Hi Plox,
Your problem related with you dont give the right path for your "include" and "library" file.
If you have an experienced about Makefile, I think you will not get a problem when using "pro" file.

I am try to get gst library from here http://docs.gstreamer.com/display/Gs...lling+on+Linux
Are you have all required gst library ? If not, try to check the above link.

I am try your code and setting my pro file like this :
Qt Code: 
  1. QT       += core
  2.  
  3. QT       -= gui
  4.  
  5. TARGET = tesgst
  6. CONFIG   += console
  7. CONFIG   -= app_bundle
  8.  
  9. TEMPLATE = app
  10. INCLUDEPATH += /usr/include/gstreamer-0.10/ \
  11.     /usr/include/glib-2.0/ \
  12.     /usr/lib/x86_64-linux-gnu/glib-2.0/include/ \
  13.     /usr/include/libxml2/
  14. LIBS += `pkg-config --cflags --libs gstreamer-0.10`
  15.  
  16. SOURCES += main.cpp
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You only need to look at "INCLUDEPATH" and "LIBS" part (ignore the other part).
The INCLUDEPATH maybe different with the other linux version. So, please check at your error message when compiling your program.
That error maybe related with "you dont have" or "you dont setting the right path".
You can use "find", "locate" or the other command to get the right path for you.

I have success to compile your program using this setting with my Ubuntu 12.04.
Best regards,

Toto