giffy

Can you tell the difference between these two animated gifs? They are different. Open each in a hex editor if you don't believe me or... use this program to decode the secret message in the second one!

Compile

make giffy

Usage

Encode a message:

$ ./giffy.exe e [input-image-file] [output-filename] [message-string]

Decode a message:

$ ./giffy.exe d [input-image-file]

Example

Encode:

$ ./giffy.exe e /input/path/to/file /desired/output/my_filename 'hey Lindsay, what is new with you?'

Decode:

$ ./giffy.exe d ~/my_filename

hey Lindsay, what is new with you?

It's just like passing notes in class.

lots of thanks to this and this.