This repo has a nix package for [https://github.com/lagmoellertim/unsilence]. This software will speed up gaps in videos where nobody is speaking.

To use it, type something like:

nix run github:rvl/pkg-unsilence -- -y -t4 input_file output_file

To install the unsilence command in your user's profile, run:

nix profile install github:rvl/pkg-unsilence

You may wish to use this program in conjunction with youtube-dl, which can fetch video files from many sources (e.g. YouTube, Google Drive, Udemy).

If watching the video requires logging in, then you can instruct youtube-dl to use the session cookies from your web browser.

Use the Get cookies.txt Chrome extension or cookies.txt Firefox add-on to export your browser's cookies.

Like this for example:

nix run nixpkgs#youtube-dl -- --cookies ~/Downloads/google.com_cookies.txt \
    'https://drive.google.com/file/d/MDZlohs1znRq3W1adha5ru0_izVXoaMhe/view'