How to use ffmpeg

Most of this is from here eh.

Basic usage

ffmpeg -i source.mp4 OPTIONS output.mp4

Important options

Use h.264 encoding

-c:v libx264

Processing speed

-preset slow

Adjust volume:

-af 'volume=1.2'

Scale the resolution (use -2 if the resolution doesn't divide well):

-vf scale=-1:720

Stretch the resolution (setsar tells player not to squish later):

-vf "scale=1280:760,setsar=1"

Quality setting (27 is probably okay)

-crf 27

Start and stop times (trim video)

-ss 00:01:54 -to 00:06:53

Crop video

-vf "crop=W:H:X:Y"

Basic audio settings: 2 channel AAC at 128k

-c:a aac -b:a 128k -ac 2