[Libav-user] ffmpeg static library linking issue

[Alex Cohn]

On Tue, Feb 7, 2012 at 12:43, yuvaraj r <yuvaraj.tr at gmail.com> wrote:
> I have only static libraries
>
> Thanks
>
> Yuvaraj

I'd recommend to add -Wl,--no-undefined to your gcc command line.

Alex

> On Tue, Feb 7, 2012 at 4:10 PM, Alex Cohn <alexcohn at netvision.net.il> wrote:
>> 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