Impress video file incompatibility

Windows 10. LibraOffice 7.0.4.2

In order to insert a video clip I have to convert my MP4 file which seems strange as it is such a common format.
OGG is recommended but that didn’t work either. AVI is ok but why all this hassle.
Which file converter would you recommend?

Most likely it is MP4 is patent encumbered. Since it isnt free spec the support isnt there. Using open and free data formats keeps The ODF from getting sued by the sue happy for infringment.