Update for changed lavf API.

The buffer now needs to have been allocated with av_malloc.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36397 b3059339-0415-0410-9bf9-f77b7e298cf2
Add define to silence FFmpeg warnings.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36398 b3059339-0415-0410-9bf9-f77b7e298cf2
Add support for rtsp:// falling back to support via FFmpeg.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36399 b3059339-0415-0410-9bf9-f77b7e298cf2