I have doubt in how to upload a video and audio files and display them in the UI screen like we see in the Youtube. If the user click on play button the video or audio should be played.
Select the file to be uploaded to the server (No matter what type it is)
For this the vaadin Upload component can be used.
The file is then on your server and can/should be stored on the server disk
(Optional) transcode the file in a format supported by your media player used in step 3
This has nothing to do with vaadin and is usually very cpu intensive
Embed a media player in vaadin to playback the encoded file