Video resize / compression
ffmpeg -i input.avi -s 720x480 -c:a copy output.mkv
ffmpeg -i input.avi -filter:v scale=720:-1 -c:a copy output.mkvVideo Speedup https://trac.ffmpeg.org/wiki/How%20to%20speed%20up%20/%20slow%20down%20a%20video
ffmpeg -i input.mkv -filter:v "minterpolate='mi_mode=mci:mc_mode=aobmc:vsbmc=1:fps=120'" output.mkvMake Preview:
Adjust $N and $F by dividing N/F to approximate the length of the video
Source: https://trac.ffmpeg.org/wiki/Create%20a%20thumbnail%20image%20every%20X%20seconds%20of%20the%20video#thumbnailvideofilter
Pick one of the most representative frames in sequences of $N consecutive frames:
ffmpeg -i input.flv -vf thumbnail=n=$N thumb%04d.png
Source: https://trac.ffmpeg.org/wiki/Slideshow#Sequential
Make Slideshow
ffmpeg -framerate $F -i img%03d.png output.mp4Copy audio stream without re-encoding Source: https://stackoverflow.com/a/27413824
ffmpeg -i input-video.avi -vn -acodec copy output-audio.aacExtract audio with re-encoding Source:
ffmpeg -i sample.avi -q:a 0 -map a sample.mp3