Does anyone know of....

[ToddFrankson 3]

A delphi component that can play videos from a Stream???

[Anders Melander 1861]

There's the old TMediaPlayer but AFAIR it's a pain (but possible) to get to work with TStream.

 

A better alternative would be to import the type library for the Windows Media Player ActiveX and use that.
https://chapmanworld.com/windows-media-player-in-delphi/

[Der schöne Günther 323]

Maybe just a TWebBrowser (preferably using the Edge/WebView2 engine) is an option?