错误：
/usr/bin/ld: /usr/local/lib/libavcodec.a(vc1dsp_mmx.o): relocation R_X86_64_PC32 against symbol `ff_pw_9' can not be used when making a shared object; recompile with -fPIC /usr/bin/ld: final link failed: Bad value collect2: error: ld returned 1 exit status
网上所有教程，都说加-fPIC。大多情况下有用，个别情况下没用。比如编译FFmpeg。这个时候，你需要如下操作：
export ECFLAG="-fPIC" ./configure \ --extra-cflags="-fPIC " \
