Remember to check if you need to bump versions for the specific libav
    parts (libavutil, libavcodec, libavformat) you are changing. You need
    to change the version integer and the version string.
    Incrementing the first component means no backward compatibility to
    previous versions (e.g. removal of a function).
    Incrementing the second component means backward compatible change
    (e.g. addition of a function).
    Incrementing the third component means a noteworthy binary compatible
    change (e.g. encoder bug fix that matters for the decoder).