Animations

Animation is a magical process whereby seemingly unending efforts eventually combine to make a movie.

Artists

David Revoy

Softwares

Of course we focus on Linux softwares:

Pencil2d - best as a starting point, frame by frame, both bitmaps & basic vectors.
Synfig - more technical and focused on vector animation by tweening.
Krita - for professional drawings (especially gifted artists).
OpenToonz - in between the aboves and blender.
Blender - for professional users.

There are also some proprietary software, such as Harmony

Pre-processing of the frames

The basic idea of animation is very simple, though: alternate images. If it's fast enough, the brain will interpolate a continuous evolution from one to the other. So the simplest possible animation is just to generate frames and assemble them together.

cropping

For autocropping:

for i in `ls *jpg`; do convert -trim $i out_$i; done

But if the size is not the same for all images, the encoding could fail, in this case, force the cropping:

for i in `ls *jpg`; do convert $i -crop '990x870+5+35' out_$i; mv -f out_$i $i; done

Gif

ezgif.com is a great online resource to optimize, resize, crop and overall edit gif (with some limitations on size, though).

Gif files can be animated using gifsicle [1]

gifsicle --delay=10 --loop *.gif > anim.gif

The listing is such that it normal-orders the files, which is usually what one wants to do.

To convert from a movie to an animated gif:

ffmpeg -i input.mp4 -r 15 -vf scale=512:-1 output.gif

PNG

If there are few images, convert from ImageMagick can do the trick:

convert -delay 10 -loop 0 $(ls -1 *.png | sort -V) animated.gif

For more ambitious exports, use ffmpeg: (-r 20 is the repetition rate)

ffmpeg -f image2 -r 20 -i 0%05d.png -vcodec h264 -crf 0 -y output.mp4

Movies

mpeg can be generated with a command like:

mencoder "mf://*.jpg" -mf fps=10 -ovc lavc -o ./dest.avi

with 10 frames per second.

avconv is also popular. To do lossless compression, you may try:

avconv -f image2 -r 30 -i %03d.png -vcodec qtrle -pix_fmt rgb24 -t 15 qtrle-30fps-rgb.mov

Tools

Mental Canvas: drawing in 3D.

Contents