Usage
FFmpegSource(string source, int track = -1, bool forceseek = false)
source: source file
track: video track nubmer as seen by the relevant demuxer, must be a video track
       negative values means the first found video track
forceseek: seek even if the format has no registered index, only useful for containers with limited avformat support

Compatibility
AVI, MKV, MP4: Frame accurate
OGM: Messed up first frame and seeking produces smearing with forceseek=true, incredibly slow seeking without
WMV: No seeking
VOB: No rff flags, otherwise it appears to work
TS: Seeking goes way off, number of total frames is probably off too

Compiling
zlib compiled DLL from http://www.zlib.net/

ffmpeg svn from http://ffmpeg.mplayerhq.hu/

required configuration
./configure --enable-shared --disable-static --enable-memalign-hack --enable-swscaler --enable-gpl

suggested additions
--disable-encoders --disable-muxers