ffmpeg cross compile

mark.

./configure --disable-everything --enable-cross-compile --cross-prefix=x86_64-w64-mingw32- --arch=x86_64 --target-os=mingw32 --disable-debug --enable-static --disable-shared --enable-memalign-hack --enable-swscale --enable-avformat --disable-avfilter --enable-w32threads  --enable-runtime-cpudetect --disable-ffprobe --enable-version3 --enable-decoder=h264 --enable-decoder=mpeg4 --enable-decoder=flv --enable-protocol=file --enable-protocol=http --disable-ffmpeg --enable-zlib --enable-parser=h264 --enable-parser=mpeg4video --enable-parser=mpegvideo --enable-demuxers --disable-encoders --enable-ffmpeg