Video Compression

ffmpeg -i "<input.mp4>" -vcodec <codec> -acodev <codec> -crf <level> "<output.mp4>"

This takes input.mp4 and turns it into output.mp4 with a certain level of compression as specified by the -crf value.

The crf or Constant Rate Factor (opens in a new tab) lowers average bitrate while retaining better quality. It can range from 18 to 24 for H.264 and 24 to 30 for H.265. A higher CRF value corresponds to a lower bitrate, hence producing a smaller file.

The following shorthand may be used as well, since ffmpeg performs some optimizations on it's own.

ffmpeg -i "<input.mp4>" "<output.mp4>"

Codecs:

# vcodes
h264
h265
 
# acodes
aac
mp3

Sources: [1] (opens in a new tab) [2] (opens in a new tab)