This article lists out some common commands for FFMPEG.

echo -n “secretsecretIgottasecret” | openssl enc -base64 -e -aes-256-cbc -nosalt

:gpg –print-md sha1 test.txt
test.txt: 2D20 A03A B0F5 C835 2DA4 3DDA 7C60 CA0F 1D69 A55B

mkvmerge -o output.mkv input1.mkv +input2.mkv
mkvmerge -o output.mkv combined.mkv –split parts:00:00:00-00:43:00

dd if=/dev/cdrom of=image_name.iso