vid.stab is free software under the GNU Lesser General Public License,
version 2.1 or (at your option) any later version.  The full text is in
COPYING.LESSER.

An application may link vid.stab without taking on this licence.  What the
LGPL asks in return is that the library itself stays free: if you distribute
a modified vid.stab, you publish the modifications under the LGPL too.

Every source file carries an SPDX-License-Identifier line.

Releases up to and including v1.1.2 were under the GPL.  The library was
relicensed afterwards, with the agreement of its copyright holders; see
RELICENSE.md.
