Right-click the volume control icon on the bottom taskbar and click on "Playback Devices" to open the pop-up window for sound options. In the "Playback" tab, select "Digital Output Device" or "HDMI" as the default device, click "Set Default" and click "OK" to save the changes. This method works with a straight HDMI-to-HDMI connection;
video is perfect but the solution provided by you has a flaw.
my HDMI or DIGITAL OUTPUT DEVICE is shown "NOT PLUGGED IN"