@Pe3s
If I get You right, you're asking, if it is possible to write a VideoPlayer, that runs inside a LCL-Form.
Yes, it is with a little Help of a
VideoPlayback-Library, or (better

) with my FFmpeg-based Audio/Video-RenderingEngine 'FFPlay4Laz':
The latest Version with SDL2 is
here, the latest Version with FFPlay4Laz-Library and Demo-LCL-GUI (but still SDL1) is
here.