Undefined Referernce Errors FFMPEG + QT + Ubuntu 12.04.2 LTS -

i have 2 machines ubuntu 12.04.2 lts (64 mb) , other snow leopard os. in mac work ffmpeg without trouble try use ffmpeg in ubuntu , 6700 (!) errors appear:

error: undefined reference `av_freep' error: undefined reference `av_strstart' error: undefined reference `av_freep' ... 

i use qt 4.8.5 , g++ x86 64b installed ffmpeg following http://ffmpeg.org/trac/ffmpeg/wiki/ubuntucompilationguide without errors or warnings.

my test code is:

.h

qt += core gui   includepath += \     /usr/local/include  libs += /usr/local/lib/libavcodec.a libs += /usr/local/lib/libavutil.a libs += /usr/local/lib/libavformat.a libs += /usr/local/lib/libswscale.a   sources += main.cpp 

.cpp:

extern "c" { #ifndef __stdc_constant_macros #  define __stdc_constant_macros #endif  #include "libavcodec/avcodec.h" #include "libavformat/avformat.h" }  #include <stdio.h>  int main() {     avformatcontext *pformatctx;     av_register_all();      const char* fil = "/home/cits/desktop/movfile.mov";      if(avformat_open_input(&pformatctx, fil, null, null)!=0)     {         return -1; // couldn't open file     }      if(avformat_find_stream_info(pformatctx, null)<0)     {         return -1; // couldn't find stream information     }      return 0; } 

any ideas??

thanks in advance.

your .pro file should read like:

qt += core gui   includepath += \     /usr/local/include  libs += -l/usr/local/lib/ -llibavcodec -llibavutil -llibavformat -llibswscale   sources += main.cpp