ffmpeg 库精简

./configure --enable-cross-compile --target-os=linux --cross-prefix=arm-linux- --cc=arm-linux-gcc --arch=armv6 --prefix=/usr/local/ffmpeg-arm --extra-cflags=-I/usr/local/include --extra-ldflags=-L/usr/local/lib/ --enable-shared --disable-static --disable-doc --disable-ffmpeg --disable-ffplay --disable-ffserver --disable-avdevice --enable-avcodec --disable-network --disable-swresample --disable-swscale --disable-postproc --disable-avfilter --disable-everything --enable-demuxer=mpegts --enable-protocol=file