Not very actively maintained these days but https://en.wikipedia.org/wiki/Dvdisaster https://en.wikipedia.org/wiki/Dvdisaster stores error correction codes in t

Not very actively maintained these days but https://en.wikipedia.org/wiki/Dvdisaster https://en.wikipedia.org/wiki/Dvdisaster stores error correction codes in the remaining space on an optical disk, without affecting its readability by unaware systems.