指定完路径后又会出现这个报错:
/usr/bin/ld: /tmp/cckot2Gv.o: undefined reference to symbol 'avcodec_open2@@LIBAVCODEC_FFMPEG_56'
//usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status