Create animated SVG (using SMIL) from images

imgs2svgsmil

#!/bin/bash

duration=$1; shift
if [[ ! ( $duration =~ ^[0-9]+m?s$ ) ]]; then
    echo "Usage: $0 duration img.jpg [img2.jpg …] > animation.svg"
    echo "where duration is a time number like 2s or 400ms"
fi

cat <<EOF
<svg width="100%" height="100%" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><defs>
EOF

i=0
declare -a ids_a
for f in "$@"; do
    mime=$(mimetype -b "$f")
    if [[ -z $mime || ! ( $mime =~ ^image/ )  ]]; then
        echo "no image mimetype found for $f" >&2
        continue
    fi
    (( i++ ))
    ids_a+=( $i )
    cat <<EOF
<image id="i${i}" x="0" y="0" width="100%" height="100%" preserveAspectRatio="true" xlink:href="data:${mime};base64,
EOF
    base64 "$f" | tr -d '\n'
    echo '"/>'
done

ids=$(printf "#i%s; " ${ids_a[@]})

cat <<EOF
</defs><use x="0" y="0" xlink:href="#i1"><animate attributeName="xlink:href" values="${ids}" dur="1s" repeatCount="indefinite"/></use></svg>
EOF

Leaves width/height at 100% since input images can have different w/h.