Videos can be overlaid with text; TV programs often do this to show the name of the speaker or give some context information. This text element is called lower third ("Bauchbinde" or "Insert" in German).
In Kdenlive, you can achieve this by adding a title on a video layer above the video and combining them with a Composite transition. It makes the title appear instantly, and removes it again instantly when the title ends.
To make the text actually fade in, you have to use an Affine transformation and animate the opacity with some keyframes.
- Add the video clip to the second video track
- Create a title clip with the text you want to show and add it to the first video track. The transition type is automatically set to "Affine".
- In the affine transition properties, add keyframes at 0, 1, 4 and 5 seconds (for a title clip with a length of 5 seconds).
- Set the opacity at 0 and 5 seconds to 0, keep it at 100 for seconds 1 and 4.
- Play it. The title text will fade in for 1 second, stay for 3 seconds and fade out for 1 second.