#!/bin/bash
from="gphotos-sync"
size="400"
to="gphotos-sync-$size"
mkdir -p "$to"
run() {
	v magick convert "$from/$1" -resize 400x400^ "$to/$1"
}

(
	cd "$from"
	find . -type d
) | (
	cd "$to"
	xa mkdir -pv
)
(
	cd "$from"
	find . -type f
) |
while read F; do
	run "$F" &
	for I in `seq 1 12`; do
		read F || break
		run "$F" &
	done
	wait
done