>source

$ sudo apt-get install ffmpeg
$ sudo pacman -S ffmpeg

$ ffmpeg -i InputFile -f OutputFormatFile -b OutputVideoRate -ar SoundFreq -ab AudioBitrate -s VideoOutputDimension name-file.OutputFormatFile

example

$ ffmpeg -i xxx.avi -f flv -b 768 -ar 22500  -ab 96 -s 700×400 xxx1.flv