[Libav-user] ffmpeg static library linking issue

[Alex Cohn]

On Tue, Feb 7, 2012 at 06:54, yuvaraj r <yuvaraj.tr at gmail.com> wrote:
> Hi All,
>
>
> I compiled the ffmpeg source to generate the static(.a foramt)
> libraries  in linux.
>
> When i am linking the static libraries with my application,
>
> i am getting undefined reference for many functions.
>
> Even i tried with pkg-config.
>
> Here command , what i tried
>
>
> gcc -shared -Wl,-soname,librecorder.so.1 '-Wl,-rpath,lib'  -lpthread
> -lXdamage -lXfixes -lXmu -lXi -lX11
> -L/home/peter/Desktop/screenrecorder/librecorder/src/../dependencies/lib
>  -lavformat -lavcodec -lavutil -lswscale `pkg-config --libs --cflags
> libavutil` `pkg-config --libs --cflags libswscale` `pkg-config --libs
> --cflags libavcodec` `pkg-config --libs --cflags libavformat` -o
> librecorder.so.1.1 init.o main_entry.o xtoffmpeg.o
>
>
> It is generated the librecorder library. I have all dependency libs
>
> when executing ld command
>
> #ld librecorder.so.1.1
>
> librecorder.so.1: undefined reference to `av_new_stream'
> librecorder.so.1: undefined reference to `av_read_packet'
> librecorder.so.1: undefined reference to `avcodec_alloc_frame'
> librecorder.so.1: undefined reference to `av_close_input_file'
> librecorder.so.1: undefined reference to `audio_resample'
> librecorder.so.1: undefined reference to `avcodec_find_encoder'
> librecorder.so.1: undefined reference to `av_find_input_format'
> librecorder.so.1: undefined reference to `avcodec_encode_audio'
> librecorder.so.1: undefined reference to `dump_format'
> librecorder.so.1: undefined reference to `av_open_input_file'
> librecorder.so.1: undefined reference to `avcodec_find_decoder'
> librecorder.so.1: undefined reference to `avcodec_close'
> librecorder.so.1: undefined reference to `av_find_stream_info'
> librecorder.so.1: undefined reference to `audio_resample_init'
> librecorder.so.1: undefined reference to `avpicture_get_size'
> librecorder.so.1: undefined reference to `av_register_all'
> librecorder.so.1: undefined reference to `avcodec_decode_audio'
> librecorder.so.1: undefined reference to `avcodec_open'
> librecorder.so.1: undefined reference to `avcodec_encode_video'
> librecorder.so.1: undefined reference to `av_destruct_packet_nofree'
> librecorder.so.1: undefined reference to `avpicture_fill'
> librecorder.so.1: undefined reference to `av_set_parameters'
> librecorder.so.1: undefined reference to `av_alloc_format_c
>
> Now problem with static libraries.
>
>
> #pkg-config --list-all | grep mpeg
> libswscale                       libswscale - FFmpeg image rescaling library
> libavutil                        libavutil - FFmpeg utility library
> libavformat                      libavformat - FFmpeg container format library
> libavcodec                       libavcodec - FFmpeg codec library
>
>
> How do i solve this issue
>
>
> Thanks
>
>
> Yuvaraj R

As far as I know, -l flag on the gcc command line will prefer the
shared version of the library. I.e. if you have both libavformat.a and
libavformat.so visible to gcc, the latter will be used.

BR,
Alex