Converting Video formats using FFMPEG

MOV to FLV
ffmpeg -i video1.mov video1.flv

Mpeg to FLV
ffmpeg -i video1.mpeg video1.flv

AVI to FLV
ffmpeg -i video1.avi -s 640×480 video1.flv

flv to mpg
ffmpeg -i video1.flv -ar 22050 -b 500 -s 320x240 video1.mpg