Linux Shell Scripting Cookbook - Third Edition

How to do it...

Cameras commonly take a larger image than will fit on a video. You can create a motion-picture pan using the convert application to extract sections of a large image, and stitch them together into a video file with mencoder:

$> makePan.sh
# Invoke as: 
# sh makePan.sh OriginalImage.jpg prefix width height xoffset yoffset
# Clean out any old data
rm -f tmpFiles
# Create 200 still images, stepping through the original xoffset and yoffset
# pixels at a time
for o in `seq 1 200`
 do
 x=$[ $o+$5 ]
 convert -extract $3x$4+$x+$6 $1 $2_$x.jpg
 echo $2_$x.jpg >> tmpFiles
done
#Stitch together the image files into a mpg video file
mencoder mf://@tmpFiles -mf fps=30 -ovc lavc -lavcopts \  
        vcodec=msmpeg4v2 -noskip -o $2.mpg