ソースを参照
update ffmpeg build; other 64bit updates (from dev6 https://trac.osgeo.org/grass/changeset/37827)
git-svn-id: https://svn.osgeo.org/grass/grass/trunk@37829 15284696-431f-4ddb-bdfa-cd5b030d7da7
William Kyngesburye