Multiple undefined references using FFMPEG libs

Multiple undefined references using FFMPEG libs

I installed FFMPEG libraries and headers as it is described here .
In my C++ application when I compile (gcc) I am getting this :
/usr/local/lib/libavcodec.a(libfaac.o): In function Faac_encode_frame': /root/ffmpeg/libavcodec/libfaac.c:179: undefined reference tofaacEncEncode' /usr/local/lib/libavcodec.a(libfaac.o): In function Faac_encode_close': /root/ffmpeg/libavcodec/libfaac.c:52: undefined reference tofaacEncClose' /usr/local/lib/libavcodec.a(libfaac.o): In function Faac_encode_init': /root/ffmpeg/libavcodec/libfaac.c:78: undefined reference tofaacEncOpen' /root/ffmpeg/libavcodec/libfaac.c:88: undefined reference to faacEncGetCurrentConfiguration' /root/ffmpeg/libavcodec/libfaac.c:139: undefined reference to faacEncGetDecoderSpecificInfo' /root/ffmpeg/libavcodec/libfaac.c:153: undefined reference to faacEncSetConfiguration' /usr/local/lib/libavcodec.a(libfdk-aacenc.o): In function aac_encode_close': /root/ffmpeg/libavcodec/libfdk-aacenc.c:99: undefined reference to aacEncClose' /usr/local/lib/libavcodec.a(libfdk-aacenc.o): In function aac_encode_frame': /root/ffmpeg/libavcodec/libfdk-aacenc.c:344: undefined reference to aacEncEncode' /usr/local/lib/libavcodec.a(libfdk-aacenc.o): In function aac_encode_init': /root/ffmpeg/libavcodec/libfdk-aacenc.c:116: undefined reference to aacEncOpen' /root/ffmpeg/libavcodec/libfdk-aacenc.c:125: undefined reference to aacEncoder_SetParam' /root/ffmpeg/libavcodec/libfdk-aacenc.c:132: undefined reference to aacEncoder_SetParam' /root/ffmpeg/libavcodec/libfdk-aacenc.c:140: undefined reference to aacEncoder_SetParam' /root/ffmpeg/libavcodec/libfdk-aacenc.c:160: undefined reference to aacEncoder_SetParam' /root/ffmpeg/libavcodec/libfdk-aacenc.c:167: undefined reference to aacEncoder_SetParam' /usr/local/lib/libavcodec.a(libfdk-aacenc.o):/root/ffmpeg/libavcodec/libfdk-aacenc.c:185: more undefined references to aacEncoder_SetParam' follow /usr/local/lib/libavcodec.a(libfdk-aacenc.o): In function aac_encode_init': /root/ffmpeg/libavcodec/libfdk-aacenc.c:263: undefined reference to aacEncEncode' /root/ffmpeg/libavcodec/libfdk-aacenc.c:269: undefined reference to aacEncInfo' /usr/local/lib/libavcodec.a(libmp3lame.o): In function mp3lame_encode_frame': /root/ffmpeg/libavcodec/libmp3lame.c:204: undefined reference tolame_encode_buffer_float' /root/ffmpeg/libavcodec/libmp3lame.c:188: undefined reference to lame_encode_buffer' /root/ffmpeg/libavcodec/libmp3lame.c:191: undefined reference tolame_encode_buffer_int' /root/ffmpeg/libavcodec/libmp3lame.c:210: undefined reference to lame_encode_flush' /usr/local/lib/libavcodec.a(libmp3lame.o): In functionmp3lame_encode_close': /root/ffmpeg/libavcodec/libmp3lame.c:88: undefined reference to lame_close' /usr/local/lib/libavcodec.a(libmp3lame.o): In function mp3lame_encode_init': /root/ffmpeg/libavcodec/libmp3lame.c:100: undefined reference to lame_init' /root/ffmpeg/libavcodec/libmp3lame.c:104: undefined reference to lame_set_num_channels' /root/ffmpeg/libavcodec/libmp3lame.c:105: undefined reference to lame_set_mode' /root/ffmpeg/libavcodec/libmp3lame.c:108: undefined reference to lame_set_in_samplerate' /root/ffmpeg/libavcodec/libmp3lame.c:109: undefined reference to lame_set_out_samplerate' /root/ffmpeg/libavcodec/libmp3lame.c:113: undefined referenc