Video encodes 25 frames instead of 30.(please specify the path to the settings)

Hello!How can I change the video processing settings from 25 frames to 30 frames?All modern smartphones and cameras shoot video at 30 frames per second,and your social network processes video at 25 frames,which leads to Gating!Video after processing is jump.Please tell me what script is responsible for video processing and where it can be found?
I want to see 30 frames after encoding!