This is just some cheat sheet about the FFmpeg command line. To know about the history there is link.

This tool is very good if you are in any kind of job with video or live streaming. You can convert from any format to any other format. Even some mp4 to mp3, or different format codec.

Cut from second 10 up to next 10 seconds. So from 10 to 20 seconds of video would be new 10 seconds video.

ffmpeg -ss 00:00:10.0 -i somevideo.mp4 -c copy -t 00:00:10.0 outsomevideo.mp4

You have a video in ISO Media, MP4 v2 [ISO 14496-14] and twitter does not want to play. So you need ISO Media, MP4 Base Media v1 [IS0 14496-12:2003]

ffmpeg -i input.mp4 -c copy -map 0 -brand mp41 output.mp4

To copy the video from video.mp4 and audio from music.mp4:

ffmpeg -i video.mp4 -i music.mp4 -c copy -map 0:0 -map 1:1 -shortest output.mp4

"Burn" subtitles to video. First convert .srt to .ass

ffmpeg -i somesub.srt somesub.ass

Then add them:

ffmpeg -i ourfavmovienosub.mp4 -vf ass=somesub.ass ourfavmovieswithsub.mp4

If you want to mute or silence some part of video(let say from 0:30 to 1:30:

ffmpeg -i ourfavmovies.mp4 -vcodec copy -af "volume=enable='between(t,30,90)':volume=0" outourfavmovies.mp4

Extracting pictures from video, each second:

ffmpeg -i  favmovies.mp4 -vf fps=1 pic%04d.jpg -hide_banner

I hope this helps you with video editing.