you using:

WindowsDX

Is your MP4 encoded in a supported format?

I use the player is normal, but it can not be presented in monogame. I don’t know if anyone has encountered this situation. The GetTexture method will return a null value. When I use the WMV format, GetTexture is successfully acquired, but there is no sound.