How to save 3 FEA animations side by side into one video clip?

I have shown the three results of vibration analyses side by side simultaneously in animation. They are 1-sigma VM stress profiles. How to save these three animations in one {movie, video clip, gif, etc.}?

Save As Backup can only save one animation each time.

Other than using cellphone camera, has there a new technique developed to record the movements in the whole entire screen without discrimination?

Thanks.