implement video downsizing function for client side

[sparklingwter]

Description:
Downsizing is not the same as compression. In the codebase, frameskip is implemented, meaning that some data points are lost. We want to be able to process the entire video without taking forever to upload and produce analysis result.

The solution is to downsize the video (eg: 4K to 720). The ideal resolution suggested by Taz is 720p. This allows us to process the entire videos with a relatively high resolution

Resources:
https://www.ffmpeg.org/