Make slideshow from videos from Google Photos Album

make_slideshow.sh

#!/usr/bin/bash

# The goal of this script is to take a series of videos 
# from an album export from Google Photos
# and append them all together to make one long video.

# For example, if the videos folder contained:

# ./videos
#   - a.mp4
#   - b.mp4
#   - c.mp4

# this script would produce "out.mp4", which would contain video a, then b, then c, in order.

# When you edit a file in Google Photos, it adds a "~" to the end of the filename.
# ffmpeg does not like this, so we must remove it.
for unsafe_filename in videos/*~*.mp4; do
	safe_filename="$(echo $unsafe_filename | sed -r 's/~+/_/g')"
	echo "$unsafe_filename > $safe_filename"
	mv $unsafe_filename $safe_filename
done

# taken from https://superuser.com/a/1478595
for filename in videos/*.mp4; do
	echo "file $filename" >> concat-list.txt
done

ffmpeg -f concat -i concat-list.txt merged.mp4

echo "Concatenated videos list:"
cat concat-list.txt
rm concat-list.txt