Masking a video within indesign epub

Hi, looking for suggestions on how to mask/place a video within a shape (circle, square etc) which would auto play or click play within Indesign Epub.

Currently laying objects on top of my video's to create the illusion of the video residing within a shape, but its a real time consuming pain.

Masking is such a common option within other Adobe products even for video within After Effects and Premiere and with Indesign Epub offering the experience of video it does seem to let itself down by not having a masking option. If im off the mark on this comment, appologies, but let me know if I'm able to mask a video with Indesign Epub.