Use the following command ffmpeg -vframes 200 -f image2 -i airport1%03d.bmp -f avi -vcodec rawvideo -pix_fmt bgr24 -acodec pcm_s16le airport.avi This will convert all the files airport1000.bmp to airport1200.bmp to an avi file. Using mencoder will allow you to chose the framerate: mencoder “mf://*.bmp” -mf fps=12 -o out.avi -ovc lavc -lavcopts vcodec=msmpeg4v2:vbitrate=800