用cmake构建ffmpeg时，发现一些错误：
libavfilter/avf_showcqt.c:147: error: undefined reference to 'av_fft_end'
libavfilter/avf_showcqt.c:718: error: undefined reference to 'avpriv_vga16_font'
libavfilter/avf_showcqt.c:1383: error: undefined reference to 'av_fft_init'
libavfilter/avf_showcqt.c:1151: error: undefined reference to 'av_fft_permute'
libavfilter/avf_showcqt.c:1152: error: undefined reference to 'av_fft_calc'
libavfilter/avf_showfreqs.c:183: error: undefined reference to 'av_audio_fifo_free'
libavfilter/avf_showfreqs.c:184: error: undefined reference to 'av_fft_end'
libavfilter/avf_showfreqs.c:185: error: undefined reference to 'av_fft_init'
这是我的链接配置：
lib_avformat
lib_avcodec
lib_swscale
lib_avutil
lib_avfilter
lib_swresample
lib_postproc
lib_avdevice
lib_mp3lame
lib_fdk-aac
lib_x264