From cahpteer 12, Compiling helloworld.c :

 To compile the helloworld example, use:

       gcc -Wall `pkg-config gstreamer --cflags --libs` helloworld.c \
             -o helloworld 
    
Unfortunately, that doesn't work.
According to David I. Lehn, gstreamer must be versioned, so it should be
for example :
gcc -Wall `pkg-config gstreamer-0.6 --cflags --libs` helloworld.c \
             -o helloworld 

It works better here.