Media Overlays is power feature to add short video/audio content over main content.

How to

Media Overlays placed on “Overlays” dialog near with lower third and other.

You can use for overlays:

• Video file (mp4, mov)
• Audio file (mp3, wav, m4a)
• Static image (png, jpeg)
• Animated image (gif)

Example

Intro/Middle/Post roll

Countdown clip

You can apply overlay effect

Audio control in place

Source for footage

You can found many footage (countdowns, etc) in video stocks and YouTube, Vimeo. You can use video with black background.

For example:

We download this clip from YouTube

and add it as Media Overlay and apply effect: