Fixed crash with ffmpeg 1.1.

git-svn-id: https://www.libavg.de/svn/trunk/libavg@8917 44470bb9-56e9-0310-a0f8-c586564d3dc6
Cosmetics.

git-svn-id: https://www.libavg.de/svn/trunk/libavg@8918 44470bb9-56e9-0310-a0f8-c586564d3dc6