Editing Zoom recordings of teaching sessions with FFmpeg

What is the easiest way to edit Zoom recordings of lectures? This time I tried FFmpeg.

Before putting recorded Zoom lectures for internal distribution to OneDrive, I try to do minimal post-processing, namely cutting out "slack" (e.g. breaks). I know that all 12-year-olds on TikTok can do this on their smartphones, but being a dinosaur I have done it on the command line using FFmpeg.

From yesterday's session, I wanted to cut out slack space from the beginning and the end and a 15 minutes break in between. In addition, we had played a song, which quality-wise did not work well via Zoom. Zoom works great for talking heads, but it sucks at streaming music. Hence, I separately downloaded the song Viva La Evidence using youtube-dl, which had become recently famous due to the IRA take-down request to GitHub. I "knocked-in" this song to improve the audio quality.

See the original blog post with all the commands for details!