[Libav-user] undefined reference errors from linker

Carl Eugen Hoyos cehoyos at ag.or.at
Wed Jan 23 10:52:00 CET 2013

Srinath M <srinath3142 at ...> writes:

> clang -o tld tld.o -L"../lib" -lccv -lavformat -lavcodec -lswscale -lz -lm
> /usr/local/lib/libavformat.a(concat.o): In function `concat_close':
> /home/srinath/Downloads/ffmpeg-1.1.1/libavformat/concat.c:52: 
> undefined reference to `av_freep'

Whenever you link with one of FFmpeg's libraries, you 
have to add avutil which is a prerequisite for all 
other libraries.

Generally, it may be a good idea to run "grep" in such 
a case (or even nm), it may tell you were the missing 
symbol is defined.

Please do not top-post here, it is considered rude.

Carl Eugen

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