If image.jpg has a resolution of 720x576 you can use the following command chain to create image.mpg:
What tools are available to resize JPG images??
Thanks
cat image.jpg \ | jpegtopnm \ | ppmtoppm \ | ppmtoy4m -F 25:1 -A 4:3 -I p -r -S 420_mpeg2 -v 2 -n 1 \ | mpeg2enc -f 8 -a 2 -q 1 -n p -T 120 -R 2 -g 12 -G 12 -o image.mpg