I have a YouTube video which has audio that is way too soft. It's there, and audible, but quiet enough to be hard to understand. Basically, I am looking for what this question provides, only for Linux rather than Windows.
My initial research covered a YouTube video which explained what I want to do from within YouTube hinges on a button to the bottom right of the screen saying, "Try the YouTube video editor" which is not displayed now. I have not been able to find my way into the subsequently shown audio tweaking interface.
(I have the video on my machine in original MOV format. I also have intermittent access to a Mac.)