[gst-devel] Prblm: link error when X overlaying using gst_x_overlay_set_xwindow_id (undefined reference)?

[Ola Theander]

Dear subscribers

I'm currently working on an application which needs basic video playback
capabilities and GStreamer seems to suite my needs perfectly. Right now I'm
only at the stage where I play around a little to get a feel for how to work
with GStreamer.

My current problem concerns the X overlay feature where you can redirect the
playback of e.g. the xvimagesink to you own widget i.e. the playback is
embedded in your application. To enable the overlay I use the
gst_x_overlay_set_xwindow_id() method where I provide the winId of the
target window as a parameter. The problem is that the gcc linker complains
about an "undefined reference" for gst_x_overlay_set_xwindow_id() and
gst_x_overlay_get_type() as soon as I include any function calls related to
X overlaying in my code.

If I skip overlaying and let the xvimagesink play the movie in its own
window it works perfectly, so it seems like the issue is the references to
the X overlay functions in GST.

I assume that it some lib that I need to include in the linking process but
I haven't managed to find which one it is. I have looked at the source and
makefiles of several media players e.g. KMPlayer, Kaffeine etc. which all
optionally use GStreamer as their backend but I haven't managed to find out
what they do that I miss. They all use the overlay feature so it's obviously
works if you know how to do it.

Any help with this problem would be greatly appreciated. I've attached the
output of the make process below. Ignore the warnings at the beginning of
the compile, they don't have anything to do with the particular problem as
far as I know.

Kind regards, Ola Theander

c0003-gentoo test X overlay # make
g++ -c -pipe -Wall -W -pthread -march=i686 -O2 -pipe -g  -DQT_NO_DEBUG
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pthread
-I/usr/qt/3/mkspecs/linux-g++ -I. -I/usr/kde/3.4/include -I/usr/qt/3/include
-I/usr/include/gstreamer-0.8 -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include -I/usr/include/libxml2 -o main.o main.cpp
main.cpp: In function `gboolean idle_eos(void*)':
main.cpp:10: warning: unused parameter `void*data'
main.cpp: In function `void cb_eos(GstElement*, void*)':
main.cpp:27: warning: unused parameter `GstElement*thread'
main.cpp:27: warning: unused parameter `void*data'
main.cpp: In function `void cb_error(GstElement*, GstElement*, GError*,
gchar*,
   void*)':
main.cpp:43: warning: unused parameter `GstElement*thread'
main.cpp:43: warning: unused parameter `GstElement*source'
main.cpp:43: warning: unused parameter `gchar*debug'
main.cpp:43: warning: unused parameter `void*data'
main.cpp: In function `void cb_newpad(GstElement*, GstPad*, int, void*)':
main.cpp:58: warning: unused parameter `GstElement*decodebin'
main.cpp:58: warning: unused parameter `gboolean last'
main.cpp:58: warning: unused parameter `void*data'
g++ -c -pipe -Wall -W -pthread -march=i686 -O2 -pipe -g  -DQT_NO_DEBUG
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pthread
-I/usr/qt/3/mkspecs/linux-g++ -I. -I/usr/kde/3.4/include -I/usr/qt/3/include
-I/usr/include/gstreamer-0.8 -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include -I/usr/include/libxml2 -o p3.o p3.cpp
p3.cpp: In member function `long unsigned int MainWindow::getWinId()':
p3.cpp:49: warning: control reaches end of non-void function
g++  -o test main.o p3.o moc_p3.o   -L/usr/qt/3/lib -L/usr/kde/3.4/lib
-L/usr/X11R6/lib -lXext -lX11 -lm -lkdecore -lkdeui -lkio -lgstreamer-0.8
-lgobject-2.0 -lgmodule-2.0 -ldl -lgthread-2.0 -lxml2 -lpthread -lz
-lglib-2.0
main.o(.text+0x2fa): In function `main':
/root/my_kdeapps/test X overlay/main.cpp:105: undefined reference to
`gst_x_overlay_get_type'
main.o(.text+0x31c):/root/my_kdeapps/test X overlay/main.cpp:105: undefined
reference to `gst_x_overlay_set_xwindow_id'
collect2: ld returned 1 exit status
make: *** [test] Error 1